2020 Release

[Sasquatch]

Now its interesting that for some reason the 1049 suddenly has Valve recession! So either the valves are softer or seats softer but is it possible that the more restrictive exhaust on the Viper holds more heat in the Valve area? More heat can make things softer but spinning a turbo makes more back pressure as well and don't hear of this in the nytros with turbos. Maybe smaller amount and less miles can be the answer to that? I heard fuel as the possible cause but that too would be heat related.

I have to wonder with the 998 turbo what will happen? More power more heat, more back pressure more heat. Cams being different could make a difference only in how fast they close so maybe a fast closing cam could hammer the seats/valves harder! I think though something has changed with the Valve or seat because way to many engines built from 2003 till the Viper and this problem unheard of in that time! If one has to start checking Valves every 5,000 kms as the answer then riding a 4 stroke is no longer the reliable way. We laughed at the two strokes and their top end rebuilds every 3,500 to 5,000 miles but this would kinda put us on par or behind if you include the 250 dollar seasonal oil change!

 

[cannondale27]

Now its interesting that for some reason the 1049 suddenly has Valve recession! So either the valves are softer or seats softer but is it possible that the more restrictive exhaust on the Viper holds more heat in the Valve area? More heat can make things softer but spinning a turbo makes more back pressure as well and don't hear of this in the nytros with turbos. Maybe smaller amount and less miles can be the answer to that? I heard fuel as the possible cause but that too would be heat related.

I have to wonder with the 998 turbo what will happen? More power more heat, more back pressure more heat. Cams being different could make a difference only in how fast they close so maybe a fast closing cam could hammer the seats/valves harder! I think though something has changed with the Valve or seat because way to many engines built from 2003 till the Viper and this problem unheard of in that time! If one has to start checking Valves every 5,000 kms as the answer then riding a 4 stroke is no longer the reliable way. We laughed at the two strokes and their top end rebuilds every 3,500 to 5,000 miles but this would kinda put us on par or behind if you include the 250 dollar seasonal oil change!

I think it’s just the number of them made. More chance for error on assembly.

 

[Sasquatch]

I think it’s just the number of them made. More chance for error on assembly.

Yes always chance of error but does not explain why a guy has new parts assembled and has same error, did the dealer lash them tight to begin with? If normal wear is happening in one quarter to half the time then that would be a huge error in lash.

If you take an overhead cam motor and check the gap first time apart you find different thickness of shims. To have all the valves tight would mean that someone on the motors is using a gauge of half the thickness, or gaping at half the thickness, is that even possible? If lash is correct from factory and they go tight in as low as 5,000 then the valves or seats are wearing out faster then normal! That sounds like a bad supply of not up to par parts or a design flaw.

I know of many Vectors and Nytros of high mileage that have no problems with the motor, this is something new with the Viper! So what changed? That is the million dollar question. Its beginning to sound like another Catastrophe similar to the breaking gears that started with the viper blamed on the ECU and flash after flash to fix it, again something that was not present in the previous models with the same engine!

The draw of the four stroke is run it and change oil, end of maintenance! First check 25,000 miles! Premature valve recession is a huge problem that turns a four stroke into a 2 stroke! I left two strokes behind for that reason 10,000 miles is 3 seasons, 300 hours is Doo's claim to rebuild, that's about 10,000 miles! Yamaha can do better then that!

 

[cannondale27]

Yes always chance of error but does not explain why a guy has new parts assembled and has same error, did the dealer lash them tight to begin with? If normal wear is happening in one quarter to half the time then that would be a huge error in lash.

If you take an overhead cam motor and check the gap first time apart you find different thickness of shims. To have all the valves tight would mean that someone on the motors is using a gauge of half the thickness, or gaping at half the thickness, is that even possible? If lash is correct from factory and they go tight in as low as 5,000 then the valves or seats are wearing out faster then normal! That sounds like a bad supply of not up to par parts or a design flaw.

I know of many Vectors and Nytros of high mileage that have no problems with the motor, this is something new with the Viper! So what changed? That is the million dollar question. Its beginning to sound like another Catastrophe similar to the breaking gears that started with the viper blamed on the ECU and flash after flash to fix it, again something that was not present in the previous models with the same engine!

The draw of the four stroke is run it and change oil, end of maintenance! First check 25,000 miles! Premature valve recession is a huge problem that turns a four stroke into a 2 stroke! I left two strokes behind for that reason 10,000 miles is 3 seasons, 300 hours is Doo's claim to rebuild, that's about 10,000 miles! Yamaha can do better then that!

True. Subpar materials or dirt/belt ingestion becomes very suspect especially after a second time. At 13000mi on mine now I will be checking them. Nothing coming out of Yamaha can be trusted anymore as has been proven more often in last few years.

 

[STAIN]

I have seen 2 Apex's with valves that got tight right after 10k miles so I wouldn't say this is only an issue with the 3 cylinder. Matter of fact I wouldn't call it an issue at all. Of all the motors Yamaha has built how many have had tight valves prematurely? A handful???

 

[cannondale27]

I have seen 2 Apex's with valves that got tight right after 10k miles so I wouldn't say this is only an issue with the 3 cylinder. Matter of fact I wouldn't call it an issue at all. Of all the motors Yamaha has built how many have had tight valves prematurely? A handful???

So far just this one case. Allan has eliminated that to be a issue with his. Reason for all the talk is us Viper owners are looking for any reason why most of our sleds run like crap with all these flashes and why there is so much variability in run quality from one to another. Valves tight made sense but has not been panning out to be the case. More than likely it’s just another shitty tune from factory.

 

[STAIN]

It would interesting to see someone try the 17 and up pickup wheel/ stub shaft assembly on the crank to see the effect on starting. Unfortunately it is @$300.

 

[cannondale27]

Yes it’s interesting to note the Sidewinder motor has the pickup on flywheel side where it belongs. You think they tightened up the tolerances?

 

[cannondale27]

In 15 at dealership we had one that the reluctor wheel spun. That could very well be a reason for variances. I remember suggesting that to Yellowknife when he had so many issues.

 

[Vmax]

Now its interesting that for some reason the 1049 suddenly has Valve recession! So either the valves are softer or seats softer but is it possible that the more restrictive exhaust on the Viper holds more heat in the Valve area? More heat can make things softer but spinning a turbo makes more back pressure as well and don't hear of this in the nytros with turbos. Maybe smaller amount and less miles can be the answer to that? I heard fuel as the possible cause but that too would be heat related.

I have to wonder with the 998 turbo what will happen? More power more heat, more back pressure more heat. Cams being different could make a difference only in how fast they close so maybe a fast closing cam could hammer the seats/valves harder! I think though something has changed with the Valve or seat because way to many engines built from 2003 till the Viper and this problem unheard of in that time! If one has to start checking Valves every 5,000 kms as the answer then riding a 4 stroke is no longer the reliable way. We laughed at the two strokes and their top end rebuilds every 3,500 to 5,000 miles but this would kinda put us on par or behind if you include the 250 dollar seasonal oil change!

You took the words right out of my mouth Sasquatch. Changing the piston/rings on a 2 stroke every 5000 miles (most will go longer depending on how hard you are on the fun throttle) is a whole lot cheaper than a engine re-build on a 4 stroke. It will be interesting to see the long term reliability of a high HP 4 stroke with all of the torque demands on the engine components and drive train.

 

[cannondale27]

You took the words right out of my mouth Sasquatch. Changing the piston/rings on a 2 stroke every 5000 miles (most will go longer depending on how hard you are on the fun throttle) is a whole lot cheaper than a engine re-build on a 4 stroke. It will be interesting to see the long term reliability of a high HP 4 stroke with all of the torque demands on the engine components and drive train.

My buddies tuned Cat Turbo has 15000 mi on it so as long as Yamaha did the turbo motor right I don’t see a problem.

 

[Vmax]

Your buddy has a Cat 4 stroke and you still have him as a friend, oh the shame cannondale………..lol

 

[cannondale27]

Your buddy has a Cat 4 stroke and you still have him as a friend, oh the shame cannondale………..lol

Yea it still runs great but rest of sled is really clapped out. Last year I don’t believe he made a whole ride without breaking down. Kinda hard to be choosy when we are on Cats ourselves!

 

[Snowaddict]

I have seen 2 Apex's with valves that got tight right after 10k miles so I wouldn't say this is only an issue with the 3 cylinder. Matter of fact I wouldn't call it an issue at all. Of all the motors Yamaha has built how many have had tight valves prematurely? A handful???

My '06 Apex had to have a valve adjustment at 10k. Took a few different people/places to diagnose the problem. Luckily, local dealer figured it out and got it running smoothly again.

 

[STAIN]

Yes it’s interesting to note the Sidewinder motor has the pickup on flywheel side where it belongs. You think they tightened up the tolerances?

I believe they did. Speaking with a Canadian dealer last year, he believed the timing under slow engine crank was all over the place due to the ECU's inability to see a consistent crank signal at low speeds. This is made even worse with the lack of a cam sensor for the ECU to compare to and the firing order of the 3 cylinder which actually causes rpm variations during slow crank. He then hooked up a timing light for a Yamaha rep and demonstrated his point. The 17's pick up/exciter wheel is different. Yes the Cat ECU is the problem but this new stub shaft/exciter wheel up may be a cure. I believe he said to get the new stub shaft to fit some relieving(grinding) of the case may be needed.
I asked last year if any 17 or 18 Vipers had any cold start problems but did not get many answers.