[ridetolive]

Hi everyone new to this site but have been riding for the last three years.
Have a 98 F3. Greate bike but a few concerns. When I start up from cold with full choke three cyclenders fire straight away while the fourth is a split second later. It slaps once or twice and then fires. Once it fires it is fine. Could this be carb or piston issue? I also get a ticking sound from cold. Once up to temp sometimes it stops sometimes it continues. Any ideas?

In regards to start up I have checked fuel pump, fuel lines, petcock, fuel filter, air lines and all the air filters. I have checked and cleaned spark plugs, this did not work so have replaced all four with iridium equivilent NGK plugs. Still no different. It was running great before but also bogs down at 4000revs until I get it up to 4200 - 4300revs. I am quite sure it is also running rich at 4000revs.

Any help is gratefully received

[BurtonF166]

Welcome to the forum first off!

It definately sounds like a carb issue. Since it takes #4 to fire a few miliseconds later, its vaccum is less, or not the same as the other 3.

The bog at 4k also is a symptom of out of sync carbs.

When revved, does it take a second to return to idle or does it drop fast as it shoud?

Sync your carbs and that should fix it!

The ticking can be several things, from CCT (cam chain tensioner) to the valves being out of spec. How many miles does she have?
Good luck

[ridetolive]

Thank you

It is smooth when it comes back down. It did get to 4000revs then start jumping between 3500 - 4500 but this only happened just the once.
Is the valve being out of spec a big/costly job?
There is 29934 on the clocks.

[BurtonF166]

Interesting. Syncing the carbs is a simple job and can be done with a $10 tool made from scratch.

Adjusting the valves isnt a giant overhaul but does take some fine mechanical inclination and most definately a service manual. With 30k miles on the clock, and no check on the valves previously, it is definately time to check them since they are due for inspection every 16k miles.

Do you work on your own bike?

[ridetolive]

I try to do what I can but am a little worried about screwing it up and then having to pay big bucks.

I have a full manual and will have a go at the carbs and CCT

I bought the bike of a guy that has his own bike garage and he had stripped the whole thing powder coated the frame and swingarm and rebuilt from frame up. Was running perfect until I put it in for a service and then started playing up after that.

Do you know what sort of price I would be looking at to get the valves adjusted?

Thaks for you help on this.

[BurtonF166]

You had it serviced and then got problems? Strange...should you maybe talk to them about what they did?

Not sure about the UK, but in the US, the valve adjustment, if shims are needed would be about $500....

Carbs and CCT arent too big of a job, can both be done in an afternoon.

Check out this thread. Not quite the same. Turned out to be a blocked vac line due to aircleaner subhousing foam filter.
No load Misfire on 93 cbr900rr

[ridetolive]

Thanks, ill have a go at the carbs and CCt but if that does'nt fix it I will stick it in at a different garage for the valves. Pricey garage but they retune all the track bikes. Had it dynoed there a couple of weeks ago and they said it was running fine and pushing 93.53 not bad for 98 F3 (with sports exhaust)

I will let you know the outcome anyways. Thanks for your help.

[BurtonF166]

Not bad. Let us know how it goes.