A question for VH owners

[david.anderson]

Keith
My bike is 9 to 1 compression, 56mk1 cam ported head and 32mm carb. 3.5 cut away, 105 needle jet needle in centre clip and 250 mains.
Another VH, reverse cone megaphone inside barrel muffler, 10 to 1 compression, 56mk1 cam with HS inlet follower, flowed and ported head lightened rockers, 32mm carb. 3.5 cutaway, 105 needle jet with needle lifted to lowest clip and 310 main jet.
No ethanol in the fuel and I normally run 98 octane pump fuel. With ethanol in the fuel the jetting would be slightly richer.
Your backfiring will however be due to the idle circuit unless your timing is out/retarded. I will bet that a 19 pilot bush will fix the problem. Although I do not have an amal premier, I tuned a friends bike that is fitted with a premier and it needed to go from the supplied 17 pilot to a 19.
David

[Keith.owen]

Hi David,
Thank you for geeting ack to me.

I shall acquire some bigger pilto jets and give them a try.

thanks,
keith

[Keith.owen]

Following David's suggetsion I fitted the next size piot jet up - No. 21. It seems to make a difference.
The throttle slide drops lower so I am not idling on the cutaway so much, but on the pilot (throttle stop screwed out further).

The bike ticks over at about 550 RPM (if my Chinese odometer/tacho is to be believed) and it just seems to be much happier - goes better and no back firing.

Dare I say it's fixed (perhaps better not to tempt the Gremlin)?

Keith

[TonyBaxter]

Is the slide worn in the carb? If it slops around in the bore that can affect tickover.

[Keith.owen]

Hi Tony,
It's brand new!

keith

[TonyBaxter]

Hi Tony,
It's brand new!

keith

Well that's covered that one then!