[garicao]

View attachment 113842

DANG IT MAN! I just soak these new clutch plates for a few hours and only now realized that the jug says it has friction modifiers 🤬🤬😡😡😡🤬😡

I thought since it was a W 50 it would be safe. Apparently I should read things. Man I can't get this right. I guess I'll throw them in and see what happens

You might try drying them off and then soaking them in a light organic solvent like gasoline. Finally soak in non-ec oil.

--garicao

"Life is uncertain. Eat dessert first."

 

[garicao]

If the plates got soaked with friction modifiers, the clutch will slip in less than 1,000 miles. That middle metal piece looks familiar, but can't recall where it goes, or if it even belongs on a CMX. Maybe a PO's kids dropped that junk in there?

Could the middle item be part of a broken off clutch lever?

--garicao

"It seemed like a good idea...at the time."

 

[Yazman]

You might try drying them off and then soaking them in a light organic solvent like gasoline. Finally soak in non-ec oil.

--garicao

"Life is uncertain. Eat dessert first."

So plain old 10w40 for cars is ok to use? The clutch feels great for now. I figure for $22, I'll just ride it till it goes out and then replace.

 

[Emil]

Several of us have been using regular car 10W/40 for years & have had no issues. My 85 has 49,000 miles on it now. My just breaking in the 86, with only 8000 miles, but I'm thinking of only using motorcycle oil from here on out on this one.

 

[flitecontrol]

The STP is the first 10W-40 I'm aware of that contains friction modifiers. Castrol 10W-40 and Shell Rotella 15W-40 are the oils most forum members use. Those oils have been widely used for years with no problems.

Emil, if I mix up a batch of my custom motorcycle oil, and bring it to the Ohio rally, would you be interested in buying some? I'll sell it for 3/4 of whatever you are paying for motorcycle specific oil. Disregard that it is in sealed Rotella jugs. Just let me know how much you want so I can plan ahead. I can probably cover the fuel costs for my trip with the proceeds.

 

[Emil]

Emil, if I mix up a batch of my custom motorcycle oil, and bring it to the Ohio rally, would you be interested in buying some?

The reasons for going with motorcycle specific oil are varied. Partly because there are fewer & fewer 1st generation Rebels around & wanting to be sure that the engine lasts as long as it possibly can between rebuilds. The are no friction modifiers in motorcycle oil & the oil companies are always changing they're formulations. I'm getting more lazy & my eyes aren't what they used to be, so at least this way I should be more able to depend on getting it right even if I have to pay a little more.
I now need to rebuild the 85 engine, as it is making a clacking noise seemingly emanating near the wrist pins. I'll not ride until it blows up! It may be a simple problem/fix, but pushing an engine making unusual noises has never ended well.

 

[flitecontrol]

Castrol 10W-40 and Shell Rotella 15W-40 are the oils most forum members use. Those oils have been widely used for years with no problems.

Forum member Buickguy put over 100,000 miles on his '87 CMX250 using Castrol, and never had an engine issue, including the clutch.

 

[SoakedKarma]

I didn't realize the engine had to be warm and the throttle wide open--once I did that, I got 140psi on the left side! This is also after I adjusted the valve clearances.

140 is rather low for a cylinder that specs at 199 psi.

2nd gen specced out 40 psi less than 1st

 

[Yazman]

140 is rather low for a cylinder that specs at 199 psi.
View attachment 114062

2nd gen specced out 40 psi less than 1st
View attachment 114063

Oh wow, I didn't realize I was 60psi short (and about 75 short in the other). That makes sense why I'm not getting full speed. I'm guessing worn rings or cylinder, worn cam, burnt valves something like that?

 

[SoakedKarma]

a wet vs dry compression test can tell a lot..
squirt a tablespoon of 30w through the plug hole and check compression again..
higher wet figures are indicative of collapsed rings..

Leak down tester to test valve seal and percentage of leak past rings..
shade tree version.
Use a compressor that can regulate output pressure and plumb 5psi to 10psi into cylinder,, listen at exhaust and carb for hiss with cylinder at TDC when valves should be closed.. shouldn't hear anything..
hiss will at oil filler will always be heard, real loud indicates lots of blow-by.

 

[Yazman]

a wet vs dry compression test can tell a lot..
squirt a tablespoon of 30w through the plug hole and check compression again..
higher wet figures are indicative of collapsed rings..

Leak down tester to test valve seal and percentage of leak past rings..
shade tree version.
Use a compressor that can regulate output pressure and plumb 5psi to 10psi into cylinder,, listen at exhaust and carb for hiss with cylinder at TDC when valves should be closed.. shouldn't hear anything..
hiss will at oil filler will always be heard, real loud indicates lots of blow-by.

How hard is a ring job versus a valve replacement? They both sound like major surgery 🥺

 

[SoakedKarma]

proper valve job would entail grinding seat and replacement valve to match..
at the very least knurling valve guides or replacing them..

Rings could be as simple as freeing up collapsed rings and honing cylinders or replacing with new rings & pistons if they are scored.
Both are major procedures..

 

[Yazman]

proper valve job would entail grinding seat and replacement valve to match..
at the very least knurling valve guides or replacing them..

Rings could be as simple as freeing up collapsed rings and honing cylinders or replacing with new rings & pistons if they are scored.
Both are major procedures..

Ride it till it dies it is then 😂. Maybe I'll throw some engine restorer in the cylinder holes and call it a day.

Could I just buy a gently used top end and swap it over? How hard would that be?

 

[SoakedKarma]

Upon tear down you may find rings collapsed and stuck in piston grooves which need to be cleaned out..
Honing cylinders isn't difficult, nor is cleaning caked on carbon out of piston groove with a broken piston ring.
of course pistons could be riding against cylinder wall scoring both..
at this point without further leak down testing as well as internal visual inspection everything is supposition.

Or ride and enjoy, come winter take top end off and have independent shop or MC machinist you're going to find during this summer do machine work that may be needed.. Keep your eye out for good used P&C on ePay

 

[Emil]

A relatively good endoscopic style inspection camera can be had relatively inexpensively at Harbor Freight. That way when you pull the spark plug, you can look in the hole with the camera.
I've got 1 somewhere but I don't know where??? Old-timers strikes again!

 

[Yazman]

Will these $13 fleaBay valves work (just pricing things out in case it is the valves)?. The OEM set are hundreds, and this one is literally $13. But maybe it's made of monkeymetal.

 

[SoakedKarma]

basically 1st and 2nd gen Rebel valve specs are the same except Valve seat width is wider on 1st gen..
part numbers are different and 1st gen intake valve is listed as Unavailable

does your leak down test indicate valves are loosing compression?

 

[Yazman]

basically 1st and 2nd gen Rebel valve specs are the same except Valve seat width is wider on 1st gen..
part numbers are different and 1st gen intake valve is listed as Unavailable

does your leak down test indicate valves are loosing compression?

Left dry: 145psi
Right dry: 115psi

Left wet: 175psi
Right wet: 145psi

Not good. I'm guessing a burnt exhaust valve on the right, and bad rings for both?

This might be it for me. Valve job and rings seem too much work for me to attempt (with kids, wife, job, etc) and too much to pay someone to do (I'm guessing at least $800).

I don't have a compressor so can't do leak down, but it seems like I'm screwed.

 

[Emil]

You can find (as I've said on several occasions), a parts bike pretty inexpensively. Some even with a TITLE! That may resolve all of your issues. Like I said earlier, I got the '86 that is my everyday rider off Craigslist for $200. Give it some thought. I know that you don't have too much room but it's 1 of the best things in this situation.

 

[SoakedKarma]

I really doubt the valves are burnt.. Don't know why you feel they are without proof..
There are Used and New P&C sets for sale on eBay which will likely solve your compression problems.