Time for rebuild??

[Wade n NC]

2008 SMR510 with 8000 miles. I had been noticing the ignition was missing a little during recent rides. Seemed to be worsening so I put in a new plug yesterday and took it out. No improvement.... still cutting out. When I parked it I noticed oil on the swingarm underneath the airbox. Pulled the air filter and the bottom of it was soaked in engine oil and there was oil in the intake to the throttle body.

Does this indicate it's time for a rebuild or is there something else that could allow engine oil to find it's way to the air filter?? I suppose blowby like this would also explain the missing I was noticing??

Thanks,
Wade

 

[J.R.]

What kind of maintenance have you done so far and when?

Not knowing your situation, I would suggest pulling the top end apart to have a look at the piston and cylinder. You'll need to inspect the connecting rod bearings, upper and lower to decide if it too needs rebuilding. I'd plan on getting a piston kit at the very least

 

[Wade n NC]

I've put around 2K on the bike since I bought it secondhand earlier this year. I've done an oil/filter change previously and checked the valve clearances about 500 miles ago. I'm thinking if a top end rebuild is justified I'll probably go with the 530 kit.

 

[ray_ray]

Do these bikes have the breather hose going from the valve cover to the air box? If it does and the bike was laid over on the right side, oil will drain from the engine to the air box ...

What did the plug look like? Oily or dry?

 

[Wade n NC]

Hasn't been laid over. Plug was light brown and dry.

 

[Up-tite]

Probable indication of excessive blow by, possible rings, valve guides and seals. Ign dropping a spark missfire possible worn main bearings?
8000 miles could use a freshen up rebuild.

Always cheaper than waiting until it lets go.
Later George

 

[ray_ray]

Yep, that oil is coming from some where and if it ain't the breather hose or just dripping off the filter .... must be engine oil ...

I don't understand why the plug color looks good if the piston rings are toast ... not saying it is not toast (?) but oil burning usually means black plugs in cars ... maybe not a bike though ...

 

[Dirtdame]

Dry the oil out of the airbox, then see how the bike runs and how long it takes for more oil to accumulate and the bike to begin missing again. My TE dumps oil into the airbox after a fall, and a little bit blows in there even if I overfill the engine slightly at an oil change.

 

[Juicehall]

My 450 had a problem with two much oil getting in the airbox. The problem with mine was the little aluminum cover that sits at the end of the intake cam that blocks excess oil from going in the breather. Mine had just worn off and then part of it was eaten by the motor! Check and see if yours is still there. I'll try and find a picture of it, but its pretty noticeable if you pull the valve cover. It never did cause a miss fire even thought it did a good job of filling the airbox with oil.

 

[Wade n NC]

I'll take it out for a test ride today if the weather clears. Could oil going thru the throttle body cause misfiring? I'm not real sure how they work but I'd guess it wouldn't hurt it like that.

 

[Slowpoke]

First, I'd do what Dirtdame and Juicehall suggest;

Clean out the airbox and intake boot, then check to see if the oil diverter disc is still in place on the intake cam beside where the vent hose come out of the head.

The missing could easily be caused by raw oil being sucked out of the intake boot into the combustion chamber.

8000 miles - it might need a top end if it was ridden hard a lot. If it was just street ridden mildly, it shouldn't need a rebuild this soon.....

 

[ghte]

Good luck and keep us informed. Love to know the diagnostics and what course of action you undertake.

 

[Wade n NC]

Cleaned up filter, airbox, and intake plenum. Pulled valve cover. Aluminum shield for breather hose was present. Reassembled everything and noticed the negative battery terminal was a little loose. I may have caused this when I swung the battery out to access the air filter. Took it out for a only a couple of miles due to spotty showers. Came in and pulled the filter. Everything was dry. No sign of oil entering plenum through breather hose. And I had no misfiring during the short ride. I'm not sure any of this is conclusive since it was so short. Tomorrow should be nice weather so I will take it out for a good ride and see what happens. Thanks for the suggestions so far. I really appreciate it.

 

[Wade n NC]

Plug on left is plug removed a couple of days ago. Plug on right is new plug after two twenty minute rides.
BTW, this is what I bought. http://www.supermotojunkie.com/showthread.php?95276-2008-Husqvarna-510-smr-supermoto
Sounds like this guy was maybe the second owner and I bought it from the guy that bought it from him. So.... fourth owner? Wow. But I may be the last cuz I won't grow tired of it any time soon.

 

[ray_ray]

Again, I'm no expert, but both look good to me ...

 

[Wade n NC]

Hasn't been laid over. Plug was light brown and dry.

Actually I did lay the bike over on the right side goofing off in some pine straw a month or so ago. Picked it up as fast as it went down with the engine still running. Did that hurt anything? Am I gonna learn something here?

 

[ghte]

This does look promising, have a good ride weather permitting and report back. I think you may just get outta jail here.

 

[J.R.]

Even if things do turn out good, I would suggest doing some exploratory surgery since you have a good amount of miles. You dont want to avoid one lesson and let another hit ya square in the ass

BTW, Nice bike! I was wondering if that ever sold.. I wouldnt mind trading you spoked wheels for those carrozzerria's!

 

[Wade n NC]

Assuming I get to that point JR, I'm hoping there is some guidance out there somewhere on what needs checking.

Thanks. Love the wheels for sure.

 

[J.R.]

You'll need to inspect the cylinder walls, piston, and whatever else you can find in the manual that is a wear item.. I know theres more Im probably forgetting right now..