Carb Rebuild

[Blackduck KS]

Hello all,

I have some questions on rebuilding carbs on my 97 standard.

I have a fuel leak on one of the T`s between #4 & #6 well its more like a waterfall than a leak, and it has always idled rough and only at about 200 to 300 rpm, best guess according to tachometer, was never close to the 1000 mark since I`ve owned it.

With that said, here is what I know about the bike, to my recalculation of what I remember, that I was told by original owner about the bike. not even sure on it totally, I`m getting older, memory not what it use to be.

Like i stated before it`s a 97 standard, it has an interstate tank and carb setup on it, the air box has no foam and has a K&N reusable filter, and it has been desmogged, and the exhaust has been drilled out.

My questions are.

1. Is there any difference in carbs from one model to the next? ( Standard, Tour, Interstate )

2. According to the carbs on my bike what is the difference in the carbs,
    This what I found on mine, Brand ( VP KEIHIN JAPAN ) #1& #2 are  (KOA A K B06 ) Model
    #3,#4,#5,&#6 ( KOA A B13 ) Model, I couldn`t find any info on them at all. The second ( A )
    in the sequence has a rectangle around it, this is stamped on castings.

3. Do I need to re-jet the carbs, looking at them, it was never done, from all the work that was done to   it, the jets are #35 slow , and #100 mains, it has always run well at top end, only prob has been idle.

4. What kind of lube should I use to reassemble if any, I read all kinds of stuff to use, what do some of  you guys & gals use.

Well that`s all I can think of for know, sure I`ll have other questions once I start the rebuild process,
 although I don`t imagine it`s will be any difference than doing an auto one.

Thanks for any help in advance and it`s greatly appreciated.

[98valk]

try tightening the end nuts of the two thru bolts of each carb bank. these bolts hold them together and which keeps the T fittings tight. I've had to do it twice in 80k miles when they started leaking. Those ends nuts will get loose over time. simple fix and a rebuild is not required.

all carbs are same all yrs/models 49 state. California carbs have extra vacuum ports for charcoal canister.

stay with the OEM stock jetting. 

see example #2  https://fboignition.com/articles/sparkplugreading
adjust idle mixture screw so the end of threaded area of plug is not carboned up.

[RonW]

if you like, watch D-ray Smith and Tom Assay (carb assembly) videos.

[The emperor has no clothes]

The Interstate models have different spring in the constant velocity setup. I would just stay with what you have stock jets and all. Check your float needles and replace the o-rings in the fuel rails. You are aware of the idle adjustment screw ?

[Jims99]

If it’s still apart, I would definitely change the o-rings on the fuel rails and air passage rails. Tightening the nuts on the end usually will work, but if you haven’t installed them yet, just put in new ones. (6x1.5mm and 7.8x1.9) There’s also an upgraded float valve you can put in, I’ve used them on all my valks. (KL 18-8955)

[ckahler]

Sometimes tachometers are not accurate or sticky at low RPMs. I would verify that 200 - 300 rpm reading is correct.

[98valk]

If it’s still apart, I would definitely change the o-rings on the fuel rails and air passage rails. Tightening the nuts on the end usually will work, but if you haven’t installed them yet, just put in new ones. (6x1.5mm and 7.8x1.9) There’s also an upgraded float valve you can put in, I’ve used them on all my valks. (KL 18-8955)

"There’s also an upgraded float valve you can put in"

Why is (KL 18-8955) an upgrade?

Randakk says stay with OEM and “I don’t arbitrarily replace parts, only what is needed. The factory float valves often last longer than the motorcycle. They’re also expensive. But, I will not use aftermarket float valves, and here is why. That’s chrome plating that is coming off this aftermarket float valve. The factory ones never do that.”
https://www.randakksblog.com/more-problems-with-aftermarket-float-valves/

[Blackduck KS]

Thanks all for the great advise.

I think it`s time to do something with it, I made 2 rides on it going to store and back, started with full tank, lost 3/4 of it out on the ground, was so scared to ride it home on the second ride, when I got home, I put it in the garage and started tearing it apart.

I already have them all torn apart to rebuild, I have cleaned then with Berryman B12 and the only thing I found was the black dirt left in the pan from cleaning them, everything was pretty clean, the floats are the only thing I found inside the carbs itself was bad looking, they where discolored and
some yellowish orange residue on some of the other parts, I believe was left over fuel that dried on them before I cleaned them. Oh and one of the ends of the #10 VALVE SET,STARTER was bent and I tried to fix it and it broke off. so I have to replace it.

I bought a Randakk`s kit AB26-1629, in fact I just got it in the mail.

So I think I`ll get started on it and put it back together, and only replace the parts that I feel need it
and some of the suggestions made and hope for the best that`s about all I can do at this point.

I`ll re-post when I get it back together, it will be awhile because I don`t plan on getting in any hurry
and I`m going to a wood carving show in a couple weeks and I still need to order some parts for it.

I want to thank everyone who posted your help on this, I really greatly appreciate any and all help thanks again.

To be continued.

[Ron in Buffalo]

if you like, watch D-ray Smith and Tom Assay (carb assembly) videos.

I used Tom Assay videos to rebuild my carbs. I used the Redeye kit.

[SCain]

I bought a Randakk`s kit AB26-1629, in fact I just got it in the mail.


This is the All Balls Kit, I have never used one but I have heard good things about it .

[rug_burn]

     Another thing:  look at the diaphragms with their needles.   On my bike, a '97 tourer, Calif. model, I've had a couple little cracks in the rubber diaphragms.    The diaphragms unfortunately are expensive:  about $115 each.    I replaced one when I rebuilt the carbs and then discovered another much later, which I glued back shut with Pliobond.   It ran good before I discovered this leak, and ran good afterward.   MAybe small cracks don't make that much difference but they are only going to get worse;  new diaphragms would be best.    I doubt if that glue held up for much more than the first minute of running time, but I haven't checked yet.
     My bike sat for only about a year with CA gas, but that was enough to deposit a layer of varnish on the needles.   I had to scratch this off a few of the needles using my thumbnail.  It didn't get deposited on all of them, I think maybe just the left side carbs.   There're also those o-rings at the base of those needles, which will need replacing after 26 years, don't forget.
     Good luck-  keep us informed on how it goes.

[Blackduck KS]

Hello All,

Just an update on carb rebuild, I now have it all done except one part, I had to order it from
Honda Direct Line, and it`s on it`s way.

Here`s what I found when rebuilding and cleaning everything, to put it all back together.

Everything was real clean inside all the carbs, had very little varnish any where, just a little discoloration on some parts, but was removed with a little  carb cleaner ( Berryman B-12 ) but I have always used Lucas octane and stabilizer since I have owned it.

Other than the part I broke trying to fix it, the bent tip on ( #10 VALVE SET,STARTER ) which is what
is on they way from Honda, I also found that the #2 intake O-ring about a fourth of it was gone.
 
When I was removing the ( #6 SCREW SET ) everything I read or seen on it, said to screw them
in until they seat, and remember how many turns, so I did the first one and it was 3/4 of a turn from bottom, so I thought to my self that`s not right, so I went to the next one, same thing 3/4 of a turn from bottom, so I went ahead and did the rest of them, same thing 3/4 of a turn from bottom, so
now I`m wondering, how it was running so good to begin with, I`m now at a loss as of where to set them at, so I went back to the spec and it has it at 1 1/2 turns to 2 1/2 turns, I though I would start them at 2 turns and go from there. What do you all think?

I`m cleaning or replacing everything I can while it`s torn down, I`ve replaced all the vacuum and fuel lines.

I got a question on the radiator though, I removed the cap on it and it appears to be about half full,
so I removed the left side cover, and the fill container is on the full line, is this level in the tank correct,
I have never messed with this before, I took it to my local Honda dealer to have all of it drained and cleaned and refilled, on brake fluid, coolant, rear end, so it would not surprise me if they even did it. I wont go in to what I think about Honda`s mechanics, this thread is long enough already,
I will say they are no longer in business.

So for now that`s about all till I get my parts, I`m pretty much ready to put it back together.

Thanks again for all the help from everyone's that has contributed there expertise and knowledge.  

[turtle254]

What are your jet sizes? Pilot jet might be changed to #38 instead of #35! 

[98valk]

What are your jet sizes? Pilot jet might be changed to #38 instead of #35! 

No!, don't use a 38 unless one wants less mpg. 38 PJ is much too rich for a stock bike with different pipes or not. the idle mixture screws can be opened up 4 turns, if the engine wants more than that then next larger size PJ is warranted.

http://www.factorypro.com/tech/tech_tuning_procedures/tuning_pilot%20jet,%20affect%20of%20size%20on%20idle%20and%20cruise.html

[turtle254]

What are your jet sizes? Pilot jet might be changed to #38 instead of #35! 

No!, don't use a 38 unless one wants less mpg. 38 PJ is much too rich for a stock bike with different pipes or not. the idle mixture screws can be opened up 4 turns, if the engine wants more than that then next larger size PJ is warranted.

http://www.factorypro.com/tech/tech_tuning_procedures/tuning_pilot%20jet,%20affect%20of%20size%20on%20idle%20and%20cruise.html

What I was saying was that 38 might be in their now, because of the settings he found. I wasn't saying to change them.

[Blackduck KS]

It had 35 PJ and 100 PJ, That`s what I took out and
that`s what the kit had in it, so I put the new ones in.

My bike has an interstate carb setup on it and tank, so could this setting
be due to that?

[Skinhead]

     Another thing:  look at the diaphragms with their needles.   On my bike, a '97 tourer, Calif. model, I've had a couple little cracks in the rubber diaphragms.    The diaphragms unfortunately are expensive:  about $115 each.    I replaced one when I rebuilt the carbs and then discovered another much later, which I glued back shut with Pliobond.   It ran good before I discovered this leak, and ran good afterward.   MAybe small cracks don't make that much difference but they are only going to get worse;  new diaphragms would be best.    I doubt if that glue held up for much more than the first minute of running time, but I haven't checked yet.
     My bike sat for only about a year with CA gas, but that was enough to deposit a layer of varnish on the needles.   I had to scratch this off a few of the needles using my thumbnail.  It didn't get deposited on all of them, I think maybe just the left side carbs.   There're also those o-rings at the base of those needles, which will need replacing after 26 years, don't forget.
     Good luck-  keep us informed on how it goes.

Has anyone tried Flexseal to seal The vacuum diaphragms?  As long as it is resistant to gasoline, it may be a good alterative to spending hundreds of $ on diaphragms.  Personally never used it, just axin'.

 

It had 35 PJ and 100 PJ, That`s what I took out and
that`s what the kit had in it, so I put the new ones in.

My bike has an interstate carb setup on it and tank, so could this setting
be due to that?

It shouldn't be, as stated above the only difference is in the diaphragm springs.

[Bagger John - #3785]

I bought a Randakk`s kit AB26-1629, in fact I just got it in the mail.


This is the All Balls Kit, I have never used one but I have heard good things about it .

Has any member posted a review on the site? I need to R&R a set of carbs on my Tourer and have a couple spare carb assemblies sitting around that can be bench-rebuilt and swapped.

If the All Balls kit is comparable to OEM quality I'll pick one up and proceed, else it's off to the fiche.

[98valk]

rubber cement works well for slide diaphragm damage. thin as possible coat.

https://www.familyhardware.com/product/Elmers-4-Oz-Rubber-Cement-Adhesive/971602?utm_campaign=441171417&utm_source=bing&utm_medium=cpc&utm_content=&utm_term=&adgroupid=1162185614479527&msclkid=c207f4c68646109f53dd91fcfea05633

[Blackduck KS]

Hello all,

Just wanted to update everyone on my 97 carburetor rebuild, sorry this is so late, the last four months
have been a nightmare, sense I started this in October, I`m now done with fixing all the leaks and
replacing all parts that I felt should be changed, I was a little scared to start it up, with all the  post about hydro-lock after rebuilds, but I hooked it all up, charged the battery, and hit the starter and
it cranked about four times and away she went, you wouldn`t believe the difference this made,
even me, because I thought it run great before I did the rebuild, so I let her warm up for about 30 mins.
and I attached my Carb Sync Tool, after about 45 mins. I was done and she was purring like the beast
she was designed to be, I really haven`t been able to ride much sense the rebuild, because of the weather now, but right after I got done, I drove it to the gas station and filled her up and went for an
11 mile ride, I have started her up a couple times in the garage and let it warm up, then shut it off, and
every time she fires right up faster than she ever did before, so needless to say I`m very satisfied with the results so far.

Also in case anyone is interested, I purchased a new tool for syncing the carbs, called ( The Digi Sync )
It`s a bit pricey at ( $ 215.95 ) for the one to do six cylinders, but well worth the price at how much faster it`s to use I think, it`s magnetic and sticks to your tank and has all six vacuum read outs at once and the RPM. You can check it out here if your interested  ( https://thedigisync.com/ ) Oh and for all cheap people out there they now have a rental program for ( $75.95 )  

Well that`s my 2 cents worth, just wanted to update, everyone on how my rebuild went, keep the
shinny side up, and the gremlins at bay, stay safe and well, till we may meet again. Blackduck KS.