STALLING CURE!!!

[Timeline]

I had the head off, had a head gasket fail between cylinders. I check valves when off, later second guessing myself, I checked valve clearance again in the sled as well as cam timing thinking maybe a stretched chain might throw it off enough. sled had 10k on it.

If valve adjustment is not addressed the usual result is burnt valves but it could damage head gaskets . Excessive heat in cylinder.
I'd lean more toward tensioner then chain if you have a slack chain rattling . I contemplated installing the R1 manual adjustable tensioner but went with OEM hydraulic in the end.
While checking measurements , check and recheck and recheck again ensuring TDC . This will also help you purchase the proper shims.
10,000k is likely a more accurate time frame for our application in this engine . They all seem to be in this mileage range .
I know if I did my adjustment at say 10,000 k I would not have had felt what I did.

 

[stevewithOCD]

Yes 10,000 to 12,000 miles. These engines are more "on" than "off". Plus with freezing cold temps then over-heating due to lack of snow. Street bikes have a much more consistent temperature range. We run these things near peak rpm's all day. A street bike stops & slows & has to obey speed limits before it's owner gets a speeding ticket. LOL

 

[musselman]

This thread really got me thinking about checking those valves, sure would be nice to have a crisp running sled this year.

 

[tedgoesfast]

Mine was doing it with ,4000 miles cleaned IAC set idle works great now

 

[Rich Kay]

I just thought I would throw this out there and maybe someone might explain what is taking place...... when my apex occasionally does this stall (starting to drop rpms) after being warm and run for a while I will just touch the throttle ever so lightly before it would stall and it comes right back to a steady idle and is fine? I have never looked into things as to what causes it just lived with it as it only does it once and a while? I could check Co settings and see where they are and play with it to see if anything improves or not.. anyway...?

 

[justin gallant]

Justin, great news. Keep us posted on how it goes on snow this year.
Don't mean to rain on your party, but my buddy's higher mileage Apex responded well to the Co adjustment just as yours did, but did not last, and this led him to checking the valve clearance which 100% solved the problem for good. A few hundred kms after Co adjustment, it was back to stalling when coming to a stop on the trail. He had to feather the throttle to keep it going while stopping so it wouldn't die completely.
It is odd that after 18,000kms on your sled with the prior Co settings that this problem is just showing up, time will tell. Cheers man!

well im back after one season running with that same co adjustment. it started to act up on me again so i checked the valve clearance and my exhaust side was way out of wak!!

 

[Snorunner]

Is this a problem with the valve seats not being hardened? In the good old days this was a problem in cars light trucks with the switch from leaded fuel to unleaded fuel. The older heads had to have hardened valve seats installed to correct this?

 

[justin gallant]

No that's Not the case. Valves get tighter on the exhaust side on these normaly not looser.

 

[MrSled]

https://totallyamaha.com/snowmobiles/aaTECH/ausertech/Fuel Ajustment.htm

 

[justin gallant]

Just did valve adjustment ,I reset the CO Value to (0) , installed Excell exhaust and CR10EK plugs on my apex. Now when i have the sled on a stand and snap it i have a delay or a stumble. once its past that it runs fine... any ideas??? to rich to lean? mabby adjust the CO?

 

[MrSled]

Just did valve adjustment ,I reset the CO Value to (0) , installed Excell exhaust and CR10EK plugs on my apex. Now when i have the sled on a stand and snap it i have a delay or a stumble. once its past that it runs fine... any ideas??? to rich to lean? mabby adjust the CO?

Is the sled complexly warmed up?

 

[maim]

Is the sled complexly warmed up?

x2 on the fully warmed up. mine acts funky until it is.

 

[justin gallant]

Is the sled complexly warmed

No it was not completely warmed up. I should have not of revved the thing up before it was anywais lol my bad

 

[BETHEVIPER]

an update on the motor. Friend blew his up, put this same motor in his chassis. The only electrics that were left on the motor was the stator and cam sensor. guess what, it stalls when warmed up. talk about a change of parts. So for now I think he is going to change out the stator. I wonder if though they may read correct ohms, they may have some other issue that effects it enough when the sled leans out for warm idle settings from the factory, it stalls. Shot in the dark. anyone try a stator? I'll report back with what he found. Glad to get the dam thing off the floor and out the way.

for those who havent followed my nightmare. I have check the valves for sealing with the head off and cams removed. checked valve lash with head off and with head on, check cam timing twice, leak down, compression.

 

[Phatboyc]

Any update Betheviper?