Author Topic: Running rich  (Read 1374 times)

Offline martyn1061

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Running rich
« on: December 15, 2021, 10:42:47 AM »
Hi
Just overhauled carbs, started up and motorcycle running very rich. Any ideas how to adjust mixture strength.
Thanks

Offline taysidedragon

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Re: Running rich
« Reply #1 on: December 15, 2021, 11:03:56 AM »
Check float levels, make sure choke is fully off when lever moved (it may need adjusting) and set airscrews about 1 and a half to 2 turns out from fully in.
Gareth

1977 CB400F
1965 T100SS

Offline martyn1061

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Re: Running rich
« Reply #2 on: December 15, 2021, 11:13:34 AM »
Hi Gareth
Thanks for that, i have done that, I have even adjusted the air screws out 2.5 turns to weaken it further but still running rich.
Unless I re-strip the carbs and recheck float heights.
Martyn

Offline McCabe-Thiele (Ted)

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Re: Running rich
« Reply #3 on: December 15, 2021, 11:46:19 AM »
I'm a novice here - my first question is are the compressions good - does it fire up from cold easily? Do you have standard a air filter arrangement. If the answer is yes to all I would re-check float levels & needle positions - are the carb floats, needles original or good quality replacements?
Honda CB400NA Superdream (current money puddle)
Honda CB500 K1 (second money pit)
https://www.sohc.co.uk/index.php/topic,28541.0.html
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
This is a neat 500 restoration in the USA.
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

Offline Dave

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Re: Running rich
« Reply #4 on: December 15, 2021, 02:46:35 PM »
If running a standard carb setup, check under the seat. Is the air intake blocked / restricted?

Dave

Offline martyn1061

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Re: Running rich
« Reply #5 on: December 15, 2021, 03:26:11 PM »
I'm running single filters, compression good, all new jets etc. I have removed the carbs again now so i will re check float levels.

Offline Bryanj

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Re: Running rich
« Reply #6 on: December 15, 2021, 03:53:21 PM »
Put the original jets back in, aftermarket are notoriously innacurate

Offline K2-K6

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Re: Running rich
« Reply #7 on: December 15, 2021, 03:54:10 PM »
Presumably a 400 four ?

You'll probably need to tell us what jets are in there to get more considered view and input.

Individual filters can be difficult (but not impossible) to get a consistent setup, but with some baseline settings that look odd to the std factory baseline.

Offline martyn1061

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Re: Running rich
« Reply #8 on: December 15, 2021, 04:50:18 PM »
Hi
As i have got the carbs back out i will put the original jets back in and recheck float heights

 

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