Carb id?

[lancerg89]

hey guys first post so bare with me im a newb. i just bought a 2001 blaster the things runs strong but theres some mix and match parts on it. i was told it was bored .20 over and has a dg pipe and the oil system is gone so pre mix the gas. my question is it came with a twist throttle which i know isnt stock and a mikuni carb. i have no idea wat the carb is from but the quad runs fine but when i push in the choke the thing revs to redline or will it idle by itself. there is a bunch of open vacum ports that i can blow air into should i cap these?. also i just ordered a stock thumb lever, do you think i should i get a stock carb to and start from scratch, i dont think the throttle cable on the stock line will thread into this carb. heres a pic of it please help thanks

 

[Blaner]

Welcome! welli wouldnt go back to the stock carb, they rather undersized (26mm Mikuni) im not too clued up with the different carbs but it looks to be something like a 30-something mm. maybe someone else can chime in with an eye for them. if it wants to revs with the choke in then its sucking air big time somewhere, dont ride it like that you will soon fry the top end. you should only have the fuel inlet and fuel overflow as openenings...its probably sucking air by one of the other openings you talking about.

 

[lancerg89]

ok well i pluged 3 lines and now it just revs all the way up the second i start. i noticed the other day it was idling fine, but then i turned the handle bars to the right and it shot up again im almost positive its a bad cable. the problem is i dont know what throttle i have and what carb to order a new cable for any ideas the twist in threaded part on both the twist throttle and carb are about a 1/16th smaller in diameter then the stock cable i have

 

[Awk08]

if i were you, and was considering a new carb, i'd start all over again, fresh
i'd go to ......................
Carburetor Parts Warehouse

get the number from there and call, the dude knows his shiat, and will sale you a carb, prolly jetted close to what you need, and a cable/thumb throttle to match

you could also check ebay for a used 28/30mm carb, then get a used stock thumb throttle and a cable to match

any bigger carb than that will require some finnese with the intake, or a new one of those also

but i defiantely wouldnt run it with the idle shooting to the moon and some half assed carb/throttle/cable set-up

 

[Blaner]

well if its skyrocketing when you turn the bars, you cable is too short! is probably never fully closed, get a longer cable! to test, unbolt your handle bars and let them lie down lower, then start the bike. dont forget to check your idle screws!

 

[lancerg89]

ok so i got to tearing apart the carb and i found out the [JOINT, CARBURETOR acording to the parts catalog] rubber boot with four bolts, that bolts to the intake manifold and the part where the other side of the carb gets clamped to intake is cracked all around where the clamp would sit. would allowing air to leak in there cause this spike?

 

[Blaner]

yes thats probably a big part of the prob! that air being sucked there is unaccounted for by the carb and it cant meter the correct fuel amount cause it hasnt passed through the carb. you should get yourself a leak tester for future use. just search a bit on here to find out more. im still convinced your cable is too short, with the turning bars story...

 

[royalt67]

I'm not a big mikuni guy but that is a flat-slide model, maybe a TX (should have a model number somewhere), so it is a performance carb and quite probably worth the time to get set up right. You will need a different cable than stock for the thumb throttle to aftermarket carb, whether mikuni or keihin. This one should work: CABLEFORTHUMBCONTROL...

Get that boot replaced! That is probably your entire problem with the over-rev / air-leak, so do it first.

Oh, and those nipples on each side, about mid carb are bowl vents! They must be open for the carb to work right. Normally you would have a tube coming off each one and hanging down with the line off the over-flow (bottom of bowl). The tube helps keep out water and dirt.

 

[lancerg89]

Thanks man that really helps I ordered that cable and the thumb throttle hope it all works

 

[royalt67]

Cool. Good luck!

Oh, and I think it is a TM carb. Check out this link http://www.sudco.com/Diagrams323728/exptm.gif There are also links to Sudco's catalog pages for TM carbs. They have excellent info here that should help ID it. Sudco International - Carburetors and Induction

 

[N8tsNastyBlasty]

first off ditch the twist it'll get u hurt.

looks like a mikunni tm style flatslide wich is a performance carb.get a tape measure or ruller and measure the i.d. Im a budget minded builder and made a coupler outta a 10mm bolt and a few a nuts. it will thread into a stock thumb throttle but has too much slack. I made a thread titled tm style to stock thumb throttle. If it is revving higher when u turn the handle bars check the cable routing and couplers. oil the shnot out the cable and make sure it opens and close good. Definitely replace the boot w stock or aftermarket one. then do a LEAKDOWN FOR SURE.

I run a 34mm on mine and it is nasty!!!!! Im still jetting but it's real close to dialed in.