Possible reason for burning oil?

[Nick762]

So I started the take down of my 81 185s and taking out the cam I realized the little pin that holds the cam bearing in place seems to have ripped the hold in the cylinder head for the pin outwards, could that be why I'm burning so much oil? Everything else looks good, cylinder walls, piston, rings.

I can post pictures if needed

[Nick762]

Heres the pic

[Scootertrash]

The oil needs to get into the cylinder to burn, so I don't think the problem shown in your pic is the reason your motor is burning oil, although it's probably an indication of a different problem besides the oil burning.

Your cylinder, piston and rings can "look" OK, but you won't know if they are out of spec enough to burn oil unless you check the bore diameter, ring end gap, and piston diameter against the specifications in the manual. Bad valve guide seals and worn valve guides can also contribute to oil burning. You can't always tell if the valve guide seals are bad by looking at them

[dougspcs]

So I started the take down of my 81 185s and taking out the cam I realized the little pin that holds the cam bearing in place seems to have ripped the hold in the cylinder head for the pin outwards

I know your concern Nick, though I agree with scooter that is won't have any relationship to the oil burning it may have other implications.

When I disassembled my 200s engine for similar reason I found my cylinder head had the same issue.

I'll be watching this thread with you for other responses.

[Erics350x]

whats you piston clearance and ring gap?

[Scootertrash]

Doug- did you determine the cause of the pin damage? I haven't been into too many of these motors, but I've never seen that type of damage.

ETA: It almost looks like the cam siezed in that bushing at some time and someone tried to pull the cam with some type of puller. (?)

[DeePa]

time for a new head...you need to have the cylinder mic'd and see if its egged out. At this point, Id bore and hone/new piston and rings.

[atc300r]

There are several reasons your engine is burning oil. 1. worn cylinder ,pistons and rings. 2. worn valve seals. 3.If the ring end gaps are lined up they will burn oil.I have a 200s engine with a similar problem.It was rebuilt by previous owner and who ever put it back together didnt line the pin up with the hole before torqing it down.

[Nick762]

What could have caused this?

I can check ring gap today but I don't have a bore guage, is there another way without a bore gauge?
And this piston looked perfect, (build up, but no excessive wear) I'll check the seals, to be honest I'm thinking that's the problem.

[dougspcs]

Doug- did you determine the cause of the pin damage? I haven't been into too many of these motors, but I've never seen that type of damage.

ETA: It almost looks like the cam siezed in that bushing at some time and someone tried to pull the cam with some type of puller. (?)

No, has me stumped..cam looks good and turning freely. The collar only serves as a guide for the cam to rotate on, it doesn't stop the shaft from moving outward and inward. Once the valve cover is removed the cam lifts free..no puller is needed.

The valve cover is the only thing holding that collar in place with the pin to align it..maybe the collar isn't fitting snuggly in the race and is 'walking' around when the engine running??

This is the only thing I can figure.

Nick why did you dislike scooters post?

[dougspcs]

It was rebuilt by previous owner and who ever put it back together didnt line the pin up with the hole before torqing it down.

This may also be the cause..

[Nick762]

I didn't dislike it, I was just sayin it looks brand new, I'm listening to scooter on what to do next.

[Nick762]

And I think I had the same problem, judging by the silicone everywhere haha

[Scootertrash]

Once the valve cover is removed the cam lifts free..no puller is needed.

I wasn't really clear in my post, what I should have said was it looked like maybe the bushing seized on the cam and someone tried pulling the cam with some type of puller instead of removing the valve cover first.

To me it seems like it would be very obvious that the pin wasn't aligned with the locating hole in the head, especially once you tried to put the valve cover back on. I just got done rebuilding my 200S and the way everything fits in the head it seems like it would be hard to screw it up, but when I think back on some of the things I've seen in my years wrenching, I guess anything is possible. :P

Maybe the dislike was an accident?

I used a thin coat of ThreeBond 1194 on my valve cover/head mating surface, just as a precaution.

Here's a set of valve guide seals on ebay. 8 bucks to your door:

http://www.ebay.com/itm/Honda-ATC185...69e559&vxp=mtr

[dougspcs]

And I think I had the same problem, judging by the silicone everywhere haha

Yeah I just had a closer look at mine it's like that too..I think we have our answer.