Hi folks,

Hope someone heere can help point me in the reight direction.

My bike has started to get quite hesitant at times, misfiring and such. I've checked my plugs and ignition coils they all check out ok, recent new jets in the carb and full carb service carried out, problem continued before and after this also.

The fault was more intermittent at the start but now has become less so.

Havign a read around people seem to suggest it might be a faulty TPS or fuel pump, can anyone advise on how to diagnose either of these. The fuel pump does seem quite noisey so this might be a hint. If it does turn out to be the TPS, can anyone advise where to get one from and if it is easy enough for a competent DIY mechanic to replace?

Cheers

Noone got any ideas?

If you've replaced the emulsion tubes in the carbs, then that first line of inquiry can be ruled out. A double check with mikuni carbs is that the bike will start from cold with no choke, it should not be able to do this. Are the float heights good? They need to be bang-on. What was done during the carb service?

I think on the 'Cat a TPS problem will be reported by the tacho shooting up to 7000rpm when the ignition is turned on.

Are you sure the coils, leads and plugs are good? Plugs may be gapped okay, and look good, but may be knackered. Coils and leads may statically show the correct impedances but be failing under load.

It could be a number of things (crank position sensor, ECU, dodgy plug/socket, crap in a fuel filter etc), can be problematic with 90s 4-pot yams.

My overall guess with be worn emulsion tubes and float heights out.

btw the fuel pump is low pressure delivery, if it clicks/clunks that is probably okay.