SOHC.co.uk Forums > CB350/400

CB350F poor starter runs irratically

<< < (3/3)

Budgie955:
Great idea I tried it , killed it stone dead . I'm convinced it's over fuelling, because it won't have it on full choke. I've played around with float height and had it running on all 4 , but rough.
Carb kits ordered so let's see when they're installed
Cheers guys

Mikep328:
Don't know what type of floats were used on the 350 carbs (foam, hollow plastic, hollow brass, etc) but I can say that non-floating floats are not unusual.  Plastic/brass floats are pretty easy to tell - is there fuel inside or cracks/pinholes?  Foam floats, OTOH, look the same whether they float properly or not.  Some particular foam floats were known to lose buoyancy over time as they slowly absorbed fuel and it was considered "normal" to replace the factory floats after not all that much time.

The normal float level procedure does not account for floats that do not have their original buoyancy.  Consequently, they can be set perfectly but fail to shut off the fuel at the proper point.

Skoti:

--- Quote from: Budgie955 on August 01, 2026, 09:42:40 PM ---Great idea I tried it , killed it stone dead . I'm convinced it's over fuelling, because it won't have it on full choke. I've played around with float height and had it running on all 4 , but rough.
Carb kits ordered so let's see when they're installed
Cheers guys

--- End quote ---

Make sure the kit includes new slide needles and needle jets, because those are the bits that most often wear resulting in over rich mixture.
Plus another symptom of the wear is cold starting without needing choke.

Athame57:
I had a problem like this on a Suzuki GT380, in the end all I had to do was get new plug caps.

Otis:

--- Quote from: Budgie955 on August 01, 2026, 12:01:38 PM ---Timing is spot on
I've fitted new inlet rubbers and it's the same 1 and 2 running . 3 and 4 warm not hot
I pulled out no4 plug today and it runs on all 3   so no 4 is pulling it down . Carbs off again cleaned again , so I'm a bit baffled as to what is going on . Big fat spark and good compression on all 4 . Has to be carb issue surely??
Regards

--- End quote ---

Yes, your timing is spot on as was mine but it was clearly not correct. I cannot explain why it was incorrect but we advanced it a tad and the bike suddenly sprang to life. It's just worth giving it a try as you seem to have pretty much exhausted other options.
Cheers

Navigation

[0] Message Index

[*] Previous page