2004 Yamaha SXvenom ER engine not runing right help!! Hi mileage Owners

M

Martin Hall

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Joined
Feb 6, 2017
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37
Location
DoverFoxcroft Maine
So I just got this sled and I v had som problems trouble shooting being i v always had cat and Polaris or skidoo so it has 10.500 miles it's a red head 600 I got the sled a few days ago put a new battery in it and kyb shocks fixed a broken mid pipe fixed the engine mount that was bolt less any way I take it out for a ride Goes amazing for 22 miles stop to meet my buddy's for a ride sled runs good for about another 2 miles
Then it falls on its face bogged out no foul plugs no pistons detonation all 3 fire 🔥 and if I **** with the choke it will eventually pull through clean but now it will not tack over 8000rpm and sometimes 6000rmp it is strang I believe it is water in the gas blocking the jets or a bad head gasket getting blow bye but I m not mr Yamaha in deep strange waters boys I m not familiar with this brand I also put regular gas in it and I know better but I have been tight on cash and it ran awsom for a while any idea what could cause this what seems to be a lean condition and the carb heaters on .... but this thing is getting snow on the air box pre filter and I can't see how it's getting in and this morning I loaded it on my truck and took it to my dads house and I noticed a small amount of green coolent on my table gate :whine: wtf the hose looks fine on the in tunnel cooler I m assuming it is on the runing board cooler on the clutch side and it looks ok no even average wear on it i kneed the help of someone who eat sleeps and shits Yamaha sx sleds a Yamaha god if you will. I don't have time to trouble shoot all this shit i m a traveling boiler maker welder millwright and I have to make the best of the time home I have between family and sleds help a brother out please!!!!!:whine:
 

And if I can't get a "o this happened to my sled " I ll do my thing carb clean draine fule replace with aviation fule/ comp test / plug spark test /coils test /stator test next step pull engine inspection of coolent hoses fule Line inspect wire harnesses inspection of intake boots and reeds & run psi test on cooling systems soap testing cooling hoses and cooling systems this will take me two days and I will be in the dog house or sleeping at camp no joke ... there has to be a guy who ran theses sleds from new to over 10.000 miles that has been through it all I only fear 2 things electric issues and decapittation by barbed wire fences give me some ideas
 
Start with cleaning carbs really good, drain fuel and replace with fresh stuff, clean both clutches. check the o-rings that go around the needle seats,the needle seats should feel snug when you put them in. those get old, dry up and do not seal like they should which will dump extra fuel in the engine. Is there any coolant under engine by water pump? Sometimes you can get pin holes in the heat exchangers from corrosion, old coolant get gets corrosive, it's a good idea to change coolant at least every five years, I like to use a non silicate type coolant like honda hp coolant or amsoil. The silicates in regular coolant can wear on the water pump seals over time. That really isn't that high for mileage, redhead triples can go a lot longer than that.
 
Im no God or know much about yammis, but from the reading i have done on this site and even the cat site, first 2 things you can do is clean the carbs out (THOROUGHLY) if that doesnt help then check the stator or pick up coil either one or both could be intermittent.

As far as the coolant, check your heat exchangers find the crack drain it dry it jb weld it until you get time to tear it out and put new in.
 
If there is a lot of junk in the carbs you might want to check the in tank filter or put an inline filter in. If the in tank filter came off or apart it could get junk in carbs pretty quickly. Sometimes where the hose clamps on the heat exchanger can get corrosion built up around it and start leaking.
 
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Yea the clutches are all but brand new i will have to clean the carbs and draine the fule it acts like a lack of fule issue so I'm hoping that's all it is and should this sled be tacking 10.000 rpms that is crazy!!!:2strokes: and is it ok to run 87 octane fuel in the red head it seemed to be ruining awesome up until it when into bog mode I put the ISO heat to it today is that not good to use it says safe for two strokes draining the gas any way but for future reference thanks for your advice man I appreciate it.... ps I will be pressure testing the heat exchanger s and hoes also I m going say it is coming from the heat exchanger or a hoes near the bumper because that is where the leek is I must be a very small hole because my coolent is only halfe a quart low I have a spool gun I will find it and weld it up
 
8500 well she is turning up like 10.000 not good so if I remember right a tight belt will cause over rev correct?? And if not I'm going to have to change the secondary spring setting or helix
 
Shaggyr2 What is a good belt to run on my sled I know the one on it is to tight or short because when I had it on the warm up Stand the track would not stop spinning at idle I got this from a 18 year old and he had no idea about sleds besides start it and go I traded a 1999. 550 rmk for this sled so I think I did ok I mean this sled is a good one it just has suffered from neglect and abuse nothing I can't fix I m just trying to get there faster with help from the you all and I m out in brige port ct working on a power plant and I won't be home for 3 weeks lucky my dad is a good sport and works on the sled for me when I m not home we appreciate all the information that saves me time trouble shooting and calling Yamaha and bugging tecks with 10 sleds to fix
 
Based on what you are saying I would assume nothing and just start at the intake and go all the way through it. Check everything as you go. As long as you don't find any serious issues it only takes a few hours even for first timer. Take your time and don't skip anything. Being you know nothing of the history of the sled, I would want to know the condition of all of the parts for my own peace of mind. You can find all you need on here and in the service manual.

As far as the belt - the answer is always run the belt that has been setup for. Sometimes it is easier to go back to stock and tune from there if you don't know what you have.

Don't stop at the clutches, check the entire drive train.

There is a really bright-side IMO - you get to know the sled mechanically a lot better. This is sometimes a very good thing out in the woods or on the trail.

I would definitely do a compression test to see where you are at. It sounds like you have already checked the tops of the pistons so that is good. If you check piston wash it might give you an idea of how rich or lean you might be.

At 10K+ miles it might be a good time to rebuild the top end. At least you would know if your piston skirts are getting sloppy. Replace pistons now might give you several thousand more miles on it.
 
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Martin Hall said:
Shaggyr2 What is a good belt to run on my sled I know the one on it is to tight or short because when I had it on the warm up Stand the track would not stop spinning at idle I got this from a 18 year old and he had no idea about sleds besides start it and go I traded a 1999. 550 rmk for this sled so I think I did ok I mean this sled is a good one it just has suffered from neglect and abuse nothing I can't fix I m just trying to get there faster with help from the you all and I m out in brige port ct working on a power plant and I won't be home for 3 weeks lucky my dad is a good sport and works on the sled for me when I m not home we appreciate all the information that saves me time trouble shooting and calling Yamaha and bugging tecks with 10 sleds to fix
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yamaha belt 8DN-17641-00-00
 
No disrespect meant Martin but I and a few other older guys who happen to know a thing or two about these Sleds "CANNOT UNDERSTAND A THING YOUR ASKING WITHOUT A PERIOD". Good god man turn on your Grammer check on or somthing. Reading your post is mind boggling to my poor brain. Start with your first problem in a well stated sentence and we will help you and move on from there. These are well built engines and for the most part easy to diagnose and fix. What are the problems.
 
super1c said:
No disrespect meant Martin but I and a few other older guys who happen to know a thing or two about these Sleds "CANNOT UNDERSTAND A THING YOUR ASKING WITHOUT A PERIOD". Good god man turn on your Grammer check on or somthing. Reading your post is mind boggling to my poor brain. Start with your first problem in a well stated sentence and we will help you and move on from there. These are well built engines and for the most part easy to diagnose and fix. What are the problems.
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Well the fist problem is the engine will not rev past 6,000 rpm. It sounds like it is hiting a rev limiter. It cuts out and has no power like it is running out of fule. Then if I pull the chock open ,and blip the throttle it will come out of it. But now it is doing it constantly. For example the first time I drove the sled it ran beautiful the first five to 10 miles. Then out of the blue the engine got boggy , and I shut it down. I then proceeded to pull the spark plugs. I checked the pistons wash and the spark plug color. The plugs where a light tan color and the pistons had good wash . The pistons did have some detonation marks on the center. Not breaking Down of the pistons, just carbon leaving the center of the pistons. Small flakes in a perfect circle where the spark plug is . So I limped it home easy pulling the choke and blipping the throttle to help it from leaning out. I got it hom and found the pipe was broken under the the flang by the header I fix the 1/4 half way around the pipe gap by welding it . It ran amazing for 20 miles the next day , then it began doing the same thing again. Sorry for my grammar I
 
Do a resistance check on plug caps. I believe 5000 ohms is what your looking for. Someone correct me if I'm wrong on that, I just woke up. But they do wear out and can cause similar issues.

And the correct spelling for fule is "fuel". My eye twitched everytime I read that lol.
 
ssrrxx said:
Do a resistance check on plug caps. I believe 5000 ohms is what your looking for. Someone correct me if I'm wrong on that, I just woke up. But they do wear out and can cause similar issues.

And the correct spelling for fule is "fuel". My eye twitched everytime I read that lol.[/QUOTE


I do apologize my spelling and punctuation is horrible it's just the way my brain works man . I never did well with it but I was rebuilding complete snowmobiles at age 13 lol
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so it was hitting 10,000 rpms and now it wont go over 6? sounds like your throttle cable is too tight if it sounds like a rev limiter. thatd be your tors
 
I don't think it would even get up to 6000 if it were TORS. Usually when TORS goes off it keeps the rpms down so low that the clutch wont engage. It wouldn't hurt to bypass it anyways just to make sure.
 
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