rat256
Ahh! Just passed their bike test
Posts: 24
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Post by rat256 on Mar 27, 2010 0:58:07 GMT 1
Right, a little history first.
last year I got a puncture in the rear tyre, the bike then sat out the back of my work for the rest of the year. I've just got it MOT'd and insured again and started riding it.
I did about 50 miles on it last week and had problems with it dropping a cylinder, but it always came back if I gave it some more revs, earlier today it dropped onto one cylinder and I couldn't get it to come back so this evening I have stripped the carbs and cleaned them out... let me tell you I have never seen so much crap in the carbs of an engine that still ran, albeit badly! However the cleanout has worked and I have full power back again.
however...
it now won't idle for toffee, the revs sit at about 1400 rpm and don't drop. the idle screw is wound all the way out, the choke, as far as I can tell, is off, there is slack in the throttle cable and the throttle cam is all the way home, yet it sits at 1400 rpm. I'm going to piss off my neighbours if I try to fix it now, but does anyone have any more suggestions for tomorrow?
air idle screws?
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Post by rj2para (Bisto) on Mar 27, 2010 7:33:47 GMT 1
Cant't help personally but this will make it stand out as today's post. Good luck.
Roger
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Post by McF on Mar 27, 2010 9:36:51 GMT 1
That's odd!
Did you clean all of the jets through with compressed air? If you had as much crud as you describe, it can get everywhere, but I'd be surprised if a blocked jet caused an increase in idle speed.
It sounds as though you have done the next obvious thing and have the idle screw all of the way out with the plate now pressing on the lug where the idle screw is fitted?
So next I'd check that everything is fitted and routed correctly, especially the choke cables and where they fit into the carbs, are their springs etc all doing the right thing?
The choke cable splits so I would also have a look at the cable and run all the way from the handlebars.
Does the choke make any difference to the idle speed? Probably only able to confirm this when the engine is cold. Get her started with full choke and as soon as you can, close choke and see if engine revs drop.
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rat256
Ahh! Just passed their bike test
Posts: 24
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Post by rat256 on Mar 27, 2010 11:49:57 GMT 1
yes, cleaned out with tons and tons of compressed air... but i'm going to whip the choke cables off again and have a blast down those just to make sure there is nothing blocking the choke airways.
the idle adjuster is backed off all the way, flush with the plate, and the cable cam is sat with it's stop hard against the plate, It won't go any further!
as it only takes me about 20 minutes these days, I'm going to swap a spare set of carbs in and see if they work, it's quicker than trying to muck about with the air idle screw settings!
any further input greatly appreciated
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rat256
Ahh! Just passed their bike test
Posts: 24
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Post by rat256 on Mar 27, 2010 16:41:56 GMT 1
Ok, Panic over.
I've fixed it... swapped in spare carbs... same result... finger of blame swung towards sticky choke cable
swapped in choke cable from the Bros. doesn't seem to work as a choke, but it plugs the holes and it all idles evenly again.
I can get to work OK which is the main thing, and in the mean time I'll order a new choke cable from david silvers.
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Post by Buzzin (^_^) on Mar 28, 2010 9:52:04 GMT 1
Check the choke cable: mine had a problem with the outer sleeve being too far out of the 'splitter' Pop it back in and it works once...or twice before it pops out again... My solution: pinch the splitter around the cable a bit so the sleeve can't pop out. Works fine to this day  Also, make sure the springs at the end still work... |
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rat256
Ahh! Just passed their bike test
Posts: 24
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Post by rat256 on Mar 28, 2010 17:47:56 GMT 1
Choke cable was the problem!
What was happening was the choke lever pulled the cables taught and engaged the enrichment circuit, but when you tried to close the choke one of the cables out of the split was a bit tight.
If you look in the manual it says that the distance between the plastic nut and the start of the choke valve should be 10-11mm apart, when i measured it one bang on the money, the other was only about 6mm thus suggesting the enrichment circuit wasn't disengaging. lubing the cables and trying to straighten the the kink out only gained a mil of return, so a swap of cables ensued. as soon as the new cables were in it all worked like a charm.
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Post by McF on Mar 28, 2010 19:05:34 GMT 1
Glad you got the diagnosis sorted and the problem solved
Happy riding
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Post by Buzzin (^_^) on Mar 29, 2010 18:34:06 GMT 1
Glad that is sorted.....hope you have fun riding |
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