Bad ring or bent valve?

[Anonymous]

There are good days and bad days, this is one that is both. After changing the head gasget and lots of messing around with the cams to get them right (yes you can be 180 out and still run), now I am getting oil out of the breather tub and what smells like exhuast smoke.

This is on a 1980 Gl 850. Did i make a booboo and bend a valve or could I have a bad ring? Dont have a compression tester(next investment).

Any thoughts would help.

[earlfor]

Re: Bad ring or bent valve?

I only see two possibilities. Either you have a bent valve and it isnt closing, or the valve timing is off. The first thing I would do is to recheck and double check to be certain the valve timing is exactly on the marks.

Earl

There are good days and bad days, this is one that is both. After changing the head gasget and lots of messing around with the cams to get them right (yes you can be 180 out and still run), now I am getting oil out of the breather tub and what smells like exhuast smoke.

This is on a 1980 Gl 850. Did i make a booboo and bend a valve or could I have a bad ring? Dont have a compression tester(next investment).

Any thoughts would help.

[Anonymous]

Did check the timing marks thay are bang on so it must be a valve(damn that means take it apart again :? )

Thanks,

[earlfor]

Before tearing it down again, I would beg, borrow or steal a compression tester. If the valve isnt closing, it will be very obvious and there will be no doubt left.

Earl

Did check the timing marks thay are bang on so it must be a valve(damn that means take it apart again :? )

Thanks,

[Don Lobacz]

Yes, check the compression first and let us know the results. Make sure that you pull all spark plugs first and hold the throttle wide open when checking the compression.

[wrench]

Sounds like a bent vavle, a sure sign of a bent valve is a misfire through either the exhaust or back through the carbs, this can be mistaken as incorrect ignition or valve timing so i would double check these first. Smoke and oil coming out the breather if there is no misfire would lead me to believe its a ring problem, let us know what you find out,
Wrench.

[wrench]

Sounds like a bent valve, a sure sign of a bent valve is a misfire through either the exhaust or back through the carbs, this can be mistaken as incorrect ignition or valve timing so i would double check these first. Smoke and oil coming out the breather if there is no misfire would lead me to believe its a ring problem, let us know what you find out,
Wrench.

[argonsagas]

I would follow Earl's suggestions. Since you are complaining now about oil/smoke, it appears you did not have that before, and if you only changed the head gasket, then there is no reason for the rings to suddenly go bad.

As noted, a compression test will instantly show you if you have a bad valve....you won't get any compression on that cylinder, but be aware that you might have the problem on more than one cylinder because that is how it fires. Cylinders 1 and 4 fire together, then 2 and 3, meaning both have the pistons at the top at the same time. If any valve was bent because the cam was off, then the same damage may be found on the other. Check ALL cylinders for compression.

[wrench]

I would follow Earl's suggestions. Since you are complaining now about oil/smoke, it appears you did not have that before, and if you only changed the head gasket, then there is no reason for the rings to suddenly go bad.

As noted, a compression test will instantly show you if you have a bad valve....you won't get any compression on that cylinder, but be aware that you might have the problem on more than one cylinder because that is how it fires. Cylinders 1 and 4 fire together, then 2 and 3, meaning both have the pistons at the top at the same time. If any valve was bent because the cam was off, then the same damage may be found on the other. Check ALL cylinders for compression.

I agree with you Ron, just curious though wheather theres any misfire? and if there is, is it exhaust or intake?

[Anonymous]

Cylinders 1 and 4 fire together, then 2 and 3,

I don't mean to be overly critical, however, I believe that while 1 and 4 are at TDC together, they fire at 360 degrees apart. Same as with 2 and 3.

[jpaul]

If you can't get ahold of a compression tester, just put your finger over the spark plug hole and feel how much compression you have. It's certainly not accurate enough to pick out bad rings, but a bent valve should make a noticable difference between cylinders.

[Anonymous]

Can't find anyone to borrow a comp. tester from so I guess I am going to have to buy one when I get the money, I am getting so fusstrated with this thing I am about ready to take it to a shop, only problem is I'm not a rich man and the shop always thinks I am .

No there is no misfirring just dosent have any power when in gear.

Thanks for the help, if it wernt for you people I wouldn't have gotten this far.

I'll keep trying,