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Author: Subject: Unhappy engine
Rob Palin

posted on 14/8/03 at 07:19 PM Reply With Quote
Unhappy engine

My engine's not been itself since we went to Pembrey. I can only just about coax it over 6000rpm in first and second gear and in third or fourth it just runs out of puff at 6k.

Also if i try to go over 6000 in second it sort of gurgles a bit and loses power. Please can anyone give me any opinions about whether this is a carburettor or timing/ignition or some other issue?

The only thing i changed between Cadwell and Pembrey was the radiator (which got crushed at Cadwell and replaced with an identical one with one repair on it and no sign of radweld) but surely a slightly higher load for the water pump couldn't do this - could it?

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DickieB

posted on 15/8/03 at 11:19 AM Reply With Quote
Rob
I had no idea - so went for the phone a friend option! This is what he suggested (verbatim!):

When I hear of things like this I revert to my father's checklist: "To get an engine running you need four things: fuel, air, compression and a spark"

Clearly they are all available but not at high rpm.

Under those headings I'd do the following checks:

Fuel
Disconnect fuel pipe to carb and (assuming electric fuel pump) switch ignition on with fuel pipe filling a milk bottle or measuring jug. For a period of exactly 30 secs how much fuel comes through? You should have about (ISTR) half a pint per brake horse power per hour. So for 80 bhp and 30 secs about 2/3rds of a pint.

Is the carb bowl full of muck?

Is the fuel filter clogged with muck?

Air
Is the filter full of dirt?

Has the throttle cable adjuster become dislodged?

Is full open throttle being achieved?

Compression
Do a compression test

Spark
What ignition system is in use? If clockwork, remove the condenser and run it briefly to test
Check the cam:crank timing. Was it left in gear on the trailer? This can allegedly (though I'm not convinced) cause a back drive jolt that can jump a slack chain by one tooth.

If none of the above then the only option is a trip to the rolling road....

One thing to remember is, just because it hasn't run since Pembrey doesn't mean it hasn't been subjected to x hundred miles of vibration whilst on the trailer. I'd be amazed if a clogged rad could load the water pump up so heavily: the belt is only capable of transmitting a few hp before slipping and screaming.

Hope this helps
Dickie B
Locost 71
http://www.TeamDickie.co.uk

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Rob Palin

posted on 15/8/03 at 03:49 PM Reply With Quote
Hi Dickie,

Thanks for the advice, i'll go away and check those things over the weekend.

Its funny that it was actually chasing you around Mallory Park last Sunday that's prompted this because it drew my attention to my lack of straight-line speed. My set-up was working brilliantly in the wet but you'd just pull away along the straights.

I know i'm not normally within a country mile of you on track so its more that i've seen the qualifying arrangements for Silverstone and i think i'll need every bhp i can get to make sure i get into the race at all!

Thanks again for your help.

Rob

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steve26

posted on 18/8/03 at 12:59 PM Reply With Quote
Hi dickieB, - you have a U2U.

[Edited on 18/8/03 by steve26]






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DickieB

posted on 18/8/03 at 03:55 PM Reply With Quote
Dan
You have a U2U too - never tried that before!
Dickie

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Rob Palin

posted on 18/8/03 at 06:45 PM Reply With Quote
Dickie - i checked the various things on your list and i think it could be just that the air filter's got clogged and the carb's then become a bit manky inside.

I've cleaned the filter but it still seems quite restrictive (the intake wheezes when you floor it) so i'm going to try to get a bigger one.

Also i'll try to get it to a rolling road in between Silverstone and Cadwell. I can't afford to go to Lydden so i'll use that month gap to try to sort it out. Thanks for your help.

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DickieB

posted on 19/8/03 at 09:07 AM Reply With Quote
Rob
No worries. Now don't you go beating me!!!!!!!
Dickie B

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Rob Palin

posted on 19/8/03 at 06:34 PM Reply With Quote
Nah, unless i hitch a ride on a flying pig i don't think i'll be getting ahead of you anytime soon!
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