09 summit popping while running

[the_bn]

Hi, I'm having problems with my 09 800 summit and looking for some help. I put a new crank and top end in it this fall. I had it out for a ride, It was running well. I made it 45 miles and it lost power and is now popping randomly at any engine speed. It's not coming out of the exhaust, a backfire through the carbs I would think, but I don't really feel any pressure coming out of them. The pto side appears to be rich. It has good compression. I have pulled the top end off and replaced the winderosa base gasket with a ski doo one, everything looked ok. I have tried new plugs, I replaced one wire, it would not snap on to the plug properly. I pulled the fly wheel off to make sure the keyway was still in place. I have checked the resistance and voltage of the pick up coils. I have pulled the carbs apart twice and have not found anything wrong. I have tried running it with various sensors unhooked, I thought maybe it would run it a limp mode and maybe see if the popping would stop. I pulled the dmp off to check and see if it was plugged, and to check if the actuator would work. It will run some what smoothly still, so I am stumped. It may be time to just bite the bullet and take it in, unless anyone has any good advice for me! Thanks for the help!

 

[Winter Brew]

Did the plugs show any unusual color from coolant?

 

[Summitric]

Did you check the reeds? Are they sealing properly? Any chips/cracks in the reeds?

 

[the_bn]

The reads look ok. The pto side plug is black, but signs of coolant.

 

[Summitric]

There you go.... Top o-rings/seals?

 

[the_bn]

I replaced them when I replaced the base gasket, they looked ok. i'm going to pressure test the engine tonight

 

[pfi572]

Redone cylinder when you did top end?

 

[the_bn]

Ya, I put in redone cylinders in. I pressure tested the engine and it holds 5psi

 

[slededjr]

Had three last year doing same thing. Two had bad plug wires, replaced with ngk. The other had float valve in one of the carbs sticking and loading up with fuel. Check that see what ya find.

 

[the_bn]

The reads look ok. The pto side plug is black, but signs of coolant.

Sorry that should have said no signs of coolant.
I pulled the plug wires out and the inside part from the old wires are both stuck in the coil still. I will fix that and try it out.

 

[Summitric]

You might check the needle and see if its moving inside the carb as well.... The c-clips can fall off the needles and then they sputter and backfire too......

 

[slededjr]

lol @ summitric. forgot about that one. good tip as well. different shim size under each one or packing missing from one also. saw that numerous times as well.

 

[the_bn]

I found my problem. My crank is out of phase, about 60 degrees.

 

[slededjr]

Wow..... that would do it. That's rare, not un heard of but rare. How did you determine that?

 

[the_bn]

I marked tdc for both pistons on my clutch just to see if they were out, the marks are not even close to 180 degrees apart. It's a reman crank, I didn't think that would have happened. The last thing I checked.

 

[tex78]

That's y lots weld them together.

Problem is makes the crank no good for a core

sent while I should be drinking twisted teas

 

[slededjr]

As Tex said. Mine is welded for that reason. Better talk to crank supplier I guess.

 

[SUMMIT TREE]

isn't it always the very last thing you check EH? oh well at least you found it