Plug Check

[swmichsx]

I checked my plugs a week ago and everything was as it should be. yesterday my sled idled a little funny so i checked the plugs again and 1 of them is a pewter color. any idea what this is indicating? i did not have time to mess with it yet. it runs fine down the trail. it did back fire right off idle 1 or 2 times. i changed that plug but did not have time to ride it.

 

[stein700sx]

The last time my plug was pewter/grey was when I lost that cylinder. Check it again and make sure everyhting checks out.

 

[horkn]

The last time my plug was pewter/grey was when I lost that cylinder. Check it again and make sure everyhting checks out.

Yeah, that does not sound good at all.

Take a look at the top of the piston on that side.

 

[alswagg]

If compression test is good I would still suspect a coolant leak, burning coolant can turn a plug electrode different shades of grey.

 

[swmichsx]

i am going to test compression tomorrow. i just re built the top end 200 miles ago. i hope i didn't loose that hole. looking in the plug hole with a flash light it looks ok.

 

[swmichsx]

The last time my plug was pewter/grey was when I lost that cylinder. Check it again and make sure everyhting checks out.

what caused the loss of your cylinder?

 

[swmichsx]

i rode for an hour or longer and the sled ran great. never missed a beat. but crap happens.

 

[stein700sx]

what caused the loss of your cylinder?

My cylinder ingested the mag side bearing
Lost of aluminum parts flying around inside the cylinder made it gray

 

[swmichsx]

My cylinder ingested the mag side bearing
Lost of aluminum parts flying around inside the cylinder made it gray

was it a crank bearing or the bearing in the piston pin?

 

[stein700sx]

97's had a mag side crank bearing problem. Not enough lubrication to them( two bearings)