Club 80-90 Forums

tamson wrote: Ok just got in from tweaking the carbs to basic setting. Fired up and was running sweet idling at 850rpm. However when I turned the engine off then started it again the revs dropped to 650. The only difference I noticed was that there was no air sucking through the pipe on the top of the left carb. Also screwing the idle screw in and out made no difference to the rpms's. Any ideas? Cheers

I think i've sussed that the idle bypass solenoid might have broke. Annoying as I only bought it a few months ago. I tested it by unplugging it and removing it from the carb, then with ignition on. touched the terminal with the spade connector. No click. Am I right in thinking that it should retract, allowin air through when the ignition is on then closing when ignition is off to prevent engine run on?

I'm not certain of this but I don't think it will click if it's not earthed. I know you can check for the click in situ by disconnecting and reconnecting the spade connector with the ignition on but the engine not running. If you try the same with it unscrewed from the carb I don't think there'll be a circuit. Try holding the solenoid against the engine casing and connecting the spade connector.

I tested it again using my 12v power pack. I gripped the spade connector with the positive and earthed it by gripping the body of the cut off valve with the negative. It worked but only when I pushed the valve in slightly. So I tried it in situ in the carb again, plugged and unplugged it half a dozen times and I heard it click, on a couple of these attempts. I just installed a new idle stabilization unit the other day and thought that could be shorting it out or maybe I had a bad earth or something but all the other devices like fuel cut off valve and chokes work fine. Think ill just bight the bullet and buy a new one!

Yep problem solved. Got new one from GSF, made by Brosol.

BOXY wrote:Have you got the vac lines going to the right sides on the dizzie. Easy to get them wrong if they've been off.

Here's the whole sordid story.

https://club8090.co.uk/forum/viewtopic.php?f=39&t=79992" onclick="window.open(this.href);return false;

Hi Boxy Ive been checkin out that link you posted RE the vacuum hose connections. Layout differs slightly from mine. Do you know where the retard port on the right carb (pdsit 3) is wired to in the pictured layout? I cant make out where it would be connected. Mine is connected directly to the retard port on my dizzy. Cheers.

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There isn't a connection to the right-hand carb, it should be blanked off. The vac pipe labelled 4 goes to the valve on the main air inlet pipe to the airbox.

Thats interesting, so should I blank mine off then and if so what should I use? I always thought it was strange that I only had one pipe connected to the front of air box.

The stub pipe on my right-hand carb has got a factory fitted rubber cap over it.

Hi Folks,
Just going back to this subject, mine is showing 18 btdc at idle and running sweet as a nut.
if i move to 6btdc it runs like crap!
Can i leave it well alone and be happy or will it blow up?

jc

It should be 6' ATDC so if you're running at 18' BTDC at idle in theory at higher revs you could be running at over 60' BTDC. If you were really running that far advanced your engine would probably be running backwards? See if you can borrow another timing light and check the timing scale is in the right place.

BOXY wrote:It should be 6' ATDC so if you're running at 18' BTDC at idle in theory at higher revs you could be running at over 60' BTDC. If you were really running that far advanced your engine would probably be running backwards? See if you can borrow another timing light and check the timing scale is in the right place.

All ready on it Boxy