Engine Problem

[crazyrickuk]

The last couple of times ive been out on my bike Ive encountered an issue with engine ideling.

It always seems to happen when the bike it warm and I knock it off for a quick break (5-10 minutes)

Upon kick starting the bike the engine idel rev is significantly increased and when I rev the bike the idel increases further (its as if the throttle it sticking).

When its in this stage if im going up an incline or open the throttle full tilt the engine bogs down and starts to die.

Heres what ive done so far:

Removed the air filter - which was absolutly filthy.

Removed the fuel tank and gined access to the top of the carb. Removed the 2 bolts which hold the the throttle cable,spring and carb "float" (not sure what exactly this is called). When the throttle is twisted the float rises and falls in its clyiner freely, and does not stick.

Ive removed this assembley and dripped light oil down into the length of the throttle cable housing.

Has anyone any ideas of what else could be causing this problem? Any help you can give would be much appreciated.

Regards

Richard

[lowbrow]

Hi Richard, there are so many things that could be causing this, but first things first I hope you've washed the air filter, re-oiled it and put it back? The fact that it was filthy shows how necessary it is, especially for stopping dust in the summer. Also what you're calling the 'float' is known as the 'slide'. The floats are in the bottom of the carb and control how much fuel enters the carb, and I'm wondering if this is your problem because it sounds like the motor is flooding while you take a break. Do you turn the fuel off or leave it on? If the bike runs okay until you park it, turn the fuel off until you get back on. If the bike runs okay afterwards then you will know that the fuel valve controlled by the floats is not shutting off as it should. Try that and see what happens. Come back if you need more help. Dave

[g14gav]

Sounds like the carb needs to come off and be blown out with an airline!

Then make sure the screw next to the tickover screw is set up right, probs wants to be 3turns out if ts a dellorto carb!

[crazyrickuk]

thanks for the replies - ill be sure to knock off the fuel next time im out between breaks.

further development -

i oiled the throttle cable and located the slider back in the carb and built the bike back up again.

I took the idel screw right out then put it in with a single turn (so tick over should be a slow as it would go)

I also reset the mixture screw and gave it 3 and 1/4 turns.

I kicked the bike and away she went - tick over good. But with 1 minute once she started getting warm the engine revs started rising and rising.

Any ideas folks? Thinking need to strip er down and take the carb right out. Break it down, clean and rebuild.

What do we think?

Many thanks,

richard

[lowbrow]

Yes, take the carb off, give it a good clean, remove the jets and blow everything thing through with carb cleaner and an air line. Check the float height. Its a long time since I looked at a Dellorto, but I think the brass arms should be parallel with the float chamber face when the carb is inverted. Also make sure the floats actually float! Take the choke plunger out too and make sure there's no muck in there and that it moves easily in the carb body and the rubber sealing face at the bottom of the plunger is good.

Its not necessary to dismantle the slide and needle, but just make sure the needle is held firmly in position in the slide. If the needle can be pushed up inside the slide (and it doesn't return due to spring pressure) its been assembled incorrectly.

Whilst the carb is off take a good look at the inlet rubber and make sure it isn't too stretched or perished; you don't want any air leaks there.

Hope this helps. Enjoy!