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Engine dies with any attempt at throttle

Posted: Thu Apr 26, 2012 7:03 pm
by capnblack
Just put engine back in after renewing clutch. While engine was out I fitted a spin on oil filter conversion (the first of which had a hole through the casting so spewed oil out - ESM replaced FOC),also fitted new water pump, thermostat, water elbow, points, plugs & condenser, new throttle cable etc. Now the engine will start on choke but any attempt to rev engine results in it dying unless choke is right out. Most frustrating. Ideas please?

Re: Engine dies with any attempt at throttle

Posted: Thu Apr 26, 2012 7:16 pm
by simmitc
Blocked jet? Piston in carb stuck? Something in the distributer - that's where you changed things. The clutch and the oil filter won't make any difference!

Re: Engine dies with any attempt at throttle

Posted: Thu Apr 26, 2012 7:18 pm
by moggiethouable
Do forgive me for this, but is the throttle cable passed through its associated Ferrule pin? before fitting it to the throttle linkage? :wink:

Re: Engine dies with any attempt at throttle

Posted: Thu Apr 26, 2012 7:24 pm
by capnblack
Yep, cable passes thro ferrule pin above it before connecting to throttle linkage. I was wondering if it could be due to the choke cable attachment / adjustment being different now that things are reconnected, the reason I say this is because, if the choke is right out, then application of throttle does increase revs. Most strange.

Re: Engine dies with any attempt at throttle

Posted: Thu Apr 26, 2012 7:41 pm
by bmcecosse
You've changed so many things- you will need to just work through everything from scratch - ignition timing and carb settings. At least it runs - get it warm and then set it up!

Re: Engine dies with any attempt at throttle

Posted: Thu Apr 26, 2012 10:30 pm
by chrisryder
is there oil in the dashpot?

when we bought our latest minor, it had the big air filter over the top of the dash pot, which meant nobody had bothered to go to the effort of taking it off to get any oil in there.

engine had the same symptoms until i put fresh oil in the dash pot and it was fine then.

If there's nothing to 'damp' the piston, any touch of the throttle will make it fly up, and go way too rich, and die.

Re: Engine dies with any attempt at throttle

Posted: Thu Apr 26, 2012 10:44 pm
by bmcecosse
Way too weak.....not rich

Re: Engine dies with any attempt at throttle

Posted: Fri Apr 27, 2012 8:56 pm
by capnblack
I have the engine running lovely ........ Without any load. I think that the choke cable may have been applying choke before the knob was pulled out prior to the engine being out-in. I have screwed out the adjustment beneath the carb to enrich the mix, BUT .. When I drive the van, the throttle depressed, the engine coughs and splutters. Runs slightly better if the choke is pulled.

I tried the "suck the vacuum advance tube" trick with the dizzy cap off - there is no apparent movement of the base plate in the dizzy. Also, the vernier adjustment on the dizzy is at th end of the advanced scale.

Considering a new distributor.

Re: Engine dies with any attempt at throttle

Posted: Fri Apr 27, 2012 9:08 pm
by bmcecosse
Ah well - the vac advance is knackered....yes a new 45D dizzy from simonbbc is probably the best bet!

Re: Engine dies with any attempt at throttle

Posted: Fri Apr 27, 2012 9:12 pm
by capnblack
Are we taking new distributor with points or electronic ignition?

Re: Engine dies with any attempt at throttle

Posted: Fri Apr 27, 2012 9:14 pm
by bmcecosse
Your choice - I would go with points - but the leccy unit seems to work well enough going by the reports.

Re: Engine dies with any attempt at throttle

Posted: Fri Apr 27, 2012 9:19 pm
by capnblack
Just been looking. I fancy keeping traditional. Points. My pickup is positive earth, I'll get in touch with Powerspark (simonbbc) and see what they advise.

Re: Engine dies with any attempt at throttle

Posted: Sat Apr 28, 2012 6:30 pm
by capnblack
OK.
Changed the distributor for one I had on an engine which is destined for my Postal Engineering van - no better. Changed the carb for the one off the van engine. That's it!
Can't understand what's happened to the carb off Lilly. I did check the usual in Lilly's carb before pinching the one off the van.
Anyway, seems to be running well now with new clutch etc.
Another mystery.
Thanks for your suggestions.

Re: Engine dies with any attempt at throttle

Posted: Sat Apr 28, 2012 7:29 pm
by bmcecosse
You said the vacuum unit didn't move - does it move on the 'new' dizzy - or is it knackered too?

Re: Engine dies with any attempt at throttle

Posted: Sat Apr 28, 2012 8:11 pm
by simmitc
I go back to my first reply - blocked jet or stuck piston in carb! I also agree with Roy in that you need ot resolve the vacuum problem as well.

Re: Engine dies with any attempt at throttle

Posted: Sun Apr 29, 2012 9:32 am
by MarkyB
If you take the carb off but don't keep it upright, silt from the bottom of the float chamber can find it's way into the jet tube and blocking it, partially or fully.

Re: Engine dies with any attempt at throttle

Posted: Sun Apr 29, 2012 2:13 pm
by capnblack
The vacuum advance works on the "new" distributor.
Checked the float chamber, jet & piston in the old carb b4 replacing it.

Re: Engine dies with any attempt at throttle

Posted: Tue May 08, 2012 9:25 am
by capnblack
Sorted.
Rebuilt the original carb with SU rebuild kit from ESM.
Now running like a sewing machine once more.
Thanks for all your input, appreciated.