CLCL
New member
Take a look at the attached.. I was running between 3/4 and full throttle for 2-3 miles across the lake. I am running Bender Pipes with the opticool head gasket, rear heat exchanger 165, 165, 167 Jetting with the airbox shelves IN. I have the carb vents attached to the air box. I was running at sea level and it was between 5 and 10 Degs above zero. I was running 92 octane fuel with 1/2 can of red heat. I have had these pipes on for a couple thousand miles with this setup and had no problems, but this was an unusually long run on the lake for me. Any ideas on what the heck caused it? Those pistons and cylinders AND powervalves don't come cheap and I don't know how I am going to keep it from happening again.. I don't think this is a fuel or jetting issue. Does the Center viper cylinder build heat? Did I have a defective piston? Any help/experiences would be greatly appreciated.
at the speed you might have burned it down on the needle. Meaning the needle was still in the main part way....you might want to raise them. I have also seen the pistons break between the rings but then it would have caught the port...
sxr700
New member
- Joined
- Nov 19, 2003
- Messages
- 54
I still think that these vipers are running too much advance in the mid range causing them to pop after a long haul...
...
That is definition detonation
I am not a viper owner, but you are not the first one to have this exact thing happen. The danger area for Ymaha (and most others) is the mid range. I would consider sleds thoughts, but I a also know that some issues had come up on fuel delivery. I dont want to mislead, but I would contact bender.
good luck
That is definition detonation
I am not a viper owner, but you are not the first one to have this exact thing happen. The danger area for Ymaha (and most others) is the mid range. I would consider sleds thoughts, but I a also know that some issues had come up on fuel delivery. I dont want to mislead, but I would contact bender.
good luck
sxr700
New member
- Joined
- Nov 19, 2003
- Messages
- 54
I don't think the problem is the fuel , I think they have too much spark advance, they will probably run with a higher needle , but that will hurt engine performance ...and throttle response ...somthing is not right in these engines after so many failures. the srx's and sx-r don;t have nearly as many problems ...
fuel..
I know that many people have burned these up because of fuel delivery (I think one of the magazines had a discussion topic on this, and found the vent lines modified allowed owners to use SMALLER jets, and keep them together--something in bowl pressure) Again, I only know a bit about it because i do not own a viper, but the above should give you a direction. Actually I believe CPR is the one who figured out the fix I refered to above.
I know that many people have burned these up because of fuel delivery (I think one of the magazines had a discussion topic on this, and found the vent lines modified allowed owners to use SMALLER jets, and keep them together--something in bowl pressure) Again, I only know a bit about it because i do not own a viper, but the above should give you a direction. Actually I believe CPR is the one who figured out the fix I refered to above.
yamyrider
Active member
Hey Blue,
You are right, I also remember reading something about this in a magazine. There was a mod listed to help this but I can't recall what that was.
You are right, I also remember reading something about this in a magazine. There was a mod listed to help this but I can't recall what that was.
jwiedmayer
New member
EGT's
I don't want to sound like I'm sucker punching you but, I would get some cheap egts. Yea they are out there, look at the non digital ultralight airplane gauges made by westach. I've got three of these http://www.ultralight.ca/Gauges.htm mounted on my sled.If you use a probe that is calibrted for the summer every degree under 62' ambient will read 1' higher on the gauge. Its my little safety factor. I have screwed around with my jetting quite a bit after seeing some high temps. You can even see when you have bad gas if you pay attention.
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I don't want to sound like I'm sucker punching you but, I would get some cheap egts. Yea they are out there, look at the non digital ultralight airplane gauges made by westach. I've got three of these http://www.ultralight.ca/Gauges.htm mounted on my sled.If you use a probe that is calibrted for the summer every degree under 62' ambient will read 1' higher on the gauge. Its my little safety factor. I have screwed around with my jetting quite a bit after seeing some high temps. You can even see when you have bad gas if you pay attention.
viper mod
I can not remember the details of the mod either, but I believe it is routing the vent tubes to air box to correct pressure. I dont want to mislead you, but hopefully this gives you a searcing topic. Again, I am always cautious to give info unless I am 100% sure, but you sound frustrated, and I know your not the first one. If CPR cant help cal aaen--They probably wont want to hear you have bender pipes, but you can only change that next time.
Good luck
I can not remember the details of the mod either, but I believe it is routing the vent tubes to air box to correct pressure. I dont want to mislead you, but hopefully this gives you a searcing topic. Again, I am always cautious to give info unless I am 100% sure, but you sound frustrated, and I know your not the first one. If CPR cant help cal aaen--They probably wont want to hear you have bender pipes, but you can only change that next time.
Good luck
TJ500
Member
Could someone post the link to that article or the article itself on here???....
I think this is something we all should be aware of !!!.....
TJ
I think this is something we all should be aware of !!!.....
TJ
ARTICLE FOUND
OK,
I found the article about the above:
snow tech dec 2003 page 36
"fuel flow on triple piped vipers"
I hope this helps!
OK,
I found the article about the above:
snow tech dec 2003 page 36
"fuel flow on triple piped vipers"
I hope this helps!
JJVIPER
New member
i am not sure what to do with vent tubes...i just installed hauck hushers..and the instructions say to unhook the vent tubes fron the air box..and let them hang...thats recomened by hauck...hope it works....thats what i am doing. dont take my word for it..i dont have enough miles to prove anything..
Several knowledgeable pipe designers do not agree with the SnowTech article. I would get input from several of these guys starting with Bender.
hmmm
The snow tech article states that this "fix" was figured out by hauck, and aaen.
That doesnt say 110% sure, but I would trust them as much as Bender.
The snow tech article states that this "fix" was figured out by hauck, and aaen.
That doesnt say 110% sure, but I would trust them as much as Bender.
sol-sask
New member
- Joined
- Sep 8, 2003
- Messages
- 58
the same thing happened to my sx with bender pipes and big bore kit......i let the sled warm up real good gave it a few blurps and then the backfiring started...popped off the head and sure enuf the mag piston was chiped off on the exact spot yours was.....i got a litlle lucky cux the piece shot right out of the exhaust port.....called bender and thier only thoughts were that is was detonation....meaning i was too lean yet my egts were only up to 800 degrees.......what are we suppose to do .....drop the needle one slot or richen the mains...and lose performance.... 
You should listen to Jeff Simons thoughts on it . . .
CLCL
New member
Bender's Response
OK guys I had a long discussion with Justin at Bender today on this issue. He told me that it was likely Detonation caused by poor fuel, or maybe it was the 1/2 can of red Iso that I ran in the tank full of gas. He also told me to double check my float height. He also told me to gut my airbox because it wouldn't make a difference and he told me NOT to unhook my carb vents... Now that I have said all that I am going to respond by saying that it wasn't much help and it still leaves me scratching my head and wanting to bolt the stock pipe back on...
1. Fuel- Well I had used the same fuel for two days straight prior to the burndown with no problems. My buddies that were running right next to me on the lake were using the same fuel. One of my buddies just happen to be on a stock viper. I was at least blurping my throttle, he was holding his wide open the whole time. I don't think it was a fuel issue.
2. Iso- Well I guess this one is possible, however I also doubt it. I have always run Iso with no problems. Sno-Tech even did an article on Iso a year or so ago saying that it was safe in moderation.. On that particular day I ran 1/2 can (4 OZ) to a full tank of fuel... Usually I run a full can.
3. Float height- It is in spec- That rules that one out..
4. Airbox gutting- Well this wouldn't make it blow up either way, but my understanding is that if you gut the airbox for better flow then it can run leaner, I don't think that I would of wanted it any leaner..
Well after all of that they did tell me that they have had very few piped vipers blow up compared to the number that they have sold.. Well that makes me feel much better.. But wait a second.... That doesn't pay for my cylinder and piston now does it?
The last thing that they told me I find VERY interesting. They HIGHLY recommed that any piped viper owner do what they call a head mod.. Basically for $125 they mill out the dome on the center and PTO cylinders to lower the compression.. This they tell me makes it "Safer" and actually produces more power... Now I am not so sure about the power thing, but I do agree that lessening the compression could loosen up the motor a bit and help to eliminate detonation.. When I spoke with Bender in the past there was no mention of a head mod that was "highly recommeded". If I would of known that my motor was "Unsafe" with the pipes on it and it required a head mod then I guess that I would of done it.
What condition would even make Bender come up with such a modification? If there weren't problems with burning pistons, why would they need to come up with a mod.. I don't ever remember paying for mods to any motor that would increase HP by lowering my compression?
I showed the pictures of the piston to my dealer (Larry at North Country Yamaha) and he says that it was heat caused by the motor leaning out or maybe a hot spot in the cylinder.. Now I have to agree with Larry.. But I know that my jetting was not lean, the piston next to it had the same jetting and you can see the wash on it, and I checked the cylinders regularly.. The only thing that I can see that is different from every other ride that I have had with the pipes on is that I was at a high RPM for a long time.. Now I have done a ton of powder riding at high RPM for very long periods of time, but the underhood temps were probably fattening up the jetting. Maybe this is a cooling issue where it is a hot spot in the cylinder that builds up? What do you guys think of Bender's response..
OK guys I had a long discussion with Justin at Bender today on this issue. He told me that it was likely Detonation caused by poor fuel, or maybe it was the 1/2 can of red Iso that I ran in the tank full of gas. He also told me to double check my float height. He also told me to gut my airbox because it wouldn't make a difference and he told me NOT to unhook my carb vents... Now that I have said all that I am going to respond by saying that it wasn't much help and it still leaves me scratching my head and wanting to bolt the stock pipe back on...1. Fuel- Well I had used the same fuel for two days straight prior to the burndown with no problems. My buddies that were running right next to me on the lake were using the same fuel. One of my buddies just happen to be on a stock viper. I was at least blurping my throttle, he was holding his wide open the whole time. I don't think it was a fuel issue.
2. Iso- Well I guess this one is possible, however I also doubt it. I have always run Iso with no problems. Sno-Tech even did an article on Iso a year or so ago saying that it was safe in moderation.. On that particular day I ran 1/2 can (4 OZ) to a full tank of fuel... Usually I run a full can.
3. Float height- It is in spec- That rules that one out..
4. Airbox gutting- Well this wouldn't make it blow up either way, but my understanding is that if you gut the airbox for better flow then it can run leaner, I don't think that I would of wanted it any leaner..
Well after all of that they did tell me that they have had very few piped vipers blow up compared to the number that they have sold.. Well that makes me feel much better.. But wait a second.... That doesn't pay for my cylinder and piston now does it?
The last thing that they told me I find VERY interesting. They HIGHLY recommed that any piped viper owner do what they call a head mod.. Basically for $125 they mill out the dome on the center and PTO cylinders to lower the compression.. This they tell me makes it "Safer" and actually produces more power... Now I am not so sure about the power thing, but I do agree that lessening the compression could loosen up the motor a bit and help to eliminate detonation.. When I spoke with Bender in the past there was no mention of a head mod that was "highly recommeded". If I would of known that my motor was "Unsafe" with the pipes on it and it required a head mod then I guess that I would of done it.
What condition would even make Bender come up with such a modification? If there weren't problems with burning pistons, why would they need to come up with a mod.. I don't ever remember paying for mods to any motor that would increase HP by lowering my compression?
I showed the pictures of the piston to my dealer (Larry at North Country Yamaha) and he says that it was heat caused by the motor leaning out or maybe a hot spot in the cylinder.. Now I have to agree with Larry.. But I know that my jetting was not lean, the piston next to it had the same jetting and you can see the wash on it, and I checked the cylinders regularly.. The only thing that I can see that is different from every other ride that I have had with the pipes on is that I was at a high RPM for a long time.. Now I have done a ton of powder riding at high RPM for very long periods of time, but the underhood temps were probably fattening up the jetting. Maybe this is a cooling issue where it is a hot spot in the cylinder that builds up? What do you guys think of Bender's response..
bender response
Well, I live in that area and justin is the one I would trust most.(at Benders) However, Bender has lost touch with many of the things on newer sleds. If you have ever run a clutch kit you know that they are way off. I would calll Justin back, and tell him everyting checked out, and ask him what he thinks. I personally would call hauck/cpr and ask them what they think.
I would personally do the vent tube, but thats just me. I would NOT have my head modified. Worst case --sell the pipes, and buy slp's (best fit & finish) cpr are good, but you need to force them into position.
SLP IMO--Hey you may loose a few bucks, but it beats being in this position again...
The ISO dry gas is a crock. I have run it for 20 years with modified machines and no problems. (just make sure it is iso)
One last point--(I forget what year your viper is)The 02 vipers were blowing up (once in a while stock) This was originally blamed on cooling, but in 03 they only changed the amount of oil used(increased)--just a fyi if nothing else.
Well, I live in that area and justin is the one I would trust most.(at Benders) However, Bender has lost touch with many of the things on newer sleds. If you have ever run a clutch kit you know that they are way off. I would calll Justin back, and tell him everyting checked out, and ask him what he thinks. I personally would call hauck/cpr and ask them what they think.
I would personally do the vent tube, but thats just me. I would NOT have my head modified. Worst case --sell the pipes, and buy slp's (best fit & finish) cpr are good, but you need to force them into position.
SLP IMO--Hey you may loose a few bucks, but it beats being in this position again...
The ISO dry gas is a crock. I have run it for 20 years with modified machines and no problems. (just make sure it is iso)
One last point--(I forget what year your viper is)The 02 vipers were blowing up (once in a while stock) This was originally blamed on cooling, but in 03 they only changed the amount of oil used(increased)--just a fyi if nothing else.
CLCL, is the vent on your fuel pump silconed shut? If so, I have a theory that plugging the hole can reduce maximum fuel flow. When combined with large main jets, (very thirsty carbs) could cause the fuel level in the bowls to drop on a long WOT pull. Once the fuel level starts to drop, she goes lean, and detonation starts in.
Bigmax
New member
JJViper, You'd be WISE to call Jeff Simon and talk directly to him as your Hauck Hushers are CPR pipes. I've read more than one that Hauck is giving different setups than CPR and they're having trouble.