Bean Can repair

[(RIP) maverick]

Have you got them on the correct sides... They are "handed". marked L and R.

They were upside down when I took them off, have refitted the correctly and tried a spare cover which did not leak in my other airhead but does on this one.

Kenny I will also be surprised if the heads are warped but this bike has more surprises than a fortune cookie!

 

[(RIP) maverick]

Seems like a common problem on some bikes, found this on ADVrider for future reference

Airhead Valve Cover oil leak

Think I will follow Steptoe's advise and use two gaskets

 

[Redboots]

They were upside down when I took them off, have refitted the correctly and tried a spare cover which did not leak in my other airhead but does on this one.

Maybe try some silicone gaskets. Could be the extra "squidgyness" will solve it.

John

 

[(RIP) maverick]

Okay it is not the valve clearances either

I am getting more the idea that it must be fuel related and not electrical. Will swap the coil leads over and see if it misfires on the right hand cylinder. If not then my assumption would be it is fuel related - does this make sense

I paid particular attention to the problem this morning. As said before it runs fine above 2k rpm no missing or anything. If I pull away slowly and keep the revs low and stop it is fine. If I open the throttle up a bit and then slow down the motor dies about 90% of the time or starts running on one cylinder before backfiring.

Could the needle get stuck when I close the throttle and then let too much petrol through killing the plug?

 

[steveo]

have you looked at the bean can yet? take it off and give the shaft a wiggle. bearing can go as mine did.

 

[(RIP) maverick]

Not taken the bean can off yet as I now think even more it is not that. I quickly lifted the tank before leaving work and swapped the coil/plug wires so they now fire the opposite sides.

Thinking that if the backfire moves over to the right it is electrical. If it stays on the left it must be fuel. Bugger me did not think what happens if the problem disappears and no backfire at all!?!

I can only guess that the plug wire must have a break somewhere or
did not seat properly before? Rode it all the way home trying to do exactly what I did the past few days but not a single backfire.

 

[(RIP) maverick]

Okay fitted two new spark plugs and plug wires. It's still doing the backfire thing when it gets hot only on the right hand side.

When I accelarate a bit hard (open the throttle wide) and shut the throttle from pull away it tends to die when if I don't try to keep it idling and then backfires.

Other than that runs fine

I have not had time to take the beancan off but thinking this is more a carburettor issue. Would a sticky needle or dodgy floats be able to cause something like this

 

[MickDB1]

Might sound daft but just check you have not got a frayed throttle cable stopping the slide seating every time you shut off - or not - if yer follow me

 

[(RIP) maverick]

I actually meant the left hand side! Mick will check the cables as well, the other strange thing is I cannot replicate the backfire if the bike is standing still and just revving it high. It seems to only happen under load when decelerating to near stop. Very baffling.

 

[(RIP) maverick]

Did the HT lead swap again and this time it did actually backfire on the other cylinder so cancelled the carburretor out of the story. Last night I took off the coils and check the ohms across the points as per Haynes although between 1 and 15 got a zero reading instead of the indicated tolerance given in the manual. Check it on my other bike and was the same so left it as that. Between terminal 15 and the HT lead got a reading within the limits as per the manual.

I then started putting the lot together and for some reason there was an extra plug on the one coil and checking the wiring diagram should not be on the coil at all. Took this off, made sure all the earth points were good and the backfire is gone. Now I have no idea how or when that plug got onto the terminal but can only think midst a very confusion late evening trying to sort the problem for MOT that I put something back incorrectly.

Will check again on my way home tonight and fingers crossed it is sorted. The bike seems to run fine and everything is working without the terminal that I took off