86kxt carb fitment question

[phantomtracer]

I purchased a new mikuni 34mm carb and just noticed it is too short when trying to mount the stock airbox, does anyone have a good stock carb to sell or recommendations on another new carb that will fit?


Sent from my iPhone using Tapatalk

[jeswinehart]

How short is it Phil ?
I have sevral of our aluminum face plates that I use in making intake boots that can also be used as a spacer plate between intake boot + jug. It will gain you 1/4 inch in length.

[christph]

A reed spacer is also a solution. They are about 1/4 inch and will give you a little boost on the bottom end and mid range. I use one on my 84 and 87 Tecates.

[barnett468]

.
Happy New Year Phil and others.

Here's the deal . . That bike came with a 34 mm oval bore carb . . The oval bore improves bottom end and that carb works killer on there . . Since you are not running the horsepower killing stock muffler/silencer, you will gain some mid and top power if you run a 36 mm carb but you will loose some bottom end . . In other words, it will bog a little if you open the throttle all the way at low rpms.

A spacer between the reed and cylinder will "soften" the power band a little, so if you like it to hit hard and rev far, I would not use one there, however, installing one between the reed and the boot will have far less affect . . If the same spacer will work in both places, you could try it in both locations to see which one you prefer, but if you want it to be scary, use a 36 and no spacer between the cylinder and reed block.

I wouldn't use a spacer between the cylinder and block that is more than 1/4", so if it ends up that you must use a thicker spacer, you can run a 1/4" one on both sides of the reed block or a 3/8" one between the block and intake boot . . Also, you can bump the compression up a little without the stock muffler if you want even more power.

imo, if someone wants a bike with less power, they should buy an atc250r . http://www.mustang.org.au/forum/Smileys/smilies/bolt.gif

[jeswinehart]

PM me if need one or more. My cost is 7 dollars each so that would be your cost (+ what ever shipping)

[phantomtracer]

The issue with a spacer is it will raise the intake boot upward a bit and that will cause fitment issues. I would need to space it 3/4" which I do not feel comfortable doing. Thank you for the suggestions, I'm hoping someone can tell me of a new carb that will fit. I will post measurements soon


Sent from my iPhone using Tapatalk

[barnett468]

.
If you can not find another carb that is long enough, you could make a sleeve for that one which could simply slip over the air cleaner side of that carb which could either be JB welded on [fancy, I know] or be thick enough on the carburetor end to install an o ring in to seal out dirt when it was pushed over the carb or you probably have just enough room to put a 5/8" long piece of rubber tube over the end of the carb, then install an aluminum metal tube tube into it to use an extension of the carb bell that buts up against the carb which is 7/8" long . . this will go into the air box far enough to get a good seal and if you use narrow carb type clamps, it won't look too hokey.

As far as an orig carb goes, I would try Ebay plus send nd4speed a pm, because he has a few Gen II TECATE trinkets sitting around.
.

[jeswinehart]

Wow, 3/4 of a inch. That is quite a "stretch" !

[phantomtracer]

So I think I found the problem, the airbox must be a bit deformed which is not allowing the airbox to rotate. I think if I hit it with a heat gun it will be ok. Barnett that is exactly what I was thinking of doing. If anyone can measure the overall length that might confirm my thoughts. My carb measures 92.25mm. Thanks


Sent from my iPhone using Tapatalk

[barnett468]

.
I don't think there are any new aftermarket carbs that will be long enough, however, a vintage EI or Lectron carb should be, unfortunately, most of those have a 4 stroke style needle jet, so you would need to see if a 2 stroke needle jet from a later style Lectron would fit, plus you might have to change the air jet sizes so it's a bit of a gamble and a hassle.

This has a long bell which is one of the things I mentioned that you could do to yours somehow.

This is an EI carb and all of them were blue, but it is nearly identical to the Lectron because the same person designed both of them.


................................. http://i79.servimg.com/u/f79/13/49/48/64/carbur23.jpg

[John_Neary]

I was looking at using one of these 38mm Mikuni carbs on my Rotax since it would help the air cleaner stay on as well as its something i understand how to jet, unlike the Lectron while still being period correct for a 1984 bike. Should give you the length you require.

225933

This chap will even prejet the carb for you or let you pick the jets, slide and needle of your choice.

http://www.ebay.com/itm/Maico-Husqvarna-Bultaco-Round-Slide-38mm-Mikuni-Carb-WITH-YOUR-JETTING-NEW-/151567719376?hash=item234a23dbd0:g:~4EAAOSwVFlT85E-&vxp=mtr

[barnett468]

So I think I found the problem, the airbox must be a bit deformed which is not allowing the airbox to rotate. I think if I hit it with a heat gun it will be ok. Barnett that is exactly what I was thinking of doing.

If you have a lot of experience doing that you will be ok, but if you don't, Ii suggest you use the low setting and take it slow by not holding it too close, because once that particular plastic gets near the point where you can reshape it a little, it only takes a hair more heat to reshape it into a nice puddle of molten plastic.

Another safer option is to boil water in a big pan hen hold the area you need to reshape in the water for maybe 10 seconds at first then try it . . If the affected/damaged area is small enough, you can use the steam from a Tea Kettle or pressure cooker etc but be careful not to reshape your hands in the process.

Also, after you reshape it, you can quickly dip the heated area under the faucet while you hold it in the correct shape and this will instantly freeze it into that shape.

[christph]

Here are some pictures of my 87 Tecate with a reed spacer. I had no fitment issue but then again I am running a Keihin. The Mikuni TMX is a narrow carburetor but I know they sell air boot adapters. Here is a link to what I am referring to: http://www.nichecycle.com/ncs/mikuni/accessories/tmx-001-tmx-tms-air-boot-adapter-30mm-by-mikuni.html

225941225942

[barnett468]

Here are some pictures of my 87 Tecate with a reed spacer. I had no fitment issue but then again I am running a Keihin. The Mikuni TMX is a narrow carburetor but I know they sell air boot adapters. Here is a link to what I am referring to: http://www.nichecycle.com/ncs/mikuni/accessories/tmx-001-tmx-tms-air-boot-adapter-30mm-by-mikuni.html

225941225942

LOL, well I guess he doesn't need to make one then . . Xlnt find and hopefully it seals well enough to keep sand out.