fouled plugs 72 combat pics

hi having a hard time figuring this out.same thing is happening as before fouling plugs and smoking on decelleration leaking oil out valve cover, engine case etc. seems like to much crank case pressure. i did a top end rebuild. new pistons rings gaskets etc. honed all specs. good rings end play good. everything installed properly. was back firing, adjust carb mikuni it helped, hardly adjust anything. retorqued head. checked crankcase breather clear lots of air flow.head was rebuilt less than 700 miles liquid checked valve seats no leaks, guides were new. pics of plug both the same and engine after top end work.thanks for any help what am i forgetting?





anyone know how to get pics.to set up one on top the other instead of side by side?

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(Photo positions edited by the moderator)

you install your piston rings "top" side up?

also after you type your

yes! bike has 14,000miles had orig. rings right side comp.ring was broken, rings worn sharp edges. cylinder walls good. pistons were good except oil grooves had colapsed old style pistons with long slot in oil groove. no good thanks

Your rings may not have bedded yet but even so that's a lot of oil getting into the chamber so my guess is it's from the top end and not the bottom.

Does it smoke on accel or decel or both?

Do you have intake oilseals fitted and if so are they installed properly(Some patterns can come off guides or get damaged with spring compressor)? Remove carbs and check the intake ports to see if there is any oil puddling here. I did this once! never again.

Do you know what stem clearance the head rebuilder did on the new guides? Shouldn't be too critical though if the inlet seals are working.

Were the heads fully stripped so do you know which way round the rocker shafts are (oil holes and flats point towards valves)?

Is the head swimming in oil? Did you check the rear barrel drain is clear of any gasket sealer?

from the description it sounds like the head is flooded with oil
<smoking on deceleration leaking oil out valve cover>
but it is also pressurizing the crankcase if it is leaking in other places also.
you need to make sure that the cylinder head oil drain from the intake side is not blocked some how. if you have intake valve seals did they get damaged on assembly? smoking on decel indicates intake guides.

I agree, it sounds like the head isn't draining its oil fast enough. Partially plugged oil return passage, maybe, or intake stem seals missing or out of place.

I know with mine, it's not a good idea to let it idle on the sidestand. Oil puddles up around the left exhaust stem, and starts weeping down the stem after just a minute or so.

Guides could be OK but oil could be leaking down the outside of the guide which causes the same smoking on decel problem. This happened to me. Never bad enough to make the plugs look like yours though.

Compression test? Leakdown test maybe? Did you have the cylinder honed before putting in the new pistons/rings?

preston said:

anyone know how to get pics.to set up one on top the other instead of side by side?

Click to expand...

Try not to place the photo Img codes directly at the end of another one, always insert the next one above or below the last one in the order you want the photos to show, leaving at least one clear line space between each Img code line.

Also avoid inserting the Img code lines directly into, or at the end of text.
Always insert the photo Img one line away from any text.

See examples below;-


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Correct:


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Not like this:

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Finally...Please use the 'Preview' button to check that multiple photos display in a vertical sequence in your message before posting.


If you get it wrong, try to use your message edit to correct it if you can, but don't worry too much, as I will normally be able to correct most problems.

If the rocker shafts were installed in the wrong orientation, it can flood the head with oil as well.

Hey mike,
So you made it home ok yesterday?
When we were riding I didn't see any smoke coming out the mufflers when you were on the gas. Maybe a little when decelerating here and there...

aydin made it home fine to bad such a short ride.it sucks stopping at lights when its fouling so bad got to run on choke and keep reved up i hate stalling and have to kick start in traffic.
first figured problem was solved when i found worn and broken rings! apparently not!
so after valves checked out
guides new, i just figured seals were new so i did NOT CHECK hello!
when i pulled head combustion chamber and pistons very oily. inside intake and exaust ports nice no indication of leakage.had orig. copper head gasket it was leaking kept torquing couldnt get it to stop. new gasket seals nice now

any way checked some things
rocker spindals in correctly
compression cold 75lbs. warm left 130 right 140 only 3-4 hrs on rebuild
going to check for drainage next and pull carb see if oil in intake ports
thanks for all the help ridum if there runnin pushum if there not

Did the plugs look the same prior to the rebuild? What shape is the ignition system in? Are those plugs too hot and need the next one down to run cooler? If there is oil in the intake chances are good that the oil or 2nd piston rings are upside down or which ever cylinder that plug came from. I just went through the same with my shovelhead with an upside down oil ring.

yes plugs looked the same as before rebuild both plugs look the same now
brand new boyer electronic
plugs not to hot reg plugs for engine was going to put hotter ones in to burn oil but that an't right
rings are in right made triple sure
thanks

compression cold 75lbs. warm left 130 right 140 only 3-4 hrs on rebuild

this looks more like you might have a ring problem. let it set over night and try the compression test again than put a little oil in the cylinder and try it again. do this with out EVER starting it. if the compression repeats from your earlier test it is rings.

May want to try that compression test dry, then compare a wet (tablespoon of oil down the plug hole) test.

Significantly higher compression from the wet test is the classic sign of bad rings.

Good luck finding and correcting the problem!

Only 3 - 4 hours on rebuild? Sounds like rings didn't bed in. Did you use a non-detergent oil for break-in, like Shell Aero 100? Did you rev it up, load the engine, get it up to operating temp?

I know there are different schools of thought about engine break-in, but the first 20 minutes or so are critical to getting the rings to bed in. If its not done right, cylinders glaze and rings never quite seal.

I used to work for a guy who spent many years as a mechanic and Service Manager at a dealer in LA called BMC West (back in the '60s). His shop once rebuilt a Ferrari 250 TDF engine. They started the engine up, and the sucker burned oil. After knocking heads together for several hours, he called up a friend who was knowledgeable about things Ferrari. He was told to re-hone the cylinders with the coarsest stone available. He said this stone looked like chunks of cinder block. After re-honing, he re-assembled the engine, started up, got it good and hot and revved the hell out of it. After some initial smoking, engine sealed up great and ran like a scalded cat.

It may mean pulling off the jugs and re-honing, but you should be able to re-use the rings if this is indeed the case.

Preston
I was looking at another post that I answered to you about an oil leak problem and now this. it sounds like YOU HAVE A RING PROBLEM. Either you have broken a ring on assembly, miss assembled, not properly honed or just needs to be ridden VERY hard to get them to seat.

Hope you haven't done something like what I did: Installed new pistons (high-compression) and rings into a Ducati 900SS. Broke it in correctly and found myself oil-fouling plugs in the horizontal cylinder. Took it apart after 500 miles or so and found one of the oil control rings ripped out of the groove - left a nice vertical gouge up and down the cylinder wall (Nikasil, too - fortunately was able to buy a used cylinder fairly inexpensively).

Thought I'd been pretty careful on assembly, but maybe I got a bad ring. Also, I had the cylinder off several times during the process, so maybe I got a bit hasty towards the end. And haste surely makes waste.

Anyway, a long way of saying that it does sound like rings and the fact that they're new doesn't mean they're good. Worth rechecking.

At least on the Norton you don't have to drop the engine to pull the heads, like the bloody SS.

ok this morning took a cold compression test 15 kicks per cylinder dry and wet 125lbs that seems like a lot of kicks to get there? im 99% sure rings are in correct and not broken.i installed pistons on bench so i could really take my time and make sure they went in nice. they are gmp pistons and rings italy not the cheap ones.still does not mean they couldnt be bad.but all ring gaps were checked .012 cross hatch honed nice pro job dont know how coarse but looked nice
took her out for a ride today runs alot better seems the little carb adjust really helped no backfiring, pulled away from stop without stalling etc.
still got oil leaks. when i got back from ride pulled intake valve cover no standing oil put small screw driver in to measure maybe only 1/8-1/4 oil on driver.i guess at some point i will need to do breather mod. to fix leaks

rings breakin (manual says) no more than 1/3 throttle for first 1000miles
so i was taking at easy. how ever couple days ago working on it in drive got it pretty hot and keep reving 1000-4500rpm off and on for about min. lots of smoke both pipes took for short ride to cool it down.
today seemed it was smoking only out of left on decell
using valvoline vr1 racing 50 wt.
so sounds like i need to try to breakin rings ride it hard rev to 6500?
change oil to non detergent see if its not to late before honing agian
sound right?
thanks mike

Preston
It takes heat and cylinder pressure to seat rings. I DO NOT like to baby them like the manual say's. 1/3 throttle will not give you much cylinder pressure. take it out and use heavy loads and full throttle which does not mean to rev it to 7000 rpm but a hard pull. follow this link for more info.
http://www.mototuneusa.com/break_in_secrets.htm