Engine racing

[bikenuts]

Hi Folks

This is my first post and I'm asking for help!

I've got a 95 Mk3. Occasionally, when fuel is running low I think, the engine races but seems to settle down when I turn it on to reserve. This hasn't happened enough for me to be sure of the cause.

Also, when I start it it does race for a while before settling down. This is regardless of whether the choke is on.

I have stripped and cleaned the carb and it all seemed ok.

Any ideas?

Cheers

David

[knackeredMk1]

When the fuel is running low the engine runs away a bit because it is running lean. It will then stop because of fuel starvation or drop back down to 'normal' running if you turn the fuel tap to reserve. This is usual.

It is also quite usual for the engine to rev for a few seconds when started, particularly if not run for a few days. If the engine revs for more than a few seconds or revs very high then this would be unusual.

[fallenmikethebike]

Hi Folks

This is my first post and I'm asking for help!

I've got a 95 Mk3. Occasionally, when fuel is running low I think, the engine races but seems to settle down when I turn it on to reserve. This hasn't happened enough for me to be sure of the cause.

Also, when I start it it does race for a while before settling down. This is regardless of whether the choke is on.

I have stripped and cleaned the carb and it all seemed ok.

Any ideas?

Cheers

David

Hi welcome, now give the carb a severe good leaving alone
Mike

[back off road]

fmtb +1

[bikenuts]

Thanks for the replies folks, I think I'll leave it. The strange thing is my low mileage totally original Mk3 doesn't do it on start up and only a little when the fuel is running low.

The main difference is that the bike in question has an FMF/DEP exhaust system. When it's started after standing for a number of weeks it can race for 30 secs+.

[helisupp]

Definitely not normal then.

[knackeredMk1]

You need to look at the jets the 'racing' bike has. Are they standard .

[bikenuts]

You need to look at the jets the 'racing' bike has. Are they standard .

Yep, standard I'm pretty sure.

But I will see how it goes at the Cambrian Rally next weekend and check them again if there's a problem with the general running.

[mammoth200]

Just a heads up, another thing that can cause the engine to do that is an air leak, or the 'left hand' crank seal, on the magneto side being knackered. Might be worth making sure you have a good seal in the air box and the boots that join it to the carb, and the carb to the engine.