[Yazman]

Bought the bike with left (drivers side) cylinder disconnected from head, no air filter. Started up and ran great, drove it 32 miles home (I know that's not good).

Replaced exhaust collar, gasket, and air filter runs great.

Replaced starter clutch (Chinese junk), ran like garbage, put old starter clutch back in (but with new Chinese internals), runs great, but now occasionally makes a "barking" or "honking goose" noise on start up.

Right side exhaust came loose while riding, drive it about 10 miles home. Looked like some oil was bubbling and boiling out of the valve cover gasket. Fixed exhaust, went to bed.

Today: Put some "engine restorer" in the oil, starts rough and stalls when given gas. Rev it to get it moving in first, runs okayish. Still runs rough.

What happened? It used to run 100% flawlessly!

Burnt valves from loose exhaust?
Engine restorer messed something up?
Something went wrong with starter clutch installation?

Help me out fellas

EDIT: Just went for 30 min ride. Seemed better. Still a little hesitating and sounded like backfiring? Liveable, but could be better

 

[Markrkolb]

Have you checked compression? Have you checked for intake leaks? Are you sure the “engine restorer” is okay for the wet clutch?

 

[Yazman]

Have you checked compression? Have you checked for intake leaks? Are you sure the “engine restorer” is okay for the wet clutch?

That's a good point. I think I'll buy a compression gauge and test.

For intake leaks, I'm guessing to spray carb cleaner near intake and see if RPM changes?

I should have researched engine restore; I didn't even think about the wet clutch

EDIT: Engine restore is not to be used on wet clutches. It will glaze over plates. I'm so dumb. I'm gonna change the oil, and hopefully I didn't do too much damage.

 

[flitecontrol]

If it contains the same friction modifiers that some automotive oils have, I doubt the fiber plates can be saved if the clutch has begun to slip in higher gears.

 

[Yazman]

It felt fine when I was riding it. I guess we'll see. I flushed it with "motor flush" (this time I researched to make sure it was okay) and I'm going to refill with Valvoline 10w40 for motorcycles. How bad of a job are clutch plate installs?

I bought new plugs, got the carb soaking in chem dip, going to do valve clearance, and I cleaned the tank with "The Works." Check out what the PO left inside..... not sure what they are lol

 

[flitecontrol]

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?

 

[Yazman]

I just ordered an entirely new clutch from Amazon. Can't believe the whole thing is only $23! Hopefully it's not garbage

 

[Emil]

I'm using a similar one. 12,000 miles on it so far no issues. The splines are already aligned (at least mine were), so, just as the old one can slide off as a set... the new one goes on as a set, with patience & a little dexterity. 30-45 minute job total. Just remember to soak the whole thing in engine oil for at least 4 hours before assembling, I left mine overnight.

 

[Yazman]

I'm using a similar one. 12,000 miles on it so far no issues. The splines are already aligned (at least mine were), so, just as the old one can slide off as a set... the new one goes on as a set, with patience & a little dexterity. 30-45 minute job total. Just remember to soak the whole thing in engine oil for at least 4 hours before assembling, I left mine overnight.

Any kind of engine oil? Or specifically a motorcycle safe oil? Thanks!

 

[Emil]

The same oil as you use in the engine. I just use 10W/40, but I really think that actual motorcycle oil may perform slightly better.

 

[flitecontrol]

I just use 10W/40, but I really think that actual motorcycle oil may perform slightly better.

In the only comparison test I'm aware of, motorcycle specific oils didn't perform as well as automotive oils. More money, less performance, but big bucks for the seller.

 

[Yazman]

But I thought I got into this whole mess because regular oil has friction modifiers?

 

[Emil]

10W/40 hasn't had them yet....

 

[leebrown66]

Avoid the "Energy Conserving" ones.

 

[flitecontrol]

But I thought I got into this whole mess because regular oil has friction modifiers?

All XXW-30 automotive oils in North America contain friction modifiers. As mentioned above, currently, 10W-40 and 15W-40 automotive oils do not. All motorcycle specific oils are safe in wet clutches and do not contain friction modifiers, but they typically cost 3-4X as much as the 40 weight oils.

 

[Yazman]

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

 

[Emil]

I hate it when that happens! 😒

 

[Yazman]

100psi left cylinder

85psi right cylinder

This might be game over boys. I'm guessing burnt valve/worn rings/scored walls, or something awful like that. I think I'll get it running and either live with it or sell it.

 

[leebrown66]

Leaking head gasket, sticky valve(s), valve lash are also a possibility.

Grab a leak-down tester and dig in a little more after checking the clearances.

 

[Yazman]

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.