Bike going slow then fast randomly?

[doctor_prox]

Is it intermittent, like you will be riding along at a certain throttle and then it will just kick in randomly and go fast.

Also when its in neutral and you rev it does it sound sluggish, and when its got lots of power it revs fast and smooth.

The problem with mine was a faulty ignitor unit, fortunately i got one cheap from a breakers for a fiver, SR parts are pretty cheap.

If not that i would first check the ignition leads and try a new spark plug. Simple things first.

How old is yours, is the exhaust rusted badly?

[big dave 1979]

revs well sounds fine but when im riding along the power goes so im stuck at 30mph ish then picks up and goes alot better, but sometimes that can last for a hour or so or not happen at all its a 1994 but it haddent been looked after before i got it it just had a full service strange one i think

[doctor_prox]

Where abouts do you live?
Probably just be the carbs blocked if it hasnt ran for a while. Check the air filter too.

[big dave 1979]

i live in somerset and i have cleand the carb and air box all is clean and clear like i said has new plug oil filter and air filter i have draind the tank no rust so still not sure think i might get a fuel filter and try a new coil what do you think?

[big dave 1979]

hello people bikes still going like a bag of ****e cleaned carb,drained tank,changed jets,just bought new coil just waiting for it to arrive, can anyone help any more as im getting very annoyed as some times its a good bike too ride then its a bag of ****e when its playing up and i try too rev it up, it coughs and farts about then all of a sudden it clears and off i go bloody thing PLEASE PLEASE CAN SOMEONE HELP ME!!!!!!!!!!!!! also it dosent start very well but only sometimes????????? PLEASE SOMEONE HELP!

[doctor_prox]

Sounds just like the problem i had. It was the CDI unit that needed replacing on mine. If you want i can send you the old one and you can see if it changes at all (granted its still broken but not as broken as yours sounds).

Have you properly cleaned the carb, like taken all the jets out and blown it clean?

[doctor_prox]

Also i advise you to go and ask in the workshop forum on www.bikechatforums.com there are loads of knowledgeable guys on there to help.

[Michael]

Wooh, BCF. I'm on there Ride an RS125 myself. Good luck with fixing the problems.

[big dave 1979]

sorted it was the cdi, cheers mate well worth comming on here thanks again Dave

[Zak33]

holy thread revival, Batman

pretend I have no idea what a cdi is, other than an entire engine type with diesel car's in mind.

What was it?

[kaillum]

holy thread revival, Batman

pretend I have no idea what a cdi is, other than an entire engine type with diesel car's in mind.

What was it?

LOL.. only thing I know about is its the 'black box' part of a motorbike electronic ignition... i've had dozens of bikes and only know it as the cdi.. dont know how it works, buts its between the pickup on the flywheel and the ignition coil.. its the bit that tells the ignition coil when to spark..

[nsr125rossi]

hi there i am having the same problem can u tell me did u buy a new cdi or second hand and where from thanks