|
Title: thermal efficency Post by: gsxrsam on May 20, 2009, 08:27:23 AM heres an interesting problem for you too mull over.. :o
xj900s divvy, starts, sounds ok, no 1,2,3 exhaust pipes get hot after 30 secs. no 4 cold after 2 mins pull plug lead off no 4, it coughs barks and stops... put back on all good again but still cold :o carbs cleaned and rebuilt and new plugs etc... interesting prob huh lol will be fiddling with it today.. ;) Title: Re: thermal efficency Post by: ByzMax on May 21, 2009, 11:36:57 PM My first route would be to swap plugs with a good cylinder just in case you have a dud new un.
Then if you have a redundant spark system (two coils four cyclinders) then swap the plug leads for that coil. If the problem is still on the same cylinder then check compression and then carb.. Title: Re: thermal efficency Post by: trev on May 22, 2009, 11:03:02 AM you could try taking the plug cap off the cold one with a pair of pliers while the engine is running and hold it close to the top of the plug and make it arc across for a few seconds and then put it back on,its worked for me a few times
Title: Re: thermal efficency Post by: gsxrsam on May 22, 2009, 02:28:25 PM ok, just to mess with your head a bit,
pull off plug lead it stops engine so its firing.. comp test shows minimal difference between all 4 cyls.. swap leads 3/4 over still runs but 4 still cold!! carb now has new emulsion tube and main jet holder in but no difference. fun huh ::) Title: Re: thermal efficency Post by: Manky Monkey on May 22, 2009, 06:17:56 PM Sure it's not something really basic, like a blocked fuel line? There's definitely a spark at the plug if you lay it on the cylinder head & spin the engine over? The spark's not getting diverted somewhere else once it's fitted -like a crack in the head?
Title: Re: thermal efficency Post by: gsxrsam on May 22, 2009, 06:44:31 PM Sure it's not something really basic, like a blocked fuel line? There's definitely a spark at the plug if you lay it on the cylinder head & spin the engine over? The spark's not getting diverted somewhere else once it's fitted -like a crack in the head? one fuel line, it is pump fed [cos im posh], it goes to centre of carbs and all float bowls are full.. if head was cracked i would expect comp tester to show up that, plus you really should be able to hear/see if it was arcing off somewere else ??? :-\ Title: Re: thermal efficency Post by: Manky Monkey on May 22, 2009, 06:45:58 PM Yeah, true. Certainly odd.
Title: Re: thermal efficency Post by: Hillbilly Deluxe on May 28, 2009, 02:28:12 PM Have you ever had this bike running right ? if so what has been changed ?
Title: Re: thermal efficency Post by: gsxrsam on May 28, 2009, 07:17:47 PM ok we have progress,
went up a staggering 44 sizes in main jets and is now on all 4 ??? still wont pull flat out so might need to go higher :o the joys of motoring huh.. |