mistergrumpy
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| posted on 24/7/08 at 04:16 PM |
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Well I've been messing with the damned thing again. I've tried needle settings at 2,3, and 4 with mixture screw from 1.5 turned in
quarters up to 3 turns and it still won't play. 
It's being a bitch to start. Having to give it full choke and just keep it turning over for about 15-20 seconds before it'll go then it
idles fine. The problem seems to be that when I rev it slowly, at the very point that fuel comes out of the main jet, the engine stalls. There also
seems to be alot of fuel coming out of the jet when I'm trying to start it and it'll happily splash me in the eye when it stalls. Any more
ideas. I'm beginning to loath this sodding engine. There's very little fun left in this build
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locosaki
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| posted on 24/7/08 at 05:44 PM |
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This is just a stab in the dark,I don't think you should be getting fuel from the main jet when you are trying to start it,Are you sure the
needle in the float chamber is shutting when the fuel level is reached,also have you checked the float levels ??
Are you using the orginal bike fuel pump (maybe to much fuel pressure)
Might also be worth checking the diaphragm in the top of the carbs (make sure there not split etc)
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mistergrumpy
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| posted on 24/7/08 at 06:20 PM |
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I'm not sure if I should be getting fuel through the main jets also so I'll check them tomorrow. Yes I'm using standard fuel
pump.
I read somewhere:
idle = mixture screw
mid range = needle
top end = jet size
So I was thinking needle height but I suppose if the jet is wrong then it can impose on the needles job. I'm all confused now 
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locosaki
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| posted on 24/7/08 at 06:31 PM |
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your mixture screw sets up low down rpm as per Si's post,the needle is mid range,I'm refering to the needle that is attached to the
floats,when the floats reach the desired height the needle on the tang at the end should shut the fuel supply off.I don't think the size of the
main jets will make any odds at this stage mate.Are you getting fuel coming out of the 4 mains at tick over or just 1 ??
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mistergrumpy
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| posted on 24/7/08 at 06:48 PM |
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Erm, I'm getting no fuel coming out of the jet at tick over.
It only comes out at start up, when I press the throttle, at which point it stalls and fuel tends to come out once the engine has stalled, quite a lot
actually, just dribbles out.
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simoto
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| posted on 25/7/08 at 09:15 AM |
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Hang on let me have a read through, be with you in a minute.
striker/blade now complete, thanks to all on this site.
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simoto
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| posted on 25/7/08 at 09:24 AM |
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Sounds like float level or seal problem at the moment and without seeing im a bit stuck myself.
I will u2u my tel no to you in case thats helpful.
Def shouldnt have weeping fuel from main jet and that is very indicative of float malfunction if its welling up as such.
Most of these carbs were designed to be gravity fed and even a low pressure pump can be a problem with internal seals being affected typically.
Sorry so long again im just back to work after long absence and very busy.
See u2u. regards
si
striker/blade now complete, thanks to all on this site.
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mistergrumpy
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| posted on 25/7/08 at 11:17 AM |
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Si. No apology needed mate I'm just really grateful that you're taking time to help.
Locosaki. Help appreciated also. I'll crack on with stripping them again and update later.
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simoto
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| posted on 25/7/08 at 01:26 PM |
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I'm stuck between a seal issue and a possible mistake on reasembly(to include float level). Gurgling eh?
Was the ignition on/pump powered up at the time?
If not could be seals relinquishing the pump pressure, or slow recovery of slide diaghtams related to the drilling(obscure that)
I have seen these engines fill to the brim with gallons of fuel due to seal and float issues so please be careful and check your fuel isnt disapearing
in large quantities and ensure a fire extinguisher is at least around and/or well ventilated area. Honestly, if your in a closed room breathing petrol
fumes for more than about five minutes you will do well to identify your own family never mind a carb problem. Safety first. Feel free to ring me.
Pretty convinced that the slide drilling has been made a horlix of(sorry/blush) upside being its relativelly easy though poss pricey to sort.
A spare set of carbs would be real handy right now especially if near to you. As yet mine are an unknown quantity too so far from ideal for the
purpose.
Anyone?
Good luck. Si
striker/blade now complete, thanks to all on this site.
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mistergrumpy
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| posted on 25/7/08 at 04:09 PM |
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Well. Thanks to the advice given I set about stripping the carbs down again and giving them a real good clean. Took ages at it as I was feeling crap
after having a wisdom tooth out earlier (nearly passed out at 3rd carb  ) Anyhow one of the carbs had a slight jelly mix in it but what I did find
that I didn't do last time is that around the breather hole that gets blocked off, there are 3 or 4 other holes and these were filthy. I just
squirted them with cleaner till it came back out clean.
Re assembled it and started it up and......
fired first time Me and the neighbour were grinning like Cheshire cats. There's a very slight hesitancy around 2000rpm and the carbs
still sound a bit lumpy but I'm going to balance them tonight or tomorrow. Over the moon though.
Thanks for all the advice given and U2U's it's massively appreciated
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locosaki
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| posted on 25/7/08 at 04:41 PM |
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Good to hear your getting on better now mate,Hopefully now it'll just be a case of trying different needle position and mains untill you get the
desired effect  !!
I have been at mine all afternoon and now have it running near perfect,My problem (I'm assuming) Is my main jet has been way to big,I started
with a 170 mian and I'm now down too a 140 main and it's going without any spluttering 
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mistergrumpy
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| posted on 25/7/08 at 04:48 PM |
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So 2 successes in a day eh Great
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simoto
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| posted on 25/7/08 at 10:39 PM |
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Yay superb lads, there a doddle when you understand em. Just a trial kto keep taking them apart and requiring patience to be systematic.
Bloody well done again and if i was any help to either of you then im totally made up
Regards si.
striker/blade now complete, thanks to all on this site.
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locosaki
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| posted on 25/7/08 at 11:59 PM |
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Si mate,
Hats off to you,you have took the time to answer us with our problems and have helped me no end understand these carbs.
Thanks again,much appreciated
Mike
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mistergrumpy
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| posted on 26/7/08 at 03:44 PM |
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Again and as above mate. Superb. Thanks for taking the time.
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