Honda-SOHC

SOHC.co.uk Forums => CB650 => Topic started by: jameser on January 03, 2008, 08:05:34 PM

Title: CB 650 carburation
Post by: jameser on January 03, 2008, 08:05:34 PM

Hi can anyone help me

I have just rebuilt a CB650 and got it running but everytime I turn on the fuel the carbs flood
petrol pours out of overflows The float heights have been checked and set at 12.5mm as per haynes manual I have tried setting them at 11mm but same thing happened
they are Keihin PD51A carbs
Starting to pull my hair out but there aint much left

                      Thanks
                                 James

Title: Re: CB 650 carburation
Post by: Dave M on January 04, 2008, 07:28:13 PM

If it's pouring out of the overflows then one or more of the float valves isn't sealing for some reason.

Are the float needles and seats in good order?

Are they clean and free to move with the floats?

Are the floats OK? Not punctured and full of fuel?

Title: Re: CB 650 carburation
Post by: SteveD CB500K0 on January 04, 2008, 09:20:15 PM

Quote from: Dave M on January 04, 2008, 07:28:13 PM

Are the floats OK? Not punctured and full of fuel?

This happened to me on a Bandit. The float looked OK but was full of fuel - the bike ran on three and pissed fuel from the overflows. A bit of araldite and it was fine.

The spellchecker wanted to put "heraldic" in there!

Title: Re: CB 650 carburation
Post by: clive on January 07, 2008, 03:03:10 PM

hi,  i've got the same problem on my cb500/4
    could you answer the following questions,
    1)  how do you check the floats, or is it obvious.
    2)  what did you do with the araldite.



thanks,

Title: Re: CB 650 carburation
Post by: SteveD CB500K0 on January 07, 2008, 06:46:04 PM

A. I don't know about 650 carbs specifically, but to check floats you have to do two things:
 1. Make sure they float (seriously - see item B)
 2. Measure float hight and adjust per the manual

B. My Bandit float had a hole in it and had filled with fuel. I drained the fuel, dried the float and araldited the hole. Saved me the

Title: Re: CB 650 carburation
Post by: Dave M on January 07, 2008, 08:49:50 PM

If you shake the float you may hear the fuel sloshing about inside.

Alternatively weigh them individually and see if any are considerably heavier.