carb floats

Posted: Thu Dec 17, 2009 5:05 pm

Hi, i just found this forum. I've had numerous hondas in the past, but just receantly aquired a 1981 750 custom that is in nice shape. I had the carbs rebuilt but the floats are bad. Does anyone know ehere I can get these? thanks in advance for any help. Jim

Posted: Sun Dec 27, 2009 3:46 pm

www.bikebandit.com has new floats for $60 each!! Why do you think the floats are bad?

Posted: Sun Dec 27, 2009 4:38 pm

They're $45 ea at Service Honda. $9 minimum shipping, but that is OK if you buy several things at once.

http://xtremeusa.com/fiche_section_detail.asp?section=125043&category=MOTORCYCLES&make=HONDA&year=1981&fveh=2981

Posted: Sun Dec 27, 2009 4:47 pm

Quote:

Why do you think the floats are bad?

because...he is reelkrzy! Laughing

the floats do go bad n these carbs, but usually not all of them. sometimes you can find whole racks of carbs for these bikes on ebay pretty cheap. might be helpful to have a parts donor anyway, for several reasons. did you get a reputable carb guy to do these? it can get pretty expensive and frustrating trying to get these carbs to work right if they are not done right the first time.

Posted: Sun Dec 27, 2009 4:54 pm

Welcome to the site Jim ... Smile

Posted: Sun Dec 27, 2009 7:01 pm

I's need someone to back me up on this one but I recall reading somewhere on another site that carb floats if left in constant contact with gas for a long time can became gasoline permeable and thus stop working properly. The DIY repair that I recall mentions recoating the float with shellac. With the floats removed and then dipped in shellac that's a pretty easy and cheap repair...if it works.

Anyone ever tried this?

If I can find the article I`ll post it.

Posted: Sun Dec 27, 2009 7:03 pm

Found it

http://www.ch250.net/techtips/15.htm

Posted: Sun Dec 27, 2009 10:15 pm

This may be relevant .

Copied from a BMW Carb repair procedure .

Note : they are talking about carbs on the BMW R75/5 model motorcycle, produced from 1969 thru 1973, with two Bing CV (Constant Velocity?) carburetors.

Quote:

Since then alcohols have been added to gasoline and the alcohols have attacked the shellac coating protecting the plastic floats. Gasoline can get into the floats and cause them to lose buoyancy.

Posted: Sun Dec 27, 2009 10:32 pm

If that was the case, I'd expect hundreds of people showing up with the same problem, and that isn't happening.

What's wrong with the floats? Did they get damaged or something? I really pretty rarely hear of bad floats in these carbs on two very active websites.

Posted: Sun Dec 27, 2009 10:55 pm

Gene ,

It should have been noted that the floats in question were on the BMW R75/5 model motorcycle, produced from 1969 thru 1973, with two Bing CV (Constant Velocity?) carburetors.

I fixed it .

Posted: Sun Dec 27, 2009 11:21 pm

reelkrzy hasn't really said what the deal is, other than he had the carbs rebuilt and that the floats are bad. All this guessing is just conjecture. Laughing

At any rate, welcome to our site Jim wave

Posted: Sun Dec 27, 2009 11:47 pm

genesound wrote:

reelkrzy hasn't really said what the deal is, other than he had the carbs rebuilt and that the floats are bad. All this guessing is just conjecture. Laughing

At any rate, welcome to our site Jim wave

Welcome!

Posted: Mon Dec 28, 2009 12:31 am

Well let's just say that long term carb float exposure to gasoline with additive alcohol is potentially problematic. Can anyone suggest an alternative float sealant lightweight enough for the job?

Posted: Mon Dec 28, 2009 2:18 am

i have been using Heet, which is isopropyl alcohol, for years without losing a float.... Bart moon

Posted: Mon Dec 28, 2009 8:50 am

old plastic floats break if you try to bend them

the 79k, has metal tangs[not OJ] on them, they are adjustable

there are many carbs which use these plastic floats

there is a list on site,somewheres ,gene posted it

Posted: Mon Dec 28, 2009 9:07 am

while he's gone, just chat quietly amongst yourselves.

Posted: Mon Dec 28, 2009 9:21 am

Posted: Mon Dec 28, 2009 9:24 am

thats it

gene as always comes to the rescue

Posted: Mon Dec 28, 2009 10:13 am

gottaride wrote:

Well let's just say that long term carb float exposure to gasoline with additive alcohol is potentially problematic. Can anyone suggest an alternative float sealant lightweight enough for the job?

Definitely wrong .

What my previous post stated was that alcohol attacks the shellac coating on the old BMW plastic floats . As far as I know , Honda never used shellac on any floats .

The point of that post was to point out that the suggested use of shellac for float repair probably would not be a good idea .

Posted: Mon Dec 28, 2009 10:44 am

A suggestion for float repair :

Clean and dip the float in fuel tank sealer .

Posted: Mon Dec 28, 2009 3:21 pm

what..like POR? that would change the buoyancy quite a bit, wouldn't it.

better to just get new floats, i would think.

Posted: Mon Dec 28, 2009 3:39 pm

I don't think it would change the buoyancy that much .

You'd be applying only a very thin coat .

I suppose the sealer could be applied only to the seams . That would cut down on the weight .