classic motorcycle forum

Motorcycle Discussions => Japanese Bikes => Topic started by: kairos on May 10, 2017, 11:54:02 AM

Title: frozen throttle slide
Post by: kairos on May 10, 2017, 11:54:02 AM
Hi ,
From my last post. I am cleaning the fuel system of my Honda H100. two stroke. The throttle slide has frozen in the carb Body.
I have tried WD40, slightly heating the body of the carb ( I have to be careful or I will melt the top plastic screw cap!) Tapping the slide with a wooden dolly using a hammer and tapping the body of the carb. also Levering the slide with a screw driver  (carefully).

I have run out of ideas. any help would be much appreciated. The bike has not been used since 1990.
Richard
Title: Re: frozen throttle slide
Post by: Rex on May 10, 2017, 03:55:38 PM
WD40 is no release agent, so either buy some decent stuff (I used to like Plusgas but don't know if it's still available) and soak it or use diesel, white vinegar or Coke if you don't want to spend anything on it.
Shame about the plastic as heat always works in the end.
Title: Re: frozen throttle slide
Post by: kairos on May 10, 2017, 04:24:14 PM
Thanks Rex,
No haven't seen plus gas for years. I did wonder about freezing the slide with a spray can it might work.

Richard
Title: Re: frozen throttle slide
Post by: iansoady on May 10, 2017, 04:34:59 PM
You can still get plusgas and it still smells the same. Although it might just be old stock I have.
Title: Re: frozen throttle slide
Post by: kairos on May 10, 2017, 10:51:15 PM
I have now done some research and yes Plusgas is still available.
Here are some other release agents.

Bilt Hamber Ferrosol ( Seems to be the best)
Plusgas Formula A

Holt Rustola DL110

Thanks for your help.
Richard
Title: Re: frozen throttle slide
Post by: Grunt on May 12, 2017, 12:47:06 AM
A good home made release fluid is 50% ATF and 50% acetone or paint thinners. Gentle heat i.e. Immersing in Boiling water, and then freezing the part and repeating this process can work as well and shouldn't harm any plastic parts. All you need to do is to get the two parts to expand and contract at different rates to brake the bond between them. Gentle and persistent is better than in a hurry with a hammer.
Title: Re: frozen throttle slide
Post by: rgsjohn on May 12, 2017, 08:05:19 AM
Quote
A good home made release fluid is 50% ATF and 50% acetone or paint thinners.
Trouble is..... acetone will attack plastic
Title: Re: frozen throttle slide
Post by: iansoady on May 12, 2017, 10:28:12 AM
It will indeed as I know to my cost....
Title: Re: frozen throttle slide
Post by: Rex on May 12, 2017, 12:01:21 PM
Anyhoo, I've just bought 500ml of Plusgas on Ebay for about a tenner.
The H100 stuck slide has done some good after all... ;)
Title: Re: frozen throttle slide
Post by: kairos on May 15, 2017, 03:32:19 PM
Hi Rex,
Thanks for filling in in my absence. You are nearly spot on . I had to order the Plus Gas and have just picked it up today . I will let you know how I get on.
Richard
Title: Re: frozen throttle slide
Post by: kairos on May 16, 2017, 11:51:04 AM
Success !!!  I sprayed Plusgas over the frozen throttle slide yesterday and this morning. The whole assembly is still attached to the throttle cable but the carb is unbolted from the engine.

I put the whole assembly in a bowl and poured boiling water over it. Whilst pulling the body of the carb against the throttle cable and gently levering the  throttle  slide. The whole assembly slid apart! It was only congealed oil that was holding the assembly together
there is no sign of corrosion.

Thanks for all your encouragement.

Richard
Title: Re: frozen throttle slide
Post by: Grunt on May 20, 2017, 07:58:28 PM
Quote
Trouble is..... acetone will attack plastic

Good point, I didn't think about that.

Any how it still makes a good release fluid and if you're lucky enough to have a Land Rover Defender the used ATF from gearbox oil changes is free as is thinners from cleaning your spray gun if you do any paint spraying. Dunno if turps would work as well but it could be worth a try and it shouldn't melt your plastic bits.
Title: Re: frozen throttle slide
Post by: Rex on May 21, 2017, 03:53:36 PM
Turps? Another part of history, surely? I don't know how good thinners would be as it evaporates too quickly.
Anyway, what's next on the H100 saga?
At this rate we'll have it running by about 2025!