1975 600

[JDT]

Is it hitting on both cylinders?

What do the plugs look like after the 15 sec run and die?

[hoosierfarm]

Yes it does rev smoothly, It just starts and acts totally fine, then dies a few seconds later. You can start, hit the throttle a couple of times and it sounds peppy, then almost as if somebody pinched the fuel line off, just dies. Then you can prime again, starts back up, same thing, then dies. My first thought is it is not getting fuel, but it idles a little to long to just run on the primer fuel.... Plus the other day it idled fine for several minutes and I haven't adjusted anything any differently. The thing that puzzles me is the liquid coming out of the exhaust...? Expecially right after it only starts and idles 15 seconds. Would I need to 'lean' the carb some? Which screw, high speed or low speed would I adjust?

THanks for tips.

[hoosierfarm]

It has to be hittin on 2 cylinders it is way to peppy not to be...? The plugs look clean maybe a slight light brown, a litttle moist.

[Matt]

Try turning in the low speed needle. The manual says to turn it in while the sled is idling until it smooths out and then begins to studder because it's lean, then back it out a 1/4 turn.

[HoosierDeereMan]

Lot's of good advice! If adjusting the idle mixture doesn't help, I would revisit the carburetor. You mentioned that it idled for 30 or 40 minutes before and won't now. Also has the dreaded black goo leaking from the exhaust joint. Could it be possible that there is something stuck in the needle and seat causing it not to seal off when the float raises? Instead of starving for gas it could be flooding at idle. This might explain the black goo leaking from the exhaust joint. Is your 600 equipped with a tachometer? Idle should be set at 2200 to 2600 RPM.

Troy

[Snowslider]

Hey Matt what would it mean if when you rev'ed it it bogged down?

Just trying to learn more.
Thx

[JDT]

Plugged exhuast can make it do that.

So can a bad high speed winding on your stator.

And crankseals....

[hoosierfarm]

Pretty sure its not plugged exhaust. I can understand the concern about the seals, but why would it idle and run so good and then now won't, I will have anther look at the carb and the lean adjusting. I will see how that goes.

Thanks

[JDT]

Seals may be 38 years old.
Were intact but brittle when you first started it so they held.

Once engine heated up they fell apart.

They are just waiting for you to take it out for a few mile drive so they can cause your topend to meltdown.

[Matt]

Hey Matt what would it mean if when you rev'ed it it bogged down?

Just trying to learn more.
Thx

Just trying to pinpoint if this is an idle only problem or something bigger.

JDT is pushing the crank seal issue because when they fail it can cause a variety of issues, including a blown engine if you choose to ignore them.

[Snowslider]

How can you tell if your crank seals are shot?

Thx

[WinnipegStPaul9]

How can you tell if your crank seals are shot?

Thx

When you change them

DA

[JDT]

Amen to that.

Thanks DA.

[Snowslider]

Aaaaaaaaaaall rightty then! lol

Thx