headache

[jlvdo]

Problem: got the motor back together. Synched carbs. Starts and revs nice up to ~4.5K rpm, then dies. Noticed oil coming out head between cylinder 2 and 3.
Question: could a cylinder head leak cause a such symptoms?
Anyone?

P.S.: I've got a new head gasket and will be putting it in this weekend.

[chef1366]

No. A blown head gasket will make a racket but it will rev. Not well but it will.
It's either carb (including intake and airbox) or ignition related.

[rapidray]

Make SURE when you put it back together you change the orings on the center front 2 head nuts! Ray.

[blowerbike]

revs nice up to 4k.
thats the low speed system working normal.
did you change anything in the carbs like...
remove airbox and rejet for filters ect..
vaccum carbs get funny above 4k when the airbox is removed and a jet kit isnt installed.
16v. heads tend to leak at the front center(cam chain tunnel) after alot of miles..
are you sure its not leaking at the front of the valve cover and running down?
80/81 20 bolt valve covers like to leak in the area you described, just a little higher up.

[jlvdo]

No. A blown head gasket will make a racket but it will rev. Not well but it will.
It's either carb (including intake and airbox) or ignition related.

I've checked the ignition by strobe light--dead on to the timing marks. I've placed paper pods for air filters, and at carb rebuild, I left jets stock, seein' how I live over a mile high. That leaves those infernal carbs...
Been working on those awhile now. The engine seems to runs great up to ~4K, then- dies. Any carb mavens out there? Starts right up from cold using choke. Warms up, idles well, can rev smartly up to said 4K, then stops- even using "throttle english" can't keep the engine going either. The throttle slides have very similar response, have made certain no leaks on diaphragms above. Any suggestions??

[jlvdo]

revs nice up to 4k.
thats the low speed system working normal.
did you change anything in the carbs like...
remove airbox and rejet for filters ect..
vaccum carbs get funny above 4k when the airbox is removed and a jet kit isnt installed.
16v. heads tend to leak at the front center(cam chain tunnel) after alot of miles..
are you sure its not leaking at the front of the valve cover and running down?
80/81 20 bolt valve covers like to leak in the area you described, just a little higher up.

As mentioned in previous post, I left stock jetting 'cause I figured altitude here high enough to compensate for the pods.
Almost certain oil coming from between cylinder and head. I will triple check before I tear everything apart. High miles, I believe the milage is ~32K original miles. Also, I've switched valve cover screws to allen head bolts.

[rapidray]

Are the cams timed CORRECTLY? Ray.

[jlvdo]

Are the cams timed CORRECTLY? Ray.

Yes. I didn't before, and it did not run at all. Took apart, rechecked chain links from sprocket to sprocket, as well as angle of anterior arrow being perpendicular to top of head and timing marks hitting right at same time. Started right up.

[blowerbike]

As mentioned in previous post, I left stock jetting 'cause I figured altitude here high enough to compensate for the pods.
Almost certain oil coming from between cylinder and head. I will triple check before I tear everything apart. High miles, I believe the milage is ~32K original miles. Also, I've switched valve cover screws to allen head bolts.

no airbox.
stock jetting.
altitude will not matter in this case.
bike revs to 4k fine.
jet kit is needed or put the airbox back on.
you can jet and shim the needles till the cows come home.
st.3 kit will make it right...or stock airbox.