700 double pumper on a road car

[GJUK]

All I ever do is adjust the pump arm just a smidge past zero clearance, and then hold the throttle wide open and press down on the pump arm to check there's some movement left, that's it. Pump delivery is controlled by the pump cam, set up my way you must get as big a shot as is possible with any given cam.

My arm had no movement at all left in it after full open throttle, maybe I need to back it off a bit. I know this can damage the thin rubber seal if stretched over.

Would you agree with the above John?

Thanks.

[Blue]

Yes it can, or rupture the diaphragm. If it's done either you'll have no pump shot. Back the adjustment right the way off till it's floppy, then tighten back up again until there's only just no play, give it maybe 1/4 turn more and call it done.

[GJUK]

Yes it can, or rupture the diaphragm. If it's done either you'll have no pump shot. Back the adjustment right the way off till it's floppy, then tighten back up again until there's only just no play, give it maybe 1/4 turn more and call it done.

That is exactly how i set it up.

At full throttle however this is no more movement in the diaphragm

[GJUK]

Well, everyone can now call me Mr Carb.

I got home today and fitted my temperature sender ((which works) thanks Blue)) and fired up the car.

Warmed up, it still had a light pop.

I'd read somewhere that its a sign of the car being retarded, even though it is running 17* of advance at idle!

So I spun the dizzy advancing it, revs raised, up up up and I turned the bloody thing about 8mm before it started to feel rougher.

The car revved clean then.

Out on a test drive of about 2 miles and it pulled like a train.

No flooding (float issue)
Slight drop in power between 1200 and 1800 rpm but no bog at all, this is very slight and i can try to tweak it.

Very pleased. Thanks for all your help guys!!!!!!!!!!!!!

Jon

[MilesnMiles]

Sweet. 20 pages and success

[Mick]

I bet you glad you stuck with it now Jon.
Just be careful not to over advance it, do a bit of driving and then pull a plug and if you see little black flecks on the porcelain, then back it off a couple of degrees.
Mick

[GJUK]

Sweet. 20 pages and success

I bet you glad you stuck with it now Jon.
Just be careful not to over advance it, do a bit of driving and then pull a plug and if you see little black flecks on the porcelain, then back it off a couple of degrees.
Mick

Thanks for the advice.Glad its running well yeah.

I will try and find out where the timing is at right now, its still needs tweaking, just not as much as before.

It's probably about 23* at idle nearly 40 at full advance.

Jon

[Mick]

Go one to the left.

[Mossy68]

Great news Jon.
Think I'd be tempted to get the timing bang on before I fiddled with the carb anymore.

[GJUK]

Go one to the left.

Cheers mate!

[GJUK]

Great news Jon.
Think I'd be tempted to get the timing bang on before I fiddled with the carb anymore.

Yeah, its just done by ear though at the moment.

17 degrees of advance at idle SHOULD have been spot on.

[Mossy68]

Great news Jon.
Think I'd be tempted to get the timing bang on before I fiddled with the carb anymore.

Yeah, its just done by ear though at the moment.

17 degrees of advance at idle SHOULD have been spot on.

I'm still learning myself , and by ear is sometimes the way to go.
Plenty of info on timing on here as you know. From what I've learned each engine seems to have its own " sweet " spot at idle. Once you've got that start looking at your total , around 34 degrees. ( sorry. Like me you've probably already stored this info in your brain )

[GJUK]

I will get a timing light on it at some point, at the moment it runs well so no panic

[Mossy68]

I will get a timing light on it at some point, at the moment it runs well so no panic

Get out and make some noise before the weather turns !!!

[Cannonball]

watch street outlaws you will chuck that 700 double pumper in the bin,,,,