Author Topic: New to the forum  (Read 812 times)

Offline Harriec

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Re: New to the forum
« Reply #15 on: March 28, 2024, 07:21:48 PM »
So I took the rubbers off and they were all ok (in fact they look brand new). I do think they may not have been seated properly. To be honest I think I've been dealing with more than one issue.

So with those things sorted...it now runs well. It starts in the button and chokes all good. It gets warm and I have it idling nicely at about 1500rpm but as soon as I throttle it gets stuck at around 3000rpm then if I leave it it will come back down and eventually cut out. I constantly have to choke or change the idle. I'm pretty sure it's not sticky carbs as I had them out and they looked good. And the cables are aok. I replaced and set them up myself. Any ideas what else it could be?

Sorry for all the questions...you've all been very helpful!

Offline K2-K6

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Re: New to the forum
« Reply #16 on: March 28, 2024, 07:53:38 PM »
Some considerations.

The throttle cables need to have a prescribed amount of slack, usually the "pull" one is adjusted only. A rudimentary test is to turn steering from lock to lock and blip throttle (while running) at each extreme .... any change at either end, then it needs more room to play with. I can get the spec from manual at twistgrip if you need it.

There's concise method to setup idle circuit jetting if they're been apart before, that's in manual, to get them on aim for mixture. This can get them "hanging " as described if not fully understood and implemented.

Choke should give up to about 2,750 rpm fully out, but obviously when fully home shouldn't be lifting the throttle slides at all. Also data in manual to set that correctly.

Offline Harriec

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Re: New to the forum
« Reply #17 on: March 28, 2024, 08:04:13 PM »
Thanks for this. I will test the throttle tomorrow and start there. I'll also look into the idle circuit set up...

Offline Bryanj

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Re: New to the forum
« Reply #18 on: March 28, 2024, 10:09:16 PM »
As to choke the F2 is very "cold blooded" and takes quite a while before it will run off choke, again the pilot ways are notorious for clogging

Offline ozzybud

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Re: New to the forum
« Reply #19 on: March 28, 2024, 10:39:18 PM »
Welcome to the forum
1976 Z50 YELLOW
1970 CT70 BLUE
1971 CT70H ORANGE
1972 CT70H GREEN
1973 CL200 BLUE
1975 CB360T RED
1975 CB400F BLUE
1975 CB550 ORANGE
1976 CB750F RED

Offline K2-K6

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Re: New to the forum
« Reply #20 on: March 29, 2024, 11:08:56 AM »
Thanks for this. I will test the throttle tomorrow and start there. I'll also look into the idle circuit set up...

They are similar to your garden machinery in some effect. The adjustment screw on these carb is engine side of throttle slide and controls fuel (unlike predecessor, with air adjustment) winding out/unscrewing should bring more fuel to low speed.

Changing each one in isolation should bring about obvious shift in running for that cylinder, no response suggests impairment as way of assessment.

The aim in Honda setup routine is to bring them to borderline lean point to give combustion reference, then lift the mixture a little toward richer ( they indicate  100 rpm drop from that richer state) to get them as good for further evaluation. 

If left too lean on this circuit, that forces you to then run the slides lower than ideal in controlling the tickover aim point. That can give some of the inconsistencies you've currently got.

 

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