A mate of mine has bought a suzuki 400 gsf i think of the 95/96 vintage..
anyway he was sayin it was running cooler on cylinders 1 and 4 so much so you could touch the exhaust on them cylinders. So he changed plug leads and
caps but it still runs colder on number1 after a good run, 90c of a difference as soon as he stopped.. after ticking over a while it comes down to 30c
of a difference between 1 and 4 2 and 3 still run warmer.
Anyway he says she pulls ok and top end seems good just worried thats somethings not right!!
any ideas or is this a common thing not to be worried about
Tight tappets , incorrect mixture , carbs out of balance could all cause those symptoms
quote:what exaclty so you mean by that?
Originally posted by johnston
So he changed plug leads and caps
02GF74
He put two new leads and caps on cylinder 1 and 4
We knew at start that the 2 outside banks would run cooler they were doin it by feel so i brought my infra red gadget to the party :p
But thought 90c of a difference between the 2 outside cylinders a bit much, the carbs etc were supposidly stripped cleaned and set up not long ago as
it didn't run right when he bought it, although someone else has said their bike hasn't felt right since same man set theirs up.
I was just wonderin if the runnin cooler was normal as i know nothing about bikes, but thought it was weird. Think i'll tell him to go take it
somewhere else to be safe!
Ta for the replys
The outside cyliders will allways run a bit cooler, but..
I would think that if you can still touch the exhast after a run then those cylinders are not working at all 
You need to do some more checks though for sparks at the plug, fuel at the plug etc before you start spending money taking it somewhere.
Has he ever ridden it before this problem, I would have thought there would be a considerable loss of power, but thats not to say it would'nt rev
out?
they will run cooler but not so much that you would notive by hand it will be ouch!! or ouch ouch!! - holding exust in hand and n ot going out shos
the cylinder is not firing.
fitting new plug/leads/cap wonlt cure the problem if the coil is duff - swap the pair of leads to the coil - you will need to swap the LT wiresto
the coil or they wonlt fire at correct time.
also check points - unless electronic igntion, there would be two sets - are they opening on both sets?
yoou need to remve all the plugs then chek there is a spark at each lead.
if there is, then it is fuelling - petrol is not coming out of t he carbs for some reason. remove hoses from tank - carb and see that fule is
flowing.
if so, they you need to strip and reassamble the carbs.
He hasn't had the bike long, when he first got it he said it would "chug" so he got it serviced carbs stripped cleaned etc etc then he
noticed the temp difference at the exhaust downpipes. So he fitted the leads and caps which seems to have sorted part of the problem. But not
fully.
Just the fella that owns it isn't that mechanically minded. For instance when he asked me to put some air in the tyres cos they were a little
soft the front didn't register on the guage and the back only had 12psi