carb/kick start
6th Gear
Joined: Mar 2010
Posts: 10
Likes: 0
When the Keihin on my '79 finally wore out I put an S & S Super E on it. On a kicker you definitely want an accelerator pump. The S & S might not be such a great idea on the '71 though. Just too much carb for the engine though it will work with careful tuning. Don't expect great low end response. My '79 is about as close as you can get to a hand grenade. I am thinking about swapping the S & S out with the CV on my TC88 just for giggles, lol. I really think it is too much carb for the stock TC though.
Stellar HDF Member
Joined: Feb 2006
Posts: 3,035
Likes: 17
From: Houston Texas
With the Mikuni VM38 you will need this:
1) The carb
2) Throttle cable with the 90° elbow (gets the cable under the tank)
3) Rubber connector (connects the carb to the manifold)
4) Inlet manifold (fits against the heads and the carb end is round, rather than flanged)
5) Air cleaner assembly
6) Throttle twist grip assembly
This is the reason I recommend getting the carb as a kit, instead of buying it piecemeal. Because the carb sticks a bit further out than the Tillotson does, the air cleaner can become a pain to deal with.
The kit I bought had a special aluminum backing plate that came inward around the Mikuni. This lets the air cleaner assembly come inward, so it projects no more than an A/C on a Tillotson or Bendix carb.
See the pics of both sides of this backing plate below.....
One last thing...... Be sure to use a brace off the backing plate to hold the carb steady. Otherwise you run the risk of having manifold leaks from the carb sticking out in the breeze. This is true for whatever carb you are using. They all need this brace.
pg
1) The carb
2) Throttle cable with the 90° elbow (gets the cable under the tank)
3) Rubber connector (connects the carb to the manifold)
4) Inlet manifold (fits against the heads and the carb end is round, rather than flanged)
5) Air cleaner assembly
6) Throttle twist grip assembly
This is the reason I recommend getting the carb as a kit, instead of buying it piecemeal. Because the carb sticks a bit further out than the Tillotson does, the air cleaner can become a pain to deal with.
The kit I bought had a special aluminum backing plate that came inward around the Mikuni. This lets the air cleaner assembly come inward, so it projects no more than an A/C on a Tillotson or Bendix carb.
See the pics of both sides of this backing plate below.....
One last thing...... Be sure to use a brace off the backing plate to hold the carb steady. Otherwise you run the risk of having manifold leaks from the carb sticking out in the breeze. This is true for whatever carb you are using. They all need this brace.
pg
Thread Starter
|
Novice
Joined: Jan 2010
Posts: 17
Likes: 0
You say it's common..what is the problem with it. Do I just need to pull it apart and replace the insides? I've been looking around a bunch at different carbs. The mikuni seems to the be the carb of choice.
Banned
Joined: Sep 2009
Posts: 240
Likes: 0
The kick engagement system on XL relies on a few weak links.
For example........
The teeth on the back of the clutch hub wear readily.
The bush in the sliding gear gets loose.
That gear itself wears.
There are no "insides" as such.
Due to the age of many of the components, they can be well worn, if not previously, or recently, replaced.
In 1980, some folk were trying to recommend carbys from the 60's. stating they would never be bettered.
In 2010, some folk are recommending very outdated carbys, for a variety of reasons.
Some would be
Thats the only carby they know about.
They think their ideas are always best, and fail to move forward with technology.
You may well be happy with a very old design Mikuni. They were a good carby in their day.
But that day is long gone.
Given the cheap price of a good used CV, and their amazing performance and flexibility, they should also be considered, and, to my mind, probably well before a VM38.
But each to their own.
My own is not an old dirt bike carby though.
S7S E and Mik 42 all work well on Iron, but cost more.
For example........
The teeth on the back of the clutch hub wear readily.
The bush in the sliding gear gets loose.
That gear itself wears.
There are no "insides" as such.
Due to the age of many of the components, they can be well worn, if not previously, or recently, replaced.
In 1980, some folk were trying to recommend carbys from the 60's. stating they would never be bettered.
In 2010, some folk are recommending very outdated carbys, for a variety of reasons.
Some would be
Thats the only carby they know about.
They think their ideas are always best, and fail to move forward with technology.
You may well be happy with a very old design Mikuni. They were a good carby in their day.
But that day is long gone.
Given the cheap price of a good used CV, and their amazing performance and flexibility, they should also be considered, and, to my mind, probably well before a VM38.
But each to their own.
My own is not an old dirt bike carby though.
S7S E and Mik 42 all work well on Iron, but cost more.
Road Master
Joined: Aug 2006
Posts: 751
Likes: 6
From: 500 miles south from Artic Circle
The kick engagement system on XL relies on a few weak links.
For example........
The teeth on the back of the clutch hub wear readily.
The bush in the sliding gear gets loose.
That gear itself wears.
There are no "insides" as such.
Due to the age of many of the components, they can be well worn, if not previously, or recently, replaced.
In 1980, some folk were trying to recommend carbys from the 60's. stating they would never be bettered.
In 2010, some folk are recommending very outdated carbys, for a variety of reasons.
Some would be
Thats the only carby they know about.
They think their ideas are always best, and fail to move forward with technology.
You may well be happy with a very old design Mikuni. They were a good carby in their day.
But that day is long gone.
Given the cheap price of a good used CV, and their amazing performance and flexibility, they should also be considered, and, to my mind, probably well before a VM38.
But each to their own.
My own is not an old dirt bike carby though.
S7S E and Mik 42 all work well on Iron, but cost more.
For example........
The teeth on the back of the clutch hub wear readily.
The bush in the sliding gear gets loose.
That gear itself wears.
There are no "insides" as such.
Due to the age of many of the components, they can be well worn, if not previously, or recently, replaced.
In 1980, some folk were trying to recommend carbys from the 60's. stating they would never be bettered.
In 2010, some folk are recommending very outdated carbys, for a variety of reasons.
Some would be
Thats the only carby they know about.
They think their ideas are always best, and fail to move forward with technology.
You may well be happy with a very old design Mikuni. They were a good carby in their day.
But that day is long gone.
Given the cheap price of a good used CV, and their amazing performance and flexibility, they should also be considered, and, to my mind, probably well before a VM38.
But each to their own.
My own is not an old dirt bike carby though.
S7S E and Mik 42 all work well on Iron, but cost more.
It's true that modern carbs have better adjusments and you easier find parts for them.
In costwise CV is best and in other end there is Mikuni HS40 / HSR42.
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Banned
Joined: Sep 2009
Posts: 240
Likes: 0
You now have.......
A nice looking carby.
A nice fitting(and easily fitted) carby.
An easily tuned carby.
A rebuildable carby(if it ever came to that).
Access to all the spares and jets you could ever need.
There may be a little pain in the bill dept right now.....
but it will soon fade, while the quality of the job will go on.
Remember, poor man pays twice.
A nice looking carby.
A nice fitting(and easily fitted) carby.
An easily tuned carby.
A rebuildable carby(if it ever came to that).
Access to all the spares and jets you could ever need.
There may be a little pain in the bill dept right now.....
but it will soon fade, while the quality of the job will go on.
Remember, poor man pays twice.