Engine Not Firing Properly After Heavy Acceleration

[Guest christcp2]

I have a pinto engine with twin webers. It runs quite well under light acceleration but after heavy acceleration the engine and exhaust start to feel like they are being choked. This get steadily worse until the engine loses all power and needs to be left for an hour to recover. Could anyone suggest what might be causing this please? Would air leaks in th exhaust cause this?

[Guest 2b cruising]

Defoe not air leak in exhaust. Only thing I can think of with exhaust would be over stuffed silencer or collapsed stuffing in silencer.

If you can take your plugs out after it stops, check what colour they are. If black and sooty, you are overfilling.

If they are very light coloured, you are to week.

If either of these two things are apparent, unless you know about carb setting don't fiddle with them.

Check your fuel filter is clear. Check your pick up pipe in the tank is not drawing air instead of fuel.

If there is a strong smell off petrol, or wetness around carb tops, your float level could be out.

Is your choke sticking on. This is one cause of black plugs.

Test fuel pump for sufficient output. If bad output check fuel feed to it first, before condemning pump.

Has it been stood for a long time. Petrol goes off after long stagnant periods and should be changed along with fuel filter.

 

These are just a few thing it is possible to self check. If the problem cannot be found, I would recommend take to specialist with a rolling road for optimum settings to suit your engine and ignition system.

HTH. Regards, Ken.

[Bob Tucker]

Check the tank is vented properly.

[Guest 2b cruising]

Forgot about that one Bob. Quite common fault to. Have you ever seen a collapsed tank?

[Bob Tucker]

No.....but weve had a few cases in the club where

the tank itself isnt vented & the cap is airtight.

 

Chris, next time it happens, open the tank filler cap & listen for a hiss.

[cb750]

Agree, check that tank is venting OK. Had same problem with collapsed gasket on a motorcycle tank filler cap blocking vent which gave the same symptoms.

[Guest christcp2]

Thanks for the help. I'll take it out next weekend and check for the hissing.