Mikuni on Briggs

#1
Allright I have a 5HP briggs flat I want to remove the tank and tank mount carb and install a Mikuni.I searched the past posts and have found that the 22MM is the best size recomended.Question is will it bolt to the Briggs with
the flanges on it or do you have to get an adapter?Also if
adapter is required do they make it for the flange mount or the boot mount or both.Thanks for any help.:confused:
 

Kenny1

New Member
#2
I just went and looked at a couple of my bikes. The Mikuni's mounting holes are spaced avout 2" apart and are horizonal across from each other. The 5 hp briggs I have has about 1.5" bolt spacing and are about 45 degrees. If the engine you have is like mine it wont just bolt up. The carb would be leaning way off to the side and the bolts don't line up. If you can find an adapter to fit the two together that would be the way to go. My Mikuni is on a clone motor and I would never go back to a stock type carb. It runs so much better and is easy to adjust. And it looks cool too.:thumbsup:
 
#3
Thanks dude,I think they look cool too and heard they are easy to adjust also.I think I can build an adapter if needed was just curious if there were any made for a good price.What size Mikuni are you running?:scooter:
 

Kenny1

New Member
#4
I'm running a 22mm on a 6.5 clone. Its more than enough carb for the engine its on and even at high rpms it keeps up (no governor on it). They are super easy to adjust and the throttle cable hook up is breeze. I'm thinking you could use maybe a 18 or 20mm and be good to go. I have not used one of the smaller ones, maybe there is one with the right bolt pattern for your briggs.
 
#5
I plan to start looking for a Keihin carb & manifold from a Honda XR-75/80 or an XL-100/125. The Keihin is a much better carb than the Mikuni.

The engine side of the intake manifold mounting holes are in the 1 7/8" coc range. You will most likely need to rotate the mount at the engine. I don't know what the best way to do that is yet. The older XR carbs were spigot mount & could be rotated in the manifold.
 
#6
Keihin is a better carb that the mikuni. Yeah ok, Any evidence to prove that statement....Or is it really just personal opinion???jonnybiker
 
#7
Do you guys know about the mounting of one on the Briggs.JM said something about a spigot mount I guess thats the kind with the rubber manifold tube and clamps?Seems like an adapter would be easy to fab up for one like that.What size Keihin would you recomend?Thanks for the replys.:thumbsup:
 
#8
Keihin is a better carb that the mikuni. Yeah ok, Any evidence to prove that statement....Or is it really just personal opinion???jonnybiker
I base that statement on what I've been told by several motorcycle mechanics that have been in the business anywhere from 10 to 30 years.

I also base it on my experience & belief that Honda manufactures the highest quality Japanese motorcycle & only uses the best components for their products. It has been more than 20 years since I built any Japanese bikes, but I can't recall a single Honda with a Mikuni.

Why do Mikuni carbs regularly sell for about half of the equivalent Keihin?

I'm sure either will suit one of our mini bike engines just fine.

I've recently heard of a fairly new carb named OKO I believe. I have yet to look into it. Supposedly it combines the better features of both the Mikuni & the Keihin.
 
#9
....something about a spigot mount I guess thats the kind with the rubber manifold tube and clamps?Seems like an adapter would be easy to fab up for one like that.What size Keihin would you recomend?Thanks for the replys.:thumbsup:
You are correct. Instead of a flange with bolt holes. The carb just has what looks kind of like a hose bib.

Do you have a set of calipers? If so, measure the intake port I.D. in millimeters. Try to find a carb that size or a bit larger. Probably end up with something in the range of 16mm to 20mm. An 18mm might be perfect.
 
#10
You are correct. Instead of a flange with bolt holes. The carb just has what looks kind of like a hose bib.

Do you have a set of calipers? If so, measure the intake port I.D. in millimeters. Try to find a carb that size or a bit larger. Probably end up with something in the range of 16mm to 20mm. An 18mm might be perfect.
JM, I have to agree with you regarding the range of carbs that would work on the Briggs. I have a 22mm on my clone, and although it easily sustains the engine throughout the RPMs, I would think that if one can get a deal on a smaller carb (18-22) I would recommend buying it.
 
#11
I have a PZ-19MM Slide Carb in the closet for one of my builds ($25.00 Ebay). I found out that there is someone that makes intakes for these Carburetors, but they are $50.00 and up.

I think the bolt pattern is 1.890" or 1.900".
Common for Chiniese Pocket bikes.

Eventually I will make an intake from a pocket bike manifold when I find a used one or cheap one.
 
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