Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: Harold 400/4 on August 26, 2025, 04:21:43 PM

Title: Choke flap screws
Post by: Harold 400/4 on August 26, 2025, 04:21:43 PM
Hi. Hoping for some help please.
My 550 K3 is leaking fuel from the carbs (the dreaded PD type 😎)
I have traced it to the metal fuel supply pipe between the carbs, and I think the O rings on each end have had it, and fuel is seeping out.

Nurse Julie has kindly supplied replacement O rings, thanks NJ.

My question relates to the screws on the choke flaps. Apologies if this has been covered before.  I need to remove the choke flaps to separate the carbs, and the screws are peened if that the the right term??

I have found a Honda bulletin which says that when you put them back, you should use hex screws and a locking type washer which you bend up to stop the screws working loose and disappearing into the engine.

Has anyone done this, or has a source for the screws and lock washers?
Is there an alternative method?

Many thanks
Harold

Title: Re: Choke flap screws
Post by: exvalvesetdabbler on August 26, 2025, 06:56:16 PM
On my 400F. I used stainless button socket caps.  Drilled the end of the screw with a center drill by a few mm. Put them in with locktite and then hit the end of the screw with a center punch to expand the end bit so even if they worked loose they weren't on a one way trip into the engine.  That was 20 years ago and they are still ok.

Regards
Dave
Title: Re: Choke flap screws
Post by: Oddjob on August 27, 2025, 12:46:03 PM
I’ve used stainless screws, slightly longer than standard, and spring washers with a dab of loctite.
Title: Re: Choke flap screws
Post by: Harold 400/4 on August 27, 2025, 02:37:30 PM
Thanks guys.
Great to hear from you Ken!
All the best for a speedy recovery. 👍