mickyd
hi guys and gals , its me back to pick your brains ... just got a cb 500 on a 97 plate with 23k on the clock , good clean bike but it seems to lack in the performance dept ....??? it revs ok but just does not feel like a 50 or so horse power bike .... any info would be great ...
wheelbarrow
Could be restricted
GreasyTony
Have you, or can you give it a compression test Micky?
You would be looking for comformity between cylinder readings, with a difference of not more than 10 - 15%.
I would expect to see a figure of around 100 - 120 psi after 8 - 10 engine strokes with a figure of around 65 - 80 psi on the first stroke, building up to the higher figure as you continue turning the engine.
mickyd
Hi Guys ,
wheely , is it a carb of job to see if its restricted ?
tony , would not know where to start to do the test ?
it does rev ok but just seems very astmatic ????? am i bein to hard on it ?
harry worth
Throw the air filter away and try again, had a cb750 years ago that became sluggish, shop said lob filter over fence I did problem solved.
mickyd
hi harry , so is it ok to run it with no filter ?
wheelbarrow
Micky it's probably restricted by some washers in the carb inlet pipes, take the pipe off and you can easily see them.
mickyd
hi wheely , is it common to find one restricted as far back as 97 ? the previous owner only went up to 70/75 so maybe he did not notice ? mmmmmmmm
harry worth
Just back from pub, no filter no problem, just try if ok get new filter, go easiest way first, if its the original filter it will be -ucked.
Deleted Member
even if its restricted it should have decent grunt - just will start to run out of breath at top end (around 80) but If I remember correctly the Kawasaki ER-5 had a bit more poke than the CB500.
From riding a friends though who had his before restricting it - it had less grunt and more top end before the kit went on.
general service needed? (oil/filter/plugs etc?)
mickyd
Hi guys , just had a look at the service record and its dealer done till 12 k then nothing ? the guy i got it off bought it at 20k and changed the oil and filter , brake pads . so i guess it may need a service ???? thanks for your advice so far ... kev
mickyd
hi all , been out on the 500 today and it seems to be running better ????? having said that the engine is still sort of lumpy on acceleration ?? like its got a slight misfire ???
Deleted Member
it could be - but it is a parallel twin, probably not as lumpy as a GPZ though but I seem to remember our schools bike being lumpy one
mickyd
hi tcat , mmmm by the sound of things its running normally ? this is my first twin .... so maybe its me ?
firebladejohn
hi mickyd have you checked the spark plugs for sooting up what colour are they after youve been riding the bike for a few miles
mickyd
i will have look ? do you think it could be the plugs john ?
firebladejohn
if the plugs are sooting up it could be carb problems