Mikuni BS32 issues

[Guest]

Ok I went to the salvage shop yesterday and picked up another carb since a welding mishap rendered #2 useless. It turns out I didn't notice a difference on any of it until I cleaned it. The pilot jet is a different design. No idea what bike it came off of just knew the ID matched mine. My question is will my original pilot jet swap over or will I need to get the other style in the same size as the other one or just go back and find another carb?

[tom203]

"Welding mishap" ??
is this salvage carb a Mikuni?' You want all 4 carbs to be real similar or fun awaits. Post in parts wanted forum

[nate25tenn]

Welding mishap = broken float tower and still not great at welding aluminum. The salvage shop carb replacement is identical to the original minus the pilot jet circuit. Jetsrus lists that mikuni uses two types.

[Crankthat]

Could you post a pic or two side by side?
I have seen the needle jets different before.
Same bike, same style carb, just different needle jet.
Have you checked them?
I would hazard a guess you can replace with the original from broken body if everything else on the new is same as old.
I would compare the two bodies and parts attached to make sure everything else is the same though.
Would not want to chance having to remove or reattach carbs on that bike for a avoidable mistake unless running pods.
It may be a aftermarket jet or even from a 650 0r 750 as they also used the 32.
For that matter The original carbs on your bike may have been fitted with aftermarket as you have the 4-1 exhaust.

[nate25tenn]

Will send pics as soon as I get home.

[chuck hahn]

Of both the bodies and the jets please.

[Nessism]

The carbs are zinc, not aluminum.

Some pilot jets have holes through the side and others don't. Can't remember if they are interchangeable, but there are various threads in the archives detailing this difference if no body comes up with the answer in this thread.

[nate25tenn]

The difference in the pilot jets is that both have holes in the sides but only one has a hole through the center unless its still clogged but I don't believe that's the case. The difference in the bodies is that on the origional you can see through the pilot jet hole and how it comes out inside the carb throat. On the new one that hole leading up the throat isn't there. That's as best I can describe it until this afternoon when I get pictures. Thanks for the insight so far everyone.

[nate25tenn]

[Steve]

Assuming you are numbering the carbs correctly (#1 is under your clutch hand, #4 is under your throttle hand), I have a #2 carb with the hole in the throat.

However, I'm not sure if it is for the smaller fours (550/650) or the larger fours (750/850).

I will PM you with a request for some specific measurements.

EDIT: Just checked the carb and found that it is for the larger fours and will not work for your bike.

.

[nate25tenn]

EDIT: Just checked the carb and found that it is for the larger fours and will not work for your bike..

What makes it incompatible if the jets match and it mounts to the rack? I just want to make sure there's no way to make this work before i go back searching for another one. Thanks for the help.

Internet searching at work has revealed its a Mikuni BS32SS. Still no idea on interchangeability of the jets but at least its a step closer.

[Steve]

Not sure exactly what the difference is, but I have noted a few carbs with "the hole" over the years. Most of them were not directly associated with a bike, so I can't say for sure what bike they came off of. I would like to compile a list some time of all the little detailed differences in the carbs (other than just jetting).

.

[Crankthat]

Just went out to the garage and grabbed a set of 550L 81 carbs that were taken off a running bike.
A bit of history on the bike.
I had bought it a number of years back and it had been sitting for a dozen or so years.
Before that it had been ran by the owner and son since new.
No carb work had ever been done to it when I had purchased.

My best friend wanted it.
I gave it to him.
The bike was not running.
He took it to a private shop to fix.
The shop replaced the petcock that I knew was bad and replaced one of the carb bodies.
By the time the work was done I had cleaned the carbs on my 750L 81 that I had purchased and had now knowledge on what was involved in repairing/cleaning this type of carb.

When he had the bike running I asked him what was repaired.
He had said petcock, carbs rebuilt, and a new body bought and installed on #1 carb.

I asked why they felt the need to replace the one body.
They had told him the one was pitted from corrosion and could not be used.
I was doubtful that was the real reason but whatever, what is done is done and they no longer had the original or so he was told.
After crossing the double line on a short curve he decided he no longer wanted the bike.
Good call.
I bought it back from him for what he had in it.


Looking at the carbs I see the one that was replaced is minus the hole and all the others have the hole.
The bike seemed to run fine with that arraignment.
The carbs were never vacuumed synced only bench synced.
It should run fine.

[Crankthat]

My spare set of 750L 81 carbs do not have the hole.
Never paid attention the set that is currently on the 750 so I do not know if they are the same or not.

These are the ones from the 550L 81.
#1 body
[IMG][/IMG]

# 2
[IMG][/IMG]

#3
[IMG][/IMG]

#4
[IMG][/IMG]

The one diff4rence I had noticed when I took the carbs apart after getting the bike back.
[IMG][/IMG]

The circular indentation where the small flat rubber washer goes on the bottom of picture the replaced body the indentation is raised compared to the originals.
From information gleaned from this site I have learned that it is in fact a plug.
The hole where the plug was inserted was part of the manufacturing process and needed to be stoppered.
The rubber gasket or washer was put over to ensure it will not leak.

I find the difference in the carbs to be interesting and would like to know more myself.

[nate25tenn]

It's going to work fine. I've already started putting it back together. The pilot jets do interchange, the old one I pulled from the salvage body was so crusted I couldn't get it clean. Doesn't matter as it was the wrong size anyway. Everything swapped over from the other body. Here's some information I found in regards to the BS32SS.