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Accelerator pump leak

Posted: Sun Apr 07, 2013 9:29 am
by Ratrap
Hi Everyone

A quick question.
On my 82 when I twist the throttle thus activating the accelerator pump I have fuel dripping from between carbs 3 and 4.
What should I be ordering while I remove the carbs?

Thanks

Gavin
Cape Town
South Africa

Re: Accelerator pump leak

Posted: Sun Apr 07, 2013 2:02 pm
by Ratrap
OK I got the carbs off. The leak is at the float bowl carb interface.
When I removed the bowl there is no O ring where the accelerator pump injects into the base of carb 3!
I assume there should be an O Ring here??

Re: Accelerator pump leak

Posted: Sun Apr 07, 2013 2:53 pm
by EMS
Gavin: Welcome to the ICOA forum!

Yes, there is. It is shown in the parts diagram as part of a seal kit. (Honda calls it "packing set"). Most carb seal kits that are being offered have it. You may be able to get a single part from Randall Washington , "Randakk".

Re: Accelerator pump leak

Posted: Sun Apr 07, 2013 4:08 pm
by Jeff Bennetts
While your carbs are off just buy a new accel pump kit, if your's is original the diaphragm is probably pretty tired, the special square shouldered O-ring will come with the kit. Also make sure all your accel pump passages and the brass nozzles that stick up in the carb throats are clear, when you bench test the carbs each nozzle should have a strong stream.

Welcome to the forum.

Re: Accelerator pump leak

Posted: Sun Apr 07, 2013 9:25 pm
by steve murdoch icoa #5322
Welcome to the site, Gavin.
The best money i have ever spent on my bike is the Mike Nixon Carb Book.
http://www.motorcycleproject.com/motorc ... orkv4.html

Re: Accelerator pump leak

Posted: Mon Apr 08, 2013 5:07 pm
by Mike Nixon
Heard my name mentioned. I can supply the o-ring separately. Give me a shout.

Re: Accelerator pump leak

Posted: Mon Apr 08, 2013 9:04 pm
by daves79x
Jeff:
The squared-off o-ring goes with the air-cut diaphragm. The accel pump takes a plain (but odd-sized) o-ring. I know you know that, just so Gavin does not get confused. Thanks Mike for stepping up!

Dave

Re: Accelerator pump leak

Posted: Tue Apr 09, 2013 5:34 am
by Jeff Bennetts
daves79x wrote:Jeff:
The squared-off o-ring goes with the air-cut diaphragm. The accel pump takes a plain (but odd-sized) o-ring. I know you know that, just so Gavin does not get confused. Thanks Mike for stepping up!

Dave
Thanks for correcting me Dave, don't want to get Gavin headed down the wrong road :oops:, the carbs can be confusing enough as it is. I have seen carbs that PO's have used an off the shelf O-ring, bad idea, an Ill fitting or cheap O-ring can swell and block the accel pump orifice and restrict the flow.

Get one from Mike.

Re: Accelerator pump leak

Posted: Tue Apr 09, 2013 2:53 pm
by Ratrap
Many thanks for all the advice. I drilled and tapped the pressed in jets and extracted them without any problems.
I am ordering a master carb rebuild kit some Air Tees and Mikes book from Randakk.

Re: Accelerator pump leak

Posted: Wed Apr 10, 2013 8:21 am
by Jeff Bennetts
Ratrap wrote:Many thanks for all the advice. I drilled and tapped the pressed in jets and extracted them without any problems.
I am ordering a master carb rebuild kit some Air Tees and Mikes book from Randakk.
:text-goodpost:

Re: Accelerator pump leak

Posted: Wed May 08, 2013 4:47 pm
by Mike Nixon
Incidentally, the accelerator pump cover to bowl interface is a frequent leak area, with the 80 and later being worse than the first year models. I and other rebuilders take proactive steps to preempt leaks here. The o-ring needs to be there, for sure, and in good condition. But the joint will often leak despite the presense of the o-ring due to warpage of the pump cover. In this pix I am checking for this very thing with a mirror.

Image