Any idea's with sled

[skrat]

Have you tried pulling the belt and checking the clutches? It sure sounds like the rev limiter to me, to consistent to be anything else by the sound. Nm, think maybe the secondary spring is gone?


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[Brojoe]

We pulled the belt and clutch to check springs and they seemed fine.

We we thought we had it fixed and we took it up the switchback and everything seemed to be running good. Took it up the next day to go riding and it acted up again as soon as I gave it some throttle.

Talked to the guy I bought it from and he said on his las trip out to the mtns. a few years ago, it was still a 240 kit. He took it to the turnoff to turtle and it died. He took it down, sent it to Alberta to get fixed and put the 270 kit on. Hasn't rN since and was parked for the season. Also thought it was fixed as it tested well at low elevation.

 

[NM]

Have you tried pulling the belt and checking the clutches? It sure sounds like the rev limiter to me, to consistent to be anything else by the sound. Nm, think maybe the secondary spring is gone?


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If it's clutching. Then it would have to be a combo of too light of weights and wrong springs. We can easily make a four stroke hit rev limiter at low elevation if the clutching is too light.
A bad tether can make them sound that way though.

 

[ROBERTSONYAMAHA]

Hey Brodie, got ur MSG on weekend. Will get in contact with you. Not sure what it could be, it ran strong when we had it. Talked to the captain about it too and sounded like just about everything had been tried on their end too. Very odd. I think Kev had a bit of trouble before he sold it from what I gathered. Which sucks cause i was thinking maybe it was the yamaheater. Is it still in Revy or back in stoon? - Cody

 

[Brojoe]

Hey Brodie, got ur MSG on weekend. Will get in contact with you. Not sure what it could be, it ran strong when we had it. Talked to the captain about it too and sounded like just about everything had been tried on their end too. Very odd. I think Kev had a bit of trouble before he sold it from what I gathered. Which sucks cause i was thinking maybe it was the yamaheater. Is it still in Revy or back in stoon? - Cody

Hi Cody,

Yeah the sled is still out with Captain Ron. Not sure what to do next. There have been a some good ideas from here to check. Kevin said it was acting up his last trip so I am not convinced the Yamaha heat or the tether may be a problem. But they are fairly simple to disconnect and we can rule them out for sure. Give me a call when you have a chance.

Thanks to everyone who has been offering help. I will keep won on the loop once we get this resolved.

 

[Turblue]

This May be a long shot. My apex had a tunnel dump mcx kit. With low fuel On marginal snow days or warm days it would warm up the bottom of the fuel tank due to the tunnel dump to the point where the fuel would boil. You can here it on the secondary fuel pump it would sound rough. Would sound the same as your 1st video. I put a heat blanket between the tanks and tunnel and it was gone. Was a bugger to figure out.

 

[Vipertonytro]

I Notice your Yamaheater light is red. Mine goes red if I have it on the lowest setting. However at the lowest setting my bars get smoking hot. Like so hot you can't grab them with a bare hand. So I have never ran it in the lowest position. Once above low position the light turns green. Maybe mine isn't working right but maybe if your bar heaters are taking too much juice it could be ignition cut out.

 

[Brojoe]

Disconnected both tether and heaters. Didn't seem to make difference.

Last trip rip out I noticed the sled burnt over half tank just from heading up to sugar bowl and back. Also backfired a bit coming down the trail.
Not sure about heating of the fuel because it sputters as soon as the warm up light goes off.

 

[Kibbels]

Disconnected both tether and heaters. Didn't seem to make difference.

Last trip rip out I noticed the sled burnt over half tank just from heading up to sugar bowl and back. Also backfired a bit coming down the trail.
Not sure about heating of the fuel because it sputters as soon as the warm up light goes off.

i just chimed in and... I suspect your MCX harness ... I have seen this before!!! Went thru every electrical connection, checked clutching, checked ECU ... The list goes on. I can give Ron a call in am if ya like or PM me.

Cheers...

 

[Brojoe]

Sent you a pm.

As for the harness, it was replaced when we installed the new MCX box.

 

[bigfish]

Disconnected both tether and heaters. Didn't seem to make difference.

Last trip rip out I noticed the sled burnt over half tank just from heading up to sugar bowl and back. Also backfired a bit coming down the trail.
Not sure about heating of the fuel because it sputters as soon as the warm up light goes off.

if it burnt that much i would suspect a bad injector,the backfire would be from unburnt fuel in cylinder,was it backfiring when you let off the throttle.

 

[NM]

if it burnt that much i would suspect a bad injector,the backfire would be from unburnt fuel in cylinder,was it backfiring when you let off the throttle.

If it has the black MCX injectors they were a Bosch knockoff and had quite a few issues. They would either stick open or closed.
They have since gone back to a genuine Bosch Green injector.

 

[ROBERTSONYAMAHA]

Agreeing with what Neil and Bigfish said Brodie, the black injectors had lots of issues, that being said that's a simple thing to check and I'm sure Ron woulda done that already but best to ask him... - Cody

 

[YamaDad]

These are both longshots and you may have done it already, but they are easy to do. Stick a rag or leather glove in the exhaust and run the sled, it should die within a few seconds, if not, exhaust leak. Carefully check the charge tube where it leaves the tunnel, there is a potential rubbing point that could cause a leak there. It is easy to miss because of the location. My sled (Powderlites) had this and it ran well at low elevation but lost boost at high. If either is the issue the rest of the setup doesn't have a chance. Good Luck.

 

[Brojoe]

Thanks for all the help, but we finally figured out the issue. It was a wire that goes into the wire harness on the stock injector. It was barely making contact.I will have more info once I get back out there.

Thanks,

 

[Tuesday]

Having a similar problem with my sled. However my sled only randomly acts up mid throttle and can get by the stumble spot most times and pull full boost. Going to put in a new TPS even though it shows within spec. So hard to track down a "random" problem.

Glad you found the problem.

 

[sled obsessed]

great thread. lots of good suggestions for troubleshooting.