Carb questions
 

Hey,

I have just removed the carb from my 4PT to give it an overhall and was wondering if anyone can answer a few questions.

Is this the same carb as the one depicted in the Clymer manual on the 3AJ. There are no markings on it apart from manufacturers name which I forget (YBIS?). From the pictures in the manual it looks like the same one but I know it must be slightly different as it has a choke lever on the side rather than with a cable.

Also does anyone know how best to remove it. In the end I had to loosen the air box and remove the left hand side cover which I don´t think was a good idea as it was glued on as well as screwed. There seems to be a lot less space than shown for the 3AJ.

It also has a fat tube coming off it with a plastic chunky thing on the end which looks like it should connect into somewhere behind, but wasn´t. Any ideas?

Is it necessary to seperate the two carbs for overhaul or is it better to leave them together.

Which is the best solvent to use to clean it, I was thinking of parafin which is hard to find here or meths.

Does anyone have a manual of any kind that covers the 4PT carb?

Any other tips greatly appreciated.

Many thanks,

Finian

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I cannot answer your questions, sorry, but a little info that may help you track down a link?

I think the carburetor is most probably made by Teikei, for Yamaha? YDIS stands for Yamaha Duo Intake System and I would think any instructions would be very similar across the ranges. Your model is younger than most, and so any difference would likely be a better refinement only.

For your information, I believe the Clymer Manual stops short of the 3AJ model you refer to.

Good luck.

hi finian,
ive taken the carbs out on my 4PT(1997 XT600E) a few times, i think you do have to loosen the airbox and pull it back a bit, theres not a lot of room, is there? ive also got the clymer manual and i didnt find anything much different to the carbs in the pictures. the choke is just a cable that runs down to the knob we have in the 4PT.

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dave

Thanks for the reply guys.

Dave, do you know what the tube coming off with the chunky plastic thing on the end is? Which solvent did you use to clean the carb.

Thanks,

Finian

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that tube ends with a small air filter.
it provides access of atmospheric pressure to the space above the diaphragm in sec. carb to enhance throttle response.
use only fuel to clean the carb.
use pressurized air to clean the inside of the carb.
carb manufacturer is teikei. the excact version of your carb is printed on the right side of the prim. carb float bowl.
since 1987 this carb has remained more or less the same.
it is a very simple and easy to understand carb.
part lists and drawings here:
http://216.37.204.202/Yamaha_OEM/Yam...p?Type=12&A=20
a detailed description of how the carb works you can find here (but only in german):
http://www.xt600.de/xt_werkstatt/+sp...r/vergaser.htm

regards
klaus

finian,
i got a can of aerosol carb cleaner from halfords, cant remember whats in it i think it was a mixture of very high grade petrol and liquid propane(propellant). i pointed the nozzle up the floatbowl drain tube and undid the tiny drain screw a couple of turns and squirted.
i then got the drain screw in my eye and a face full of carb cleaner, of course id undone the drain screw too much! it then took me and my wife four hours to find the screw somewhere on the garage floor, honestly, it was like something out of a carry on film!! i can laugh now, but that stuff bloody hurt like hell!

i know the carbs are a pain to take out but it is much easier to clean them on a workbench and you do a much better job, i used the lovely carb cleaner and a 1/2" paintbrush (learn again from my experience, buy a good quality brush that does'nt lose hairs everywhere).

i was surprised how "gummy" my carbs were for quite a young bike. also, that carb cleaner was expensive so if klaus says use ordinary fuel, go for it!

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dave

PS as klaus said its a very simple carb, dont worry about taking it to bits to clean out the jets and filters etc but make sure each bit is spotless when it goes back in!

[This message has been edited by DAVSATO (edited 11 May 2003).]