Maxwell, Fernie, Snopro....XP help please

[tantrumpipeline]

Brand new top end on an 09xp ptek, made it 26km and lost compression on the can side cylinder, plugs looked good, head was milled prior to reassembly, all new gaskets and internals, followed break in procedure with the on off throttle method, I am at a loss with this, common ptek problem or any ideas? Don't have to be one if the gurus to reply, just know these three are pretty knowledgable with this chassis. Thanks in advance for any help

 

[250mark1]

Piston in backwards maybe ?

 

[gibsons]

Piston rings put in upside down maybe?

 

[TROLLCAT]

going to have to open her up to see what going on

 

[ferniesnow]

In all seriousness, I had a few of the 800R's and I had no motor issues. The 2008 was low on compression with minimal run-out on the crank and due for a top end. I don't know how long it went before it was done.

Sorry I can't help you out but I would think something was done incorrectly or a faulty part (ring, pin, etc.) was put in. Tear it apart and take a look.

 

[snopro]

Did you do a squish test after doing the head work? You may have hurt the engine by running to much compression and detonated a hole through the top? Show us pics when you get it apart.

 

[tantrumpipeline]

Did you do a squish test after doing the head work? You may have hurt the engine by running to much compression and detonated a hole through the top? Show us pics when you get it apart.

One of the local shops did the work, if I'm there when the guys open it up ill snap some pics, thanks for the input

 

[neilsleder]

Any little gray specks on the plug when you checked them? If there is that's usually a good sign of a hole burnt through the piston. What kind of pistons did you use? Did you do the rebuild or a shop, if a shop did it I would hope they would warranty it.

 

[maxwell]

Was the entire motor removed or just the top?

 

[retiredpop]

Brand new top end on an 09xp ptek, made it 26km and lost compression on the can side cylinder, plugs looked good, head was milled prior to reassembly, all new gaskets and internals, followed break in procedure with the on off throttle method, I am at a loss with this, common ptek problem or any ideas? Don't have to be one if the gurus to reply, just know these three are pretty knowledgable with this chassis. Thanks in advance for any help

I would suspect this had something to do with it. What kind of fuel were you running?

 

[tantrumpipeline]

Any little gray specks on the plug when you checked them? If there is that's usually a good sign of a hole burnt through the piston. What kind of pistons did you use? Did you do the rebuild or a shop, if a shop did it I would hope they would warranty it.

Engine was out of the machine, 91octane, plugs looked good, mild brown in color, looked at it this morning and he still had the choke on after 26km of trail riding on our way into kakwa yesterday, possible over fueling with all the in and out if the throttle on the trail? I'm guessing the squish test idea Snopro mentioned is the problem, pulls over nice just zero compression on the one cylinder

 

[Wilk INStheWEST]

Engine was out of the machine, 91octane, plugs looked good, mild brown in color, looked at it this morning and he still had the choke on after 26km of trail riding on our way into kakwa yesterday, possible over fueling with all the in and out if the throttle on the trail? I'm guessing the squish test idea Snopro mentioned is the problem, pulls over nice just zero compression on the one cylinder

Well, that certainly wouldn't help.

 

[tantrumpipeline]

Well, that certainly wouldn't help.

not sure what he was thinking, I noticed this morning when I went out to check my trailer, may have been from trying to start it after it died on the trail but it definitely stood out as a possible issue

 

[tantrumpipeline]

If I can I will definitely get pics for you guys to check out, thanks for all the input

 

[teeroy]

Well, that certainly wouldn't help.

it wouldn't cause a loss of compression. it would just foul the plugs, I doubt it was the issue if the plugs looked good. was probably flipped on after the fact

 

[Modman]

it wouldn't cause a loss of compression. it would just foul the plugs, I doubt it was the issue if the plugs looked good. was probably flipped on after the fact

What he said - if plugs looked good then I would say it was kicked on later. As good as the 800 was mileage-wise, it should be almost out of fuel after running 26 kms with the choke full on.

Absolutely no compression means there is a significant leak in the cylinder, hopefully it wasn't too high of compression and not enough octane. What is the compression set at and what elevation were you running? You've already indicated 91 octane.

 

[Bnorth]

If the choke was on it's possible the rich condition washed down the cylinder wall with fuel.

 

[powder junkie]

If the choke was on it's possible the rich condition washed down the cylinder wall with fuel.

How can u drive a sled 26 kms wit choke on?? He wouldve stopped after 2 mins. Take it back. Shop did sumthn wrong

 

[tantrumpipeline]

What he said - if plugs looked good then I would say it was kicked on later. As good as the 800 was mileage-wise, it should be almost out of fuel after running 26 kms with the choke full on.

Absolutely no compression means there is a significant leak in the cylinder, hopefully it wasn't too high of compression and not enough octane. What is the compression set at and what elevation were you running? You've already indicated 91 octane.

I'm not sure about his sled specifics but I know he upgraded to 91 over the 87 for the head milling but it was very minor machine work, that being said 2smokes are pretty picky, he said he didn't run the choke after the parking lot and was just trying anything to get it to fire after it died, he's going to drop it back off with the shop he had do the work, ill try and remember to update their findings, thanks for the help everyone.

 

[oler1234]

If the choke was on, it would die. Just running down the trail, your barely on the gas. Wide open it might stay running.

where the cylinders replanted or did someone try porting them. Maybe some nikasil was damage or flaked off.

Could be anything really, pull the head and it will tell you.