well sorry but running 45hp your not going to be able to be clutched good on and off the bottle on a 4 stroke yes but a two stroke no
Hi guys!
I'm really into Nitrous nowdays (thank's to NOS Boy for sending the book)
But... About that ignition. If SRX will retard timing after 8600rpm i believe it's good because with NOS you need to retard it anyways ??
Another thing is, are you running fogger nozzles or similar?
I'm really into Nitrous nowdays (thank's to NOS Boy for sending the book)
But... About that ignition. If SRX will retard timing after 8600rpm i believe it's good because with NOS you need to retard it anyways ??
Another thing is, are you running fogger nozzles or similar?
Great info in these posts Gary!!! How much hp per cylinder before you recommend going to race fuel on a 2-stroke?nosboy said:
Rambunctious
New member
Thaks for the input
gary, I agree with what you're saying, especially the purge system. un necessary. It came with the kit. and it has cause me to waste about 1/4 of the nitrous I have run...or ...um.....bought
I bought this kit used from a neighbor ( after all my research, I wanted CB's kit form Nitruos express. ironically my neighbor had the exact system I wanted from CB) and Bruce has been VERY helpful, especially considering I didn't buy directly from him. I appreciate his help and support.
one thing I counter on is the discussion on heating the liquid/gas in the tank
My physics background tells me that the pressure in the nitrous tank is a result of the Vapor pressure of N2O. above vapor pressure, a gas condenses into a liquid ( similar to Propane in the grill tank)
the vapor pressure of N2O happens to be 900 psi at about 90 degrees.
if the heater ( electric, or antifreeze loop) heats the NOs vapor in the top half of the tank, the pressure will raise because vapor pressure is a function of temperature ) . forcing the liquid NOS through the lines at the pressure of the gas above it. If it heats the liquid. some will vaporize to a new equilibrium pressure in the gaseaous portion ( resulting in the same pressure for a given temperature of the gas)
I think heating the gas will result in a quicker rise in pressure, but the cooler liquid will pull some heat back out. making a controlled heater go on and off till it all settles or equalizes at a given temp,. If you heat the liquid. it will ramp to the equalized pressure more slowly and evenly. but both cases result in a prerssure that is a function of the gas temperature.
that's my theory anyway
the NX kit uses the fogger type nozzles.
I think the srx ignition does help with nitrous because it retards, but I think it retards too much at my current rpm. If I can get the R's while on now to be 8700-8800, I may have a good ignition system setup with some retarding
I am using BR10ECS at 0.30" gap ( 10 for a cooler heat range, "C" for the heavier ground strap for cooling as well.) and C's are recommended on srx anyway
Bruce also recommended BR10EIX. I just don't know how to read plugs well enough to know If I need to go to the EIX.
I may post pics and solicit input. The guys on the drag forums get looking with electron microscopes on their plugs. I have more learning to do before I can read one at their level. ( counting specs on the ceramic )
I spent 3 hours trying to locate the bottle. I wanted some heat from teh exhaust, so I didn't go teh belt guard route. I have a Power INc. can which is 1/2 the width of stock , but my tank would not fit.
placing the tank right above the exhaust manifolds ( in front of the cylinders) is another option. but I would need to weld brackets to the manifolds.
Tip weights are on their way. I have an RPM problem off the NOS so I need to dial that in first, then see the rise in the rpm with NOS.
I'll have to look into teh hammertimes. I really need a "progressive" weight design that doesn't let you over rev
If a guy comes up with a clutch setup that works for both on and off NOS, he might have something.
Ramb
anyone else have nos installed?????????????????????
gary, I agree with what you're saying, especially the purge system. un necessary. It came with the kit. and it has cause me to waste about 1/4 of the nitrous I have run...or ...um.....bought
I bought this kit used from a neighbor ( after all my research, I wanted CB's kit form Nitruos express. ironically my neighbor had the exact system I wanted from CB) and Bruce has been VERY helpful, especially considering I didn't buy directly from him. I appreciate his help and support.
one thing I counter on is the discussion on heating the liquid/gas in the tank
My physics background tells me that the pressure in the nitrous tank is a result of the Vapor pressure of N2O. above vapor pressure, a gas condenses into a liquid ( similar to Propane in the grill tank)
the vapor pressure of N2O happens to be 900 psi at about 90 degrees.
if the heater ( electric, or antifreeze loop) heats the NOs vapor in the top half of the tank, the pressure will raise because vapor pressure is a function of temperature ) . forcing the liquid NOS through the lines at the pressure of the gas above it. If it heats the liquid. some will vaporize to a new equilibrium pressure in the gaseaous portion ( resulting in the same pressure for a given temperature of the gas)
I think heating the gas will result in a quicker rise in pressure, but the cooler liquid will pull some heat back out. making a controlled heater go on and off till it all settles or equalizes at a given temp,. If you heat the liquid. it will ramp to the equalized pressure more slowly and evenly. but both cases result in a prerssure that is a function of the gas temperature.
that's my theory anyway
the NX kit uses the fogger type nozzles.
I think the srx ignition does help with nitrous because it retards, but I think it retards too much at my current rpm. If I can get the R's while on now to be 8700-8800, I may have a good ignition system setup with some retarding
I am using BR10ECS at 0.30" gap ( 10 for a cooler heat range, "C" for the heavier ground strap for cooling as well.) and C's are recommended on srx anyway
Bruce also recommended BR10EIX. I just don't know how to read plugs well enough to know If I need to go to the EIX.
I may post pics and solicit input. The guys on the drag forums get looking with electron microscopes on their plugs. I have more learning to do before I can read one at their level. ( counting specs on the ceramic )
I spent 3 hours trying to locate the bottle. I wanted some heat from teh exhaust, so I didn't go teh belt guard route. I have a Power INc. can which is 1/2 the width of stock , but my tank would not fit.
placing the tank right above the exhaust manifolds ( in front of the cylinders) is another option. but I would need to weld brackets to the manifolds.
Tip weights are on their way. I have an RPM problem off the NOS so I need to dial that in first, then see the rise in the rpm with NOS.
I'll have to look into teh hammertimes. I really need a "progressive" weight design that doesn't let you over rev
If a guy comes up with a clutch setup that works for both on and off NOS, he might have something.
Ramb
anyone else have nos installed?????????????????????
I would thinl if you run a viper box with stright 114 you could use the nos.
I know a guy that has a lot of timing added and is running 20hp per cylinder long as you run enough occtane you will be fine.
I know a guy that has a lot of timing added and is running 20hp per cylinder long as you run enough occtane you will be fine.
IF you can control the timing (by STARTING with 2 or 4 degrees retarded) THROUGHOUT the entire powerband, you could use 92 or 93 octane up to 20hp per cylinder!!! THE STOCK timing is WAY TOO advanced initially and the flame kernal is TOO DIRECT of a shot to the center of the piston to run a FAST fuel (92 or 93). You HAVE to "buffer" the kernal and get MORE WIDTH instead of more direction!!! The direct shot of the spark kernal will DESTROY the piston like hitting it with a ball pein hammer (the ball end) Hitting it in the same spot a few thousand times will tend to superheat the CENTER of the piston, and you could just imagine what will happen... EGT sensors are a MUST and when you get into bigger than 22 and 26 jets, you MAY WANT TO ceramic coat your piston tops and cylinder head domes and exhaust ports!!!! The ceramic coating will help your compression and provide a smoother entry and exit throughout your combustion process ALSO help keep any carbon from creating a hot spot in your combustion chamber and creating an OPPOSING FLAME FRONT (detonation)... YOUR EGT sensors are going to tell you if your motor is ready to LUNCH a piston, and also will tell you just WHAT you can get away with as far as jetting and pressures.... AS FAR AS HEATING up the liquid vs the gas in a bottle of nitrous... THE LIQUID nitrous will (i'm looking for the right word) ABSORB more of the heat through the liquid than trying to heat up the aluminum bottle.. The vapor will have a tendency to act as a "dead air barrier" and try and keep the liquid nitrous colder... The nitrous is brought from the BOTTOM of the tank in a LIQUID form because the RAPID EXPANSION is just what you are looking for... NITROUS is basically STABLE when it is in a confined space (your bottle) and EXPANDS VERY RAPIDLY at atmospheric pressure!!! Take the FREON theory.. When charging an auto with R12 or R 134A. the vapor that boils off the liquid when the can is upright, passes through the manifold gauge and goes into the LOW SIDE of your a/c system.. The compressor is running and the low side is in a VACUUM state.. It takes a LONG TIME and the can gets REAL COLD trying to install VAPOR into the low side.. DOESNT IT?????... NOW,,, turn the can UPSIDE DOWN and try and charge the car with LIQUID... COMES OUT REALLY FAST and charges the car RIGHT AWAY!!!! The can DOES NOT get cold and the freon does NOT LOSE ANY PRESSURE... AS you PULL NITROUS from the bottle (in a vapor) it does the SAME THING as freon does.. Freon (R12) boils (vaporizes) at 26.7 or 27.6 degrees BELOW ZERO (i forgot the spec) and NITROUS VAPORIZES (or boils) at somewhere around 117 degrees BELOW ZERO.. So you see,, getting the LIQUID out of the tank and KEEPING it as a liquid (before it starts expanding) will WORK WAY BETTER than running it through a MILE of tubing... The hoses are SO SMALL and the feed tube in the nitrous bottle SO BIG that ENOUGH of a supply of LIQUID is getting to the solenoid,, and there is NO NEED for a PURGE!!!! The purge just gets the vapor out of the line that expanded from the last time you hit the button.... In a RACECAR,,, Purge is a GOOD IDEA... on a sled,,,,, NOT!!!!!!!
We can talk about OCTANE and boosters and other chemicals later!!!!
Rambunctious
New member
so with .020 jets ( 45HP) will 100 octane be good with a viper box?
what is the timing dfference at 9000 between viper and srx?
if 100 is killing me with the retarded srx timing. will it be right for a viper box?
I need data. I need data !!!
Ramb
what is the timing dfference at 9000 between viper and srx?
if 100 is killing me with the retarded srx timing. will it be right for a viper box?
I need data. I need data !!!
Ramb
Rambunctious
New member
to clarrify
I run 93 octane in the sled gas tank
and 100 in the Nitrous fule tank.
Ramb
I run 93 octane in the sled gas tank
and 100 in the Nitrous fule tank.
Ramb
I don't know ANYTHING about the viper cdi box. So, I cannot tell you if the viper box will work.. The problem EVERYONE runs into,,,is,,, there is around 500 to 700 EXTRA rpm's made when you get on the button.. The clutching and EVERYTHING ELES )for that matter) is designed to run 500-700rpm LESS!!! I know on my 99SRX, I had to go with a cdi box that went to 10,000 rpm. There was a "Y" box and a "Z" box and I first bought the "Y" box, figuring that it would work... Needless to say, I have BIGTIME ISSUES with Pat Hauck... Those boxes were $500.00 a PIECE!!! After getting the CORRECT BOX (from JOHN WHEELOCK at PROLINE) (thanks JOHN) I had to have Mike Decker MAKE ME a set of race pipes (around 1500.00) and have Mark Giamattei do a "port to death" port job on the jugs!!! The PRIMARY clutch was around $1600.00 and a new secondary to boot!!! A killer drive belt that looked like it came off a SPACESHIP and I was ready to race!!! AFTER putting it all together, I took it to NHRA to do some passes.. NEEDLESS TO SAY,,,, NHRA said NO NITROUS,,,NO WAY,,, NO HOW,,,, GO HOME!!!!!! I took the nitrous off and the sled ran REALLY LOW TENS (10.19) on MOTOR ONLY!!!!! That sled would have been in the HIGH EIGHTS with the PILLS I had in there!!!! To make a LONG STORY short,, I sold the sled and bought a racecar!!! The moral of the story is,,,, DECIDE what you want to do with the sled and KEEP it to do WHATEVER you decide... Trying to get the BEST OF BOTH WORLDS doesn't work too well (maybe I JUST CANT figure it out???) UNLESS you want to get into some EXOTIC stuff (oxygenators and chemicals),,, I suggest you use the C14 (114) octane stuff from VP racing fuels and keep it MILD!!!! That way, if you DO HAVE A PROBLEM with LOW fuel pressures or HIGH nitrous pressures,, the 114 will save your motor from DISASTER!!!!.. If you plan on EGT SENSORS in the near future,,, THEN WE CAN HAVE SOME FUN with making you some concoctions that produce REAL HORSEPOWER!!!!
If youre doing .020 nitrous jets, you should be doing .024 fuel jets... The rule of thumb is .004 bigger with the fuel jet.... 20/24 or 22/26 or 24/28 etc,etc,etc... Maybe I am missing something????
arent you running fogger nozzles????
Rambunctious
New member
fogger "type nozzles.
NX branded annodized alum "Y" nozzles
correction: I have 0.018" fuel, and 0.020" NOS jets per the Nitrous express jetting chart.
I want to be "fast" off the gas, and not sacrifice any trail driveability
I want to fill up at the gas station (93 octane) anywhere in the great white north and keep riding.
I want to make it home every time
I want to beat my buddies clutched APEX
so , what I want is to run maybe 100 rpm below optimium off the gas, ( which should be 8400 for a 2000 srx) and make power at NOS rpms. which will then be about 9000.
I have learned that the srx box retards and pukes so much at 9000 that my ignition is spuddering while on NOS.
so i think a viper box ( or simmons, or other) will help.
but I am an engineer so I will not blindly bolt on parts, I want to know why they work before I bolt them on.
hense all my research leading me to a wet/ safe/ adjustable system with monitors for fuel pressure , battery voltage, and NOS pressure. Charts for Jet, etc.
the ability to read plugs (very well), read or know timing under load, and read exhaust temps is what i do not curenty have.
I however, do no want to spend more than the sled's worth on upgrades. I would rather jump to an APEX before doing that. so there is a limit.
I have spent only $450 on a $1400 (new) system ( a steal in my opinion)
so hopefully I will spend $75 more for an ignition fix (viper box?), and $3.00 for some weights and I am good to go.
Ramb
NX branded annodized alum "Y" nozzles
correction: I have 0.018" fuel, and 0.020" NOS jets per the Nitrous express jetting chart.
I want to be "fast" off the gas, and not sacrifice any trail driveability
I want to fill up at the gas station (93 octane) anywhere in the great white north and keep riding.
I want to make it home every time
I want to beat my buddies clutched APEX
so , what I want is to run maybe 100 rpm below optimium off the gas, ( which should be 8400 for a 2000 srx) and make power at NOS rpms. which will then be about 9000.
I have learned that the srx box retards and pukes so much at 9000 that my ignition is spuddering while on NOS.
so i think a viper box ( or simmons, or other) will help.
but I am an engineer so I will not blindly bolt on parts, I want to know why they work before I bolt them on.
hense all my research leading me to a wet/ safe/ adjustable system with monitors for fuel pressure , battery voltage, and NOS pressure. Charts for Jet, etc.
the ability to read plugs (very well), read or know timing under load, and read exhaust temps is what i do not curenty have.
I however, do no want to spend more than the sled's worth on upgrades. I would rather jump to an APEX before doing that. so there is a limit.
I have spent only $450 on a $1400 (new) system ( a steal in my opinion)
so hopefully I will spend $75 more for an ignition fix (viper box?), and $3.00 for some weights and I am good to go.
Ramb
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I prefer the nos systems funnel jets better,,,but,,,like you said, you got what you got!!!! The decision of buying a REAL nitrous system is a VERY GOOD IDEA.. I see people (no names) here that sprays nitrous into the carbs.. HOW STUPID!!!!! Ask REIMOND!!!! He read all about it!!!! I don't recommend reading the plugs,,BECAUSE you are not continuosly using the nitrous!!!! it will give you false readings.. I don't know if a 10,000 rpm SRX box will help you.. It sounds like it will,,but BE CAREFUL!!!! Thats why I recommend EGT sensors.. YOU KNOW WHATS going on!!!! KEEP SAFE and run BIGTIME OCTANE racefuel.. it is more of an insurance policy if you DONT KNOW YOUR CYL TEMPS!!!!
Rambunctious
New member
I'm talkign about reading the plugs after a NOS run and a shutdown with a skidding track ( otherwise the motor just spins and draws in raw fuel for a mile 
)
I just read on the NOS instructions a description of the good and bad plugs.
clean, new looking plugs with some light tan color to the ceramic and no rounding of the ground strap is good. and HEY that's what I had on the runs i checked.
ramb
)I just read on the NOS instructions a description of the good and bad plugs.
clean, new looking plugs with some light tan color to the ceramic and no rounding of the ground strap is good. and HEY that's what I had on the runs i checked.
ramb
Thank's Nosboy, Good info again.
About that viper CDI. I remember it will advance timing not retart compared for SRX CDI?
Rambunctious, how about MSD ign. you can set different ign. for normal/juice? If you find used set it would not be too expencive.
About that viper CDI. I remember it will advance timing not retart compared for SRX CDI?
Rambunctious, how about MSD ign. you can set different ign. for normal/juice? If you find used set it would not be too expencive.
A LOT of people rely on plug readings.. Its kind of hard to try and explain the flame kernel and the direction of the flame front with a hemispherical combustion chamber... The HEMI chamber has a tendency to direct the MAJORITY of the force of the combustion (expansion) to the CENTER of the piston.. Directing it to the CENTER of the piston, opposed to directing it toward the exhaust ports, has a tendency to SWIRL SPENT combustion gasses around the sparkplug,,,thus PREMATURELY MUDDING or dirtying up the sparkplug, compared to various OTHER combustion chamber designs.. Directing the flame front to the EXACT CENTER WILL PRODUCE MORE HORSEPOWER (mopar figured that out in 1951-1952) it DOES have some disadvantages in a CRANKCASE SCAVENGING 2 stroke!!! THE WEAKEST part of your piston is the EXACT CENTER of the piston.. The part where the MOST force and QUESTIONIBLY the most intense heat ABSORPTION occurs!!! (I SAID QUESTIONIBLY!!!) Why do you think the piston MELTS through the center of the piston when you lean it out too bad???? There are a FEW different reasons,,but,,, NOT TO START AN ARGUEMENT or PISS YOU OFF,,, EGT SENSORS are a ZILLION times more accurate than reading plugs!!! I would rather you look at piston wash than reading plugs,,, but piston wash is way harder to read than just pulling the plugs and looking at them... I dont know enough about clutching and gearing the motor to utilize the HORSEPOWER instead of the added RPM's,,,but there are enough guys out here that have been there and done that, to give you specs on WHAT size ramps and what flyweights and what gears to utilize the torque. I wasnt much good with centrifugal forces and payed more attention to biology and chem classes!!! I was watching MYTHBUSTERS last night and i really got into the "summer sausage rocket" that they tested last night on TV!!! NO MATCH for Ammonium percolate,,but,,, VERY INTERESTING!!! They used a bottle of NITROUS to accelerate it and it worked so good that it destroyed their force gauges!!! KINDA makes me want to go get a summer sausage and put it through a GCMS and see WHAT'S in the sausage... I could probably guess thats its the proteins and FATS that are sustaining the accelerant,,, but it could be the ALLSPICE???? (just kidding!!!) Gary Oles nosboy 
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I have a racepak UDX dash on my srx with egt's Gary. What should I be looking at for spikes in temps running nitrous? I would think it would stay near the same with proper fuel? I have to write all 3 egt's down because they're all reading different due to having to mount them in slightly different spots on my manifolds (springs and spring mounts in the way). My dash is programmed to flash a warning if any egt's go above where they are set by me (nice safety feature).
The reason its hard to explain is because the information is incorrect on your flame front travel and head design. You are telling information from a 4 stroke car engine.
The 2 stroke engine as designed back in 1900's was unsuccessfull and it wasnt till mid 1930's that a fellow by the name of Schneurle, a german engineer, that brought the 2 stroke engine up to par, it was the addition of the side transfer ports as we know them being aimed at the REAR of the cylinder wall, this kept the incoming charge from being cancelled by the exh port of earlier designs. This is called the Schneurle loop scavenging method, pateneted in 1925. earlier designs had used deflector pistons to try and keep the mixtrue from being cancelled out the exh port, and was continuely risking piston seizure due to the amount of heat the piston would have to absorb.
Then with continual design improvements the rear boost port was added to the 2 stroke cylinder, this in turn was developed by walter Kaaden in 1952, opposite of the exh port, with the incoming charge being aimed at the rear of the cylinders, this is the port that pushes the mixture to the center of the head!
Moving onto the cylinder head design, its not a hemi head its a squish type combustion chamber on any late model snowmobile engine from the 1970's to now, the early 2 stroke dome head with offset park plugs were called the Quiescent type design, it WAS hemispherical dome with a offset spark plug, the result of this design, again in a 2 stroke engine, was the end gases ignited around the edges of the piston and collides with the flame front of the spark plug, this created detonation and wrecked the engines.
It was the design of the squishband type combustion chamber in which allowed the end gasses to be squished into the center of the head dome or combustion chamber. The flame front now could not travel to the outside edge of the chamber, and travel under the edge of the chamber or squishband as we know it today. The controlling of the front thru this design head allows rapid combustion,the mixture being pushed across the combustion chamber homogenises the air/fuel mixture more completely and mixes any left over exhaust gasses still present with the new fuel/air charge. Such pockets left over from the previous head design mentioned, slowed down and prevented flame propagation.
Rapid combustion means that besides controlling detonation, there is a corresponding decrease in spark advance needed, the closer we can ignite the charge to TDC, the less negative work the engine has to do compressing a burning charge that is trying to expand. Less energy will be lost in the form of heat being transferred to the cylinder head and the piston crown or dome.
When less heat is transferred to the piston , the engine runs cooler and makes MORE power, a cool piston does not heat the trapped charge in the crankcase underside of piston as much and therefore a cooler denser charge enters the cylinder and makes more power! The compact squish type head does this by confining the intense combustion flame front to about 50% of the piston top,just before and after TDC. The reason the heat can also be controlled is advanced ign. timing in a 2 stroke results in excessive heat being applied to the piston, the spark happens before the piston is at TDC, so the gasses and charge are already pre igniting and warming up prior to being squished to the dome and complete combustion can occur , the use of retarded timing puts more heat out in the pipe of the sled, resulting in a lower temp piston crown!
The way to burn a hole in the center of the 2 stroke piston is the wrong heat range spark plug or the use of excessive igntion timing advance, when they are leaned out from incorrect mixture they will always burn off the exh side of the bridge of the piston, exposing the ring to the high combustion temps results in the rings becoming molten and then bending and breaking, resulting in snagged exh ports and damaged engine. The reason this happens is the flame front/combustion temps becomes too hot and it overheats the exh temp, the re entering exh gasses from the expansion chamber pipe burns the exh bridge off.
The 2 stroke engine as designed back in 1900's was unsuccessfull and it wasnt till mid 1930's that a fellow by the name of Schneurle, a german engineer, that brought the 2 stroke engine up to par, it was the addition of the side transfer ports as we know them being aimed at the REAR of the cylinder wall, this kept the incoming charge from being cancelled by the exh port of earlier designs. This is called the Schneurle loop scavenging method, pateneted in 1925. earlier designs had used deflector pistons to try and keep the mixtrue from being cancelled out the exh port, and was continuely risking piston seizure due to the amount of heat the piston would have to absorb.
Then with continual design improvements the rear boost port was added to the 2 stroke cylinder, this in turn was developed by walter Kaaden in 1952, opposite of the exh port, with the incoming charge being aimed at the rear of the cylinders, this is the port that pushes the mixture to the center of the head!
Moving onto the cylinder head design, its not a hemi head its a squish type combustion chamber on any late model snowmobile engine from the 1970's to now, the early 2 stroke dome head with offset park plugs were called the Quiescent type design, it WAS hemispherical dome with a offset spark plug, the result of this design, again in a 2 stroke engine, was the end gases ignited around the edges of the piston and collides with the flame front of the spark plug, this created detonation and wrecked the engines.
It was the design of the squishband type combustion chamber in which allowed the end gasses to be squished into the center of the head dome or combustion chamber. The flame front now could not travel to the outside edge of the chamber, and travel under the edge of the chamber or squishband as we know it today. The controlling of the front thru this design head allows rapid combustion,the mixture being pushed across the combustion chamber homogenises the air/fuel mixture more completely and mixes any left over exhaust gasses still present with the new fuel/air charge. Such pockets left over from the previous head design mentioned, slowed down and prevented flame propagation.
Rapid combustion means that besides controlling detonation, there is a corresponding decrease in spark advance needed, the closer we can ignite the charge to TDC, the less negative work the engine has to do compressing a burning charge that is trying to expand. Less energy will be lost in the form of heat being transferred to the cylinder head and the piston crown or dome.
When less heat is transferred to the piston , the engine runs cooler and makes MORE power, a cool piston does not heat the trapped charge in the crankcase underside of piston as much and therefore a cooler denser charge enters the cylinder and makes more power! The compact squish type head does this by confining the intense combustion flame front to about 50% of the piston top,just before and after TDC. The reason the heat can also be controlled is advanced ign. timing in a 2 stroke results in excessive heat being applied to the piston, the spark happens before the piston is at TDC, so the gasses and charge are already pre igniting and warming up prior to being squished to the dome and complete combustion can occur , the use of retarded timing puts more heat out in the pipe of the sled, resulting in a lower temp piston crown!
The way to burn a hole in the center of the 2 stroke piston is the wrong heat range spark plug or the use of excessive igntion timing advance, when they are leaned out from incorrect mixture they will always burn off the exh side of the bridge of the piston, exposing the ring to the high combustion temps results in the rings becoming molten and then bending and breaking, resulting in snagged exh ports and damaged engine. The reason this happens is the flame front/combustion temps becomes too hot and it overheats the exh temp, the re entering exh gasses from the expansion chamber pipe burns the exh bridge off.
Holy cow!!! I feel like I'm back in school, I sucked at school, Where's my notepad??? Oh ya I have a printer. I love this thread, good info guy's.