www.zxrworld.co.uk

Hi just got my bike going after it has been sat for two years and ive got a couple of potential problems:

1) Theres a flatspot around three quarters revs in gears 1-4 (dosent show so much in 5-6) at about 5-6000 revs. I have to open the throttle a bit more and around 7000rpm+ the power kicks in again. Theres no smoke or anything like that from the exhaust. Is it just something that needs some miles to sort out?

2) Pulling away from a standing start the clutch needs to be fed out real slow or i need to give it a fistfull of revs (about 3-4000) to avoid stalling, what would that be then? Again does it just need riding and sort itself out?

3) I only went for a 30 minute ride and the whole thing felt hot, like id blister my finger it i touched the engine. The temp guage was at half way, but it felt hotter than that to me. Coolant is fine, there was no fan coming on- maybe that only works when the temp guage goes to red? Most of the riding in that 30 mins was normal road speeds, though i did get stuck behind a learner going up a narrow hill!

Apart from that i loved it- it was my first proper ride since buying it last month. f*** me is it quick for a 400- i gotta get used to it, my old Honda CB400SF felt a bit wheezy by comparison (but i loved it till i got this!)

Thanks in advance for your replies!

Sorry forgot to say its a 1989 H model.

Also whats the correct revs to have when idling?
Mines going at 2000-2500 rpm any less and it'll stall when cool. Would that help the engine get hot?

Theres the manual on the main site. Idling rpm is around 1200. It could be a number of things. Check float heights and clean carbs/jets for a start. Float height +/- 13mm i think. Try a longer ride

Thanks- i'll check em. Is it possible the fuelling could be too rich or lean? How do i check that?

Well what happened to the bike, why was it silent for 2 years? Are these existing problems? Did you try rebuild it? Running too lean will make the revs hang, running too rich will make them drop. - the carbs have air screws under them when mounted on bike, 1 per carb. If you have standard jets "98", you should be fine at 2 1/4 turns out after screwed all the way in. Screwing clockwise "in" makes it leaner, screwing anti-clockwise "out" makes it richer. You shouldnt really go past 3 turns out and 1 turn in. You want a ballance between rich and lean, maybe a tad bit richer. You should turn your air screws in slowly counting how many full turns and half/quarter turns in, and write them down per carb before tinkering. Also does your fuel pump work? New fuel? Tap switched to on?

Also running lean would make your bike heat up faster. You should go through the h model manual etc otherwise maybe take it to a good guy to diagnose and fix the problems if you cant. Good luck

Thanks- i'll give that a try.
Dunno why the bike was silent for two years, i only bought it in August. The previous owner had a few bikes, i guess he used this one only occasionaly.
I guess these things dont always come up on a short test ride- i'll have sorted in good time though!
She deserves it.

Heating issues are fixed- a quick radiator flush and some fresh coolant did the trick.
Dunno why i didnt think of that to start with! :wanker