View Full Version : Ironhead Putting the Mikuni Carburetor Back Together

23rd November 2011, 22:15
Hi all,
I took the Mikuni apart for a cleaning and videoed that.
But in the edit business I somehow failed and lost part of the clip.
So I guess there is no disassembly video to watch. :frownthre

I did put the carb back together after an overnight dip in carb cleaner, and was able to film that.
It took me two videos to post it on You Tube.
A couple of disclosures are in order here........
(1) You will notice I call things such as the float needle a float.
I meant to say needle, but it did not come out correctly.
My speech talents are thin.
Also, you will find any number of times I do this (misname things) and I guess that is because I am concentrating on what I am doing rather than what I am saying.
It sure does not come off very good, but I YAM what I YAM.. :o

(2) Also, I just discovered myself today that I installed the float lever upside down. Groan-n-n.
Watch the video and you will see me install it correctly, then change my mind and flip it over.
This is wrong.
The offset fingers on the float lever should be facing up towards the top of the carb.
It was already posted on You Tube and I could not correct the error..... I recommend you watch these full screen to be able to pick up better detail.

Part 1:
Reassembly of the Mikuni VM38 Carb-Part 1 - YouTube

Part 2:
Reassembly of the Mikuni VM38 Carb-Part 2 - YouTube

Next I will be installing the Mikuni on the bike and getting it to start (or not).
I hope to be able to cover using an internal throttle cable with the Mikuni.
It will be a first for me if it works, but we shall see.

24th November 2011, 05:32
VCM38? and Ya expect Her to start? witha friggin Honda mower in shop?
Heres my opin..after reading Yours for years..
Tweak twice..kick once..bitch slap anyone reading..then do a vid on S n S E...You pissed yet?

24th November 2011, 05:45
Thanks for the videos. After watching them I realized I did not do anywhere close to an adequate job cleaning my carb.

24th November 2011, 05:45
What happened is in 1971,a member bought a XLCH.
Liked the right hand shift..speed,girls and livin by the sea.
Now..still wont sell it..or the girls... was into flat trackin..
Wy dont You give me a price on this CH..

24th November 2011, 05:54
Oh..if Ya pissed off PG...or challenged Him on carbs..Good luck..byob...

24th November 2011, 13:54
Good stuff PG. I'm exited for you. Getting your Mikuni back on the bike after all this time

24th November 2011, 15:54
Good stuff PG. I'm exited for you. Getting your Mikuni back on the bike after all this time
OK, just to be clear about the Mikuni here...........
I have cleaned the Mikuni just to make certain it is able to start the engine as it always has.
The only reason I am putting the Mikuni back on the bike is have it ready to test the carb belonging to member Bhakakha.
I also want to try to see if I can use the setup provided to me by member Blznfst.
He sent me a set of handlebars that his father in law rigged up to use an enclosed cable with a Mikuni. So we will see how that goes.

After this work is finished I will remove the Mikuni setup and install the Bendix back on the bike.
This is the plan right now.

I still am of the opinion that a Mikuni is the smoothest running carb (with easy starting) that one could install on a Sportster.
Nothing is going to change that.

The Mikuni negatives for me are:
Having the cable hanging out in the wind is not something I like.
Having the engine run and idle so smoothly is something I do not like as well.
The Mikuni sticks out further than other carbs, something I do not like.

So with all those negatives, I still say the Mikuni is the best.
But, I will be installing the Bendix back on the bike after this work is finished.
With the Bendix, I have the enclosed cable and the engine starts and runs well.
As shown in the 2nd video of starting with the Bendix, how can a bike run better than this?
So that is what I intend to do and hopefully can help someone along the way who may have run into some of the problems I have encountered.

2nd December 2011, 14:46
Is ther any way you can take and post some pictures of that Mikuni hooked up to the through the handle bars throttle cable. I'd like to see how that connection will be made to the carb.

2nd December 2011, 15:02
Is ther any way you can take and post some pictures of that Mikuni hooked up to the through the handle bars throttle cable. I'd like to see how that connection will be made to the carb.

I plan to do just that in the (hopefully near) future.
I too am curious.
at the present time I find myself very busy with other things, the Christmas Holidays coming up etc., but I will get to it.

2nd December 2011, 22:51
I worked on my Mikuni to get the air cleaner to sit a little closer to the bike. I made an aluminum adapter that goes between the air cleaner and carb. Then I cut off about 3/4 inches of the inlet tract on the carb and smoothed in the carb entrance.



You can see the adapter on the back of the air filter plate. This is the stock HD air filter from about 1972 (with larger air filter element).

2nd December 2011, 23:08
That is a nice job you did with the air filter backing plate!
Neat installation.,
I never thought of sawing off a bit of the carb to move the filter in. Looks like it works well.
Question: What is the red material around the carb barrel and the two screw holes? It looks like red Loctite.