33 replies to this topic

[WillCarter]

I've got a 1988 mayfair 998 with a stage 1 kit (new carb needle, manifold, lcb exhaust and pancake air filter), the engine's never really been tuned properly after that and the spark plugs are completely black no matter where the screw on the carb is set to. I haven't set the timing either so I was wondering if I just need to do that myself or if there are any set setting for a stage 1 kit 998? Also I painted the engine block and whilst the spark plugs were in and covered in masking tape, could the backfire be due to paint in the block? Also due to it being in the garage for a few months with very little petrol, could another problem be that it's using petrol that's contaminated at the bottom of the fuel tank? I've cleaned the air filter and put it back on the car, the carb still backfires. The mpg is rubbish, maybe 20mpg since it last went out onto the road. Any help for any of these problems would be greatly appreciated. 

[Dusky]

the engine's never really been tuned properly 

[gazza82]

If it's running rich since a needle change is it the right needle? Is it fitted correctly and is the jet worn? There are many reasons for overfueling so you'll have to work through the options one at a time.

 

Paint isn't likely to be the issue but seems you have taken them out which would clean the threads anyway.

 

Old and low fuel could be a problem as it may be sucking up gunk .. that will jam the jet/float needle. Fit a filter between carb and pump or main fuel line.

[WillCarter]

 

the engine's never really been tuned properly 

 

So would you recommend adjusting the ignition timing first? 

[WillCarter]

If it's running rich since a needle change is it the right needle? Is it fitted correctly and is the jet worn? There are many reasons for overfueling so you'll have to work through the options one at a time.

 

Paint isn't likely to be the issue but seems you have taken them out which would clean the threads anyway.

 

Old and low fuel could be a problem as it may be sucking up gunk .. that will jam the jet/float needle. Fit a filter between carb and pump or main fuel line.

I'll have a look at needles as I have read before that the stage 1 kit needles aren't very good for mpg. I'll syphon out the old fuel and put some new in to see if that helps. Thank you! 

Edited by WillCarter, 05 July 2016 - 09:52 AM.

[WillCarter]

One more thing, if I ever get all the problems sorted, is there an optimum idle speed? 

[ukcooper]

if its running rich it be using more petrol, id just spend the money on a r/road sesson as they set everything up including the needle . of the shelf needles ae never fully correct I believe.

 

But if you ever change any thing lke a standard air fillter to a k'n then it needs another r/road sesson .

[WillCarter]

I did a rolling road session a while back and it ran okay after that but since it's been parked up for about 2 months it's started to back fire. 

[WillCarter]

Also where's the best place to put a fuel filter? 

[Dusky]

 

 

the engine's never really been tuned properly 

 

So would you recommend adjusting the ignition timing first? 

 

Depends where it is now.
Honestly : Go to a garage, ask them to set the ignition timing at 8-10° advanced
Then connect the car to a CO meter and set the CO to 2.5-3.5% at idle. Keep the needle that came with the kit.

The car will drive better than it ever did.

Fuel filter just after the tank here.

Edited by Dusky, 05 July 2016 - 10:19 AM.

[WillCarter]

 

 

 

the engine's never really been tuned properly 

 

So would you recommend adjusting the ignition timing first? 

 

Depends where it is now.
Honestly : Go to a garage, ask them to set the ignition timing at 8-10° advanced
Then connect the car to a CO meter and set the CO to 2.5-3.5% at idle. Keep the needle that came with the kit.

The car will drive better than it ever did.

Fuel filter just after the tank here.

 

Great, thanks very much!

[gazza82]

Depends what pump you have but it should be between pump and carb.

 

If it's mechanical and on the back of the engine it should really go between that and the carb inlet pipe.

 

If you have an electric pump, still between pump and carb but you have more places to fit it .. some fit these just after the pump outlet, but then they are a pita to check replace.

[WillCarter]

The car won't even start now.

[WillCarter]

Took the carb off and cleaned everything, the car still won't start and now the jet's stuck so the choke won't pull out, seriously losing my mind with this blasted car. 

[Dusky]

Why did you take the carb off to clean? 
Your jet will need centering again probably.