04 VE 800 low on power

[astro]

My 800 this year is low on power. Runs fine, just won't get above 6000 rpm. The clutching was right before. Exhaust valves
Didn't look to gumed up. Both cylinders firering. Any thoughts?

 

[summ8rmk]

Bellows on exhaust valves?

Any oil leaking around the ves?

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[05rmksteve]

Bad roller on clutch, bad bushing on clutch weight, sheaves sticking, broken clutch spring, secondary clutch binding, bad motor mount, belt to loose?

 

[whoisthatguy]

Are there any red lights on, in your speedometer or tachometer?
Have you checked all of the bearings, especially the drive axle bearings and rear bogie wheels, for seizure?
Does your headlight dim when you rev the engine?
Does is rev up slower than normal before it hits 6000 RPM?
Does your bright headlight position work?

 

[retiredpop]

Carb jets all cleaned? It could be some varnish in main jets depending how you stored it from last year.
Fresh gas in it?
Mouse nest in exhaust.

 

[whoisthatguy]

I had an issue like that on two sleds and it was two different solutions. On one, the CDI/ECU became defective. So I replace the CDI/CDU. On the other, the main engine electrical harness became defective and it was not getting correct information from the TEMP sensor on top of the engine and the TEMP light in the tachometer gauge was always on. So I replace the main engine electrical harness that connects to the CDI and TEMP sensor.

 

[astro]

Are there any red lights on, in your speedometer or tachometer?
Have you checked all of the bearings, especially the drive axle bearings and rear bogie wheels, for seizure?
Does your headlight dim when you rev the engine?
Does is rev up slower than normal before it hits 6000 RPM?
Does your bright headlight position work?

No lights on. Haven't done the bearing check, will jack the back up and see how the track spins.
Don't think the headlight dims
Revs about the same
Haven't tried the bright headlight.

Primary clutch spring looks good, haven't really torn into the clutches yet.

No oil leaks from the valves

 

[astro]

I had an issue like that on two sleds and it was two different solutions. On one, the CDI/ECU became defective. So I replace the CDI/CDU. On the other, the main engine electrical harness became defective and it was not getting correct information from the TEMP sensor on top of the engine and the TEMP light in the tachometer gauge was always on. So I replace the main engine electrical harness that connects to the CDI and TEMP

With a bad ECU the engine still ran?

 

[summ8rmk]

When it hits 6000 rpm, Does the engine still sound crisp like it's running great?

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[astro]

Not as crisp as it used to. Sounds a little boggy but not missing or ruff.

 

[whoisthatguy]

With a bad ECU the engine still ran?

Yes it ran, but would not rev up at fast as normal and did not go above 6000 rpm or so. The whole CDI/ECU does not all go bad at the same time.

 

[whoisthatguy]

Not as crisp as it used to. Sounds a little boggy but not missing or ruff.

So with no TEMP warning light showing on the dash, then it looks like the CDI/ECU has acquired some kinks. The easiest way to check this is to borrow an airbox off of another identical engine size and model year of Polaris. You are going to then be using both the coil and CDI/ECU from the other sled. If you notice any change, then that was the culprit. You have to buy used ones off of say EBAY or another parts suppliers like the two shops in CLE ELUM Washington, who advertise on the Seattle craigslist.