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Honda 50 Carb Cleaning........Help!!

Cupajo

New member
There seems to be lots of info about what chemicals to avoid for cleaning these carbs, but little about what to use.

Is there an economical source for an ultrasonic cleaner such as the manual recommends for cleaning the carbs?

Is the an Ethanol tolerant fuel line availible?

I have recently been well educated in fuel additives, so lets skip that please.

Thanks for any help,

Cupajo
 
I have always successfully used regular carb cleaner available at your local auto parts store. It is potent so don't let any get on rubber or plastic parts.
 
I do not use anything stronger than brake clean. I will not hurt the plastic parts. You should change the o rings etc anyway.

There is ethenol tolerant fuel line available...at least 5/16 in diameter. I am not sure about the smaller hoses that are actually on the motor at the carbs.

Mike
 
Thank you both for your quick replies!

Any info on the ultrasonic cleaner?

I have a manual and am a firm believer that no matter how excellent the book may be, there are always experienced folks to learn something new from.

CJ
 
The ultrasonic cleaner is the way to go if you can find one. They are pretty expensive. I have heard of some guys who have used an ultrasonic jewelry cleaner.

After I use the ultrasonic cleaner, I only use the brake clean to check the flow through passages and the spray out of idle ports.

If you are going to do a lot of carbs, it is worth the investment.

Mike
 
I've been under the weather a bit, but today pulled the carbs and there is no evidence of any contamination in any one of the three!

My next task is to give them a thorough inspection and cleaning to include replacing seals, gaskets etc., re-assembly and installation.

I'll pressure test the tubes and passageways within the carb, but a high powered light shows the tubes to be clear.

I've been involved with mechanical repair work for over 50 years and highly regard advice from those with more specialized experience than I.

The hoses are like new and may very well be as the motor has been maintained by a Honda dealer since it was new.

I'll next check the water catching filter, fuel tank hoses and the hose connections at the tank and on the motor for blockeage etc.

I replaced the fuel filter in the engine even though it looked brand new too.

All your information is appreciated and any ideas you may like to share will be gratefully recieved.

CJ
 
You must have some running issue, but you never said what is going on with the motor. It may not be the carbs that are causing the problem....it may be something else.

Let us know.


Mike

Bill H PTC USN Ret....I like your closing...A manual is a cheap investment. It could not be more true.
 
The first time in the water this year the engine wouldn't idle or come up to speed.

It would only run when the choke was engaged and then at about 1/2 power.

Reading various posts on line led me to believe there must be a problem with the carbs.

I replaced the engine fuel filter even though the old one looks new.

I have been treating the fuel with Startron, but not being careful to keep the tank full or not using fuel several weeks old.

I've been told by a friend that I should be using 89 Octane and that the water trap & drain filter cartridge should be replaced each season.

The motor saw very little use last year and the filter was almost new.

Should I replace it anyway?

The squeeze bulb and fuel line are a couple of years old.

Should they be routinely replaced too?

Lastly, what solution should I use in the ultrasonic cleaner?

Many thanks for sharing your vast knowledge,

CJ
 
Re: Honda 50 Carb Cleaning........An Up-date!!

Today I finally had time to do a detailed inspection and cleaning of the carbs.

The parts show very little wear and no gum or sludge or sandy residue, confirming the sellers comment that the engine wasn't used much. (The over-all condition of the motor points that way too!)

It hasn't had a lot of use since I got it either.

Using a magnifier to help my aging eyes revealed that each of the three tiny tubes had very tiny ports midway along its length that were blocked.

There was a build up of what looks like a carbon deposit (or some baked on substance)for a half inch or so on that part of the tube.

The hoses all are fine and when I blew the brake cleaner through each port there was no sign of any grit or other contamination.

I'm short one gasket set, but hope to get this thing back together in a few days.

Thanks again for your guidance,

CJ
 
Also check the tiny tubes (idle jets) for very small cracks near the base. Also remove the idle mixture screw and be sure that the passage is clear from where the top of the tube goes into the top of the carb. Then lightly install the idle mixture screw and check the small pin hole size ports at the top inside rear of the carburator. You should get a nice spray out of all of the holes if you spray up through where the tiny tube seats in the top of the carb.

These passages generally control the idle. Double check the main jet to be sure there is not a clog.

The idle mixture screw should be turned out 1 turn from being fully seated.

It is also possible that your timing may be off by one tooth or so of the timing belt. Generally, pulling the choke out does not improve runability, but stranger things do happen.

Mike
 
Re: Honda 50 Carb Cleaning.......Idle mixture screw?

I have the shop manual open on my desk and there is no such designation on the parts breakdown.

Could you be referring to the pilot screw?

According to some things I've read they can be a beast to deal with and i haven't disturbed them.

The pilot screw breaks off and has to be removed with an easy out??

This is a BF 50-1 from 2001.

Thanks for your replies,

CJ
 
Re: Honda 50 Carb Cleaning......Correction---BF50A1

Looking over the carb details in other parts of the manual hasn't shown me the idle mixture screw either.

CJ
 
The idle mixture screw (American mechanic) and pilot screw (English mechanic) are one in the same. If yours has the little chrome plated "limiter" cap on it, the manual will tell you to break it off to remove the screw. A nice person on this forum (who shall remain nameless) gave me a technique for getting them out without breaking them off. Here it is;

The limiter is held on to the end of the screw with a dab of Loctite thread locker. If you heat the limiter cap with a soldering iron and simultaneously (and gently) pry it away from the carb, it will soften the Loctite and the cap will pop off. Under the cap will remain a nice little slot head for a mini screwdriver that you can use to adjust your idle or remove the screw.

If that doesn't work and the thing breaks off anyway, not to worry. I use a very sharp dental pick to stab into the flat, smooth head of what is left of the screw and turn them out.

Yes, it is a pain but it's what you have to do to get them out. The spring that is holding pressure on the barrel of the screw makes it difficult but if you use a sharp pick and contact the outer edge of the flathead, you can get it moving. When you think the screw threads are disengaged, it will still be hard to get out of the hole because of the O-ring seal being caught in there so using two picks to pry it upward and out will probably be necessary. A little shot of WD-40 can help get things moving. JUST MAKE DOUBLY SURE THE THREADS ARE BACKED ALL THE WAY OFF BEFORE PRYING! Several additional left turns after you THINK the threads are disengaged will ensure this.

You can then use a Dremel cutting wheel or your Xacto jewler's saw to put a slot in the flathead for a screwdriver. Or, you can go all original and put in a new screw set complete with new limiter cap.

Be advised that those "tiny tubes" can be a booger to get completely clean. And, the O-ring at the end is CRITICAL to the operation of the carb. I usually just replace them. Honda calls them a "jet set" and sells them with a new O-ring. Worth the money and will eliminate any doubt and confusion if you have additional carb issues. At the very least, do not reuse the old O-ring!

While you have them apart, pay particular attention to all the passages in the fuel bowl. I don't know if you have accelerator pumps on yours but if you do, they are also CRITICAL in the operation of the carb. Whatever the case, make real sure that any internal passages in the bottom of the fuel bowl are completely free and clear. Use the spray can straw to flush them out.

Once you have the idle screw out, prop the throttle plate wide open by wedging a mini screwdriver between the linkage arm and body. You will now be able to see all four fuel orifices in the throttle body. Use WD-40, brake clean or carb cleaner or all three to flush and back-flush those orifices. I usually start with WD and finish with carb spray. The straw is your friend! Use it to push up into that hole where the jet set (tiny tube) seats and spray your blues away! Cleaning that passage should have you seeing a pretty strong stream coming from the three orifices-two high speed-one intermediate-clustered in a triangle in the throttle body. You should get some from the idle orifice as well.

Flush the idle circuit by holding your finger over the idle orifice in the throttle body and injecting the straw into the hole that the mixture screw came out of. Then, hold your finger over the idle mixture screw hole and spray into the orifice. Takes a steady hand and dead aim. If you do this a couple of times you will get the hang of it. Having a couple of carburetors to practice on and compare will make you an expert Honda carb cleanin' man!

Ultra sound?? We don' need no stinkin' ultrasound!
Good luck.
 
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Re: Honda 50 Carb Cleaning........WOW!! What a wealth of information!!

Hi jgmo,

Thanks to you and hondadude I have enough info to "git er done"!

Many thanks and I'll certainly call on you guys if and when I have more problems.

CJ:)
 
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