Issue with Mikuni carb! Won't Start. Please advise.

[josealvrz11]

Hey everyone, I'm fairly new to this so your help would be greatly appreciated. I:I I bought a 91 blaster a while ago but, it has been given me a lot of starting problems and I left it sitting around for a good 7 - 8 months. Now I want to get back up and running. So I bought a rebuild kit for my Mikuni tmx 38mm carb and I was reading that it comes with a 370 main Jet and a 20 pilot jet. Is this good for this type of blaster? What are the standard levels for a blaster? If it is OK, what other things do you recommend I do to try to get back up running?

 

[blasterdude14]

that is a HUGE carb lol a stock blaster carb is only 26mm, and that jet will be way rich.

I recommend getting a smaller carb 28mm or 30mm OKO carb would be good, jet size about 140 maybe, if the jet sizes are the same as keihin

 

[brandoz28]

dude that carb is WAAAAY too big unless you've got a stroked big bore kit and some serious porting. i'm going to say that the pilot is so small that it can't get enough fuel to start it, BUT here's the usual rundown.

lets start with what you have checked. do you have spark? are the reeds ok? check the compression, have you removed the TORS?

 

[brandoz28]

that is a HUGE carb lol a stock blaster carb is only 26mm, and that jet will be way rich.

I recommend getting a smaller carb 28mm or 30mm OKO carb would be good, jet size about 140 maybe, if the jet sizes are the same as keihin

actually a larger carb will deliver less fuel to a small/inefficient motor than one that is sized correctly. it has to do with the amount of air velocity passing through the carburetor and the ability of that air to pull fuel out of the fuel bowl.

 

[josealvrz11]

that is a HUGE carb lol a stock blaster carb is only 26mm, and that jet will be way rich.

I recommend getting a smaller carb 28mm or 30mm OKO carb would be good, jet size about 140 maybe, if the jet sizes are the same as keihin

Yeah thats what I thought but, thats how I bought it and I'm still fairly new to this. What do you think I should do to try and run with it? Money is a lil tight right now.

 

[josealvrz11]

dude that carb is WAAAAY too big unless you've got a stroked big bore kit and some serious porting. i'm going to say that the pilot is so small that it can't get enough fuel to start it, BUT here's the usual rundown.

lets start with what you have checked. do you have spark? are the reeds ok? check the compression, have you removed the TORS?

I thinks it's bored but, don't know how much. I replaced the piston a while back too. But I don't know what size piston. I know it's a wiseco.

 

[josealvrz11]

dude that carb is WAAAAY too big unless you've got a stroked big bore kit and some serious porting. i'm going to say that the pilot is so small that it can't get enough fuel to start it, BUT here's the usual rundown.

lets start with what you have checked. do you have spark? are the reeds ok? check the compression, have you removed the TORS?

Sorry for my ignorance but, what is TORS?

 

[blasterdude14]

TORS is throttle over ride system
It messes up really often and can cause loss of spark and really bad bogging

 

[brandoz28]

do a search on here, get rid of the tors, that could very well be your problem if you just swapped the carb

 

[josealvrz11]

TORS is throttle over ride system
It messes up really often and can cause loss of spark and really bad bogging

How do you find out of it has TORS?

 

[brandoz28]

there's a box under the hood, and there are some wires that need to be removed. do a search, its been covered a lot

 

[blasterdude14]

well with the 38mm carb there shouldnt be any tors
but to check there is a little box that is mounted right above the cdi, trace the wires from that little box and see if they are connected to anything

 

[josealvrz11]

well with the 38mm carb there shouldnt be any tors
but to check there is a little box that is mounted right above the cdi, trace the wires from that little box and see if they are connected to anything

Yeah after looking at how to remove TORS article I don't believe it's installed.

 

[blasterdude14]

ok thats good then
well i recommend that you try to sell the 38mm carb and go down to at least a 28mm
Also have you checked for spark, are the reeds good?

 

[josealvrz11]

So after all this do you think the blaster can run OK with this setup?

 

[brandoz28]

its going to be really really boggy down low, if the bike is stock its going to run horrible. i'd try to sell it and get a smaller carb like bd said. something around 28-30mm

 

[josealvrz11]

its going to be really really boggy down low, if the bike is stock its going to run horrible. i'd try to sell it and get a smaller carb like bd said. something around 28-30mm

Where can I find a good one at a reasonable price?

 

[brandoz28]

ebay. the 28mm oko carbs can be had brand new for cheap

 

[josealvrz11]

ebay. the 28mm oko carbs can be had brand new for cheap

I searched ebay for it but, all 28mm OKO carbs are coming from Taiwan. Are those good?