1500 engine wont go above 4500 rpm

Aug 13, 2003 11 Replies

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Minime 22 years ago

Hi!

Could anyone help me with this? I finished my Midget 1978 but it wont go above the

4500 rpm! it has everything: a good ignition system, Weber carburettor conversion, amd it even sounds great! up to 4500 rpm, it runs smooth, but if i want to go above that, it loses power like if it did not had enough gasoline or something.

My mechanic suggests that we open the engine, clean it entirely, put clean oil and new gaskets and a "Prolong" treatment. or maybe it needs an additional fuel pump? (it only has the mechanic one)

Does anybody agrees/disagrees? i know its not enough information, but any feedback will be very appreciated.

Thanks! Michael

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John Manders 22 years ago

Check the auto advance on the ignition timing.

John

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Minime 22 years ago

Thanks, Joe! I will check that with an electrician.

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Graeme 22 years ago

Well he would, wouldn't he.

I cant say what the problem is but it doesn't need an additional fuel pump. If the original is working it will be pumping enough fuel. If its not, fix it or replace it maybe with an aftermarket one. But additional, just not needed.

It is fuel or electrical, probably electrical.

What opening the engine and cleaning it will do is beyond me.

Graeme

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James Mather 22 years ago

Is it just under load it falters or will it rev freely in neutral? Will it for example go faster down hill? If you build up speed to as fast as it will go, then release the throttle for 10 secs or so, it will give float bowls time to fill up. If it then goes better but then dies, it is fuel starvation. Hasve you checked that ther is no air lock in fuel tank. Try it with no fuel cap on. Air lock probs worse when fuel tank is full.

JSM

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James Mather 22 years ago

I assume that the cam timing is OK and that it is not fitted a tooth out. Worth checking. Can prob be done with just rocker cover off and with a DTIndicator James

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steve-s 22 years ago

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Mike Mnemonic 22 years ago

Also check that the distributor drive has been fitted correctly. I have suffered from both this fault and the incorrect cam / crank timing due to previous owners. In both cases, the engine ran OK-ish at low speed.

Mike Mnemonic

68 & 72 Midget

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Minime 22 years ago

No, even downhill it will have trouble when passing 4500 rpm.

i will check that also, thanks!! :)

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Minime 22 years ago

Thanks for the feedback! Michael

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Dave Baker 22 years ago

Check that you do not have any broken or faulty valve springs.

Dave Baker - Puma Race Engines

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Minime 22 years ago

hmmm...you made me think. this engine can deliver more power than we commonly think...

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