alright so i just installed my tb 88 kit with race head, went to fire this thing up and I'm having nothing but issues with my carb tuning. IT JUST COMPLETELY SUCKS. started with what the kit provides for a main and pilot which is 89 main, 35 pilot. have been reading up on this rich bog, and turns out I'm having it as well! this bog just doesn't want to go away... i broke down and bought a bigger pilot, and am now at a 38 pilot. still have this bog and have been going 1/4 turns on my air screw to try and work it out. i can't seem to get this 20mm sheng way to tune up to what i want. I've tried every main jet that comes with this kit, 82-95... nothing is changing and yes I've messed with all needle clip positions while doing this. where do i go from here! i want to be able to one out of a turn and whack it, and have this thing stay right with me. do i go with a mikuni or a kiehen? SOMEONE PLEASE HELP! I'm losing sleep over it! :roll: THANKS!!
TB 88 kit RH carb tuning issues......
nickbeers
1 - 18 of 18 Posts
alright so i just installed my tb 88 kit with race head, went to fire this thing up and I'm having nothing but issues with my carb tuning. IT JUST COMPLETELY SUCKS. started with what the kit provides for a main and pilot which is 89 main, 35 pilot. have been reading up on this rich bog, and turns out I'm having it as well! this bog just doesn't want to go away... i broke down and bought a bigger pilot, and am now at a 38 pilot. still have this bog and have been going 1/4 turns on my air screw to try and work it out. i can't seem to get this 20mm sheng way to tune up to what i want. I've tried every main jet that comes with this kit, 82-95... nothing is changing and yes I've messed with all needle clip positions while doing this. where do i go from here! i want to be able to one out of a turn and whack it, and have this thing stay right with me. do i go with a mikuni or a kiehen? SOMEONE PLEASE HELP! I'm losing sleep over it! :roll: THANKS!!
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532 Posts
Never going to go away. I even bought a keihin pc20 & it's the same. You just got to roll on the throttle.
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720 Posts
been having the same problem with mine since day one.....just glad im not the only one...
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532 Posts
I read, I changed jets, then I did it again & again. Then I bought a real pc20 & changed jets, then again. Then I said f%*k it & just learned to ride around it. Just have to roll on from the bottom & once you have some rpms you can't tell. No accelerator pump & 2 extra strokes, just have to live with it.
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4,902 Posts
ive never had a chinese carb but you should be able tune the carb if its a 4stroke carb theres some carbs out there that are made to run 2stroke thats the only thing i can think of unless something else on the bike like ignition timing or cam timing is off
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585 Posts
You usually can't tune that bog away because these carbs don't have accelerator pumps like the big bikes. So when you whack the throttle wide open at low rpm, the carb just can't supply the fuel fast enough thru the jets.
You only really notice this bog when you're free revving the bike. If you can feel this bog when you're riding, then yeah you need to work on the tuning more. But you should be able to tune it so you don't notice while riding.
You only really notice this bog when you're free revving the bike. If you can feel this bog when you're riding, then yeah you need to work on the tuning more. But you should be able to tune it so you don't notice while riding.
also, i cannot get this thing to lean out. at all. I've dropped it to the lowest main and smaller t pilot i got... 82, 30... and plug is still black, but i should probably get a new plug and try it because i guess once they are black, they never clear back to a white or brown color....any advice as to whats making this thing so rich?
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532 Posts
I'm running a 90 main, 38 pilot, needle in the middle. My plug is black too but it won't pull as good with a smaller main. If it runs good I'd go by that.
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720 Posts
im getting the 108 stroker crank and 26mm carb and see if it still bogs. also a manual clutch possibly.
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6,011 Posts
What your ask'n from a small bore .. , high rev'n ...., high flow race head kit can be done .., but you will lose some top end to get it ...... For you to get the low end power you want from a race head kit ..., you really need a smaller carb ..
But if you really want ta keep what ya got for a carb ? Then here's my take ....
IMO - Your still too rich down low ... I would first run the smallest main jet you have , with the smallest pilot jet you have .... , drop the needle so its all the way down into the carb .. Then adjust the air screw to where it run'n clean at a 1/4 throttle and see what you've got ...
IMO - If you have the extra cash ??? A stroker crank will give you the low end pull you want to match the carb you have installed ..
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10,917 Posts
Quick Tips For Small 4-Strokes
Please test ride the bike , you cant jet / tune a bike sitting on the stand !
YOU DO A PLUG READ WITH A NEW PLUG
Please test ride the bike , you cant jet / tune a bike sitting on the stand !
- If it boggs or dies right off from an idle when you turn the throttle, your pilot is too lean.
- once its clean off an idle your done with the pilot move on to the main and do a plug read
YOU DO A PLUG READ WITH A NEW PLUG
- We offer even Larger pilots NOW that cure this ...
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720 Posts
so if i order a crank and bump my 88RH to a 108 would i still need to bump up from a 20mm carb to a 26mmcarb that TB recommends? or just buy the crank and go from there depending on how it runs....
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10,917 Posts
You can run the TB20 with a stroker
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720 Posts
i have this guys same problem...and when i went up in jet sizes it ran worse....honestly from what i've read and witnessed with the problems on the botom end bog i just wouldnt buy the RH without the stroker crank....just my 2 cents
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6,011 Posts
No .., do not get the 26 mm !!! You will most likely run into the same problem you are in now with that low rpm bog ...
The problem i've seen . is when run'n really large carbs on small bore motors ... , you need to ride em in the higher rpm's .. Otherwise they bog down at low rpm's ...
If you love the power of an 88 and don't want anymore ?? Then I would just run an smaller carb 16 or 18 mm ...
I know KLX 110 carbs are 18mm and are cheap to had on here from time to time ... I've heard that they will work on a 50 manifold ... But I'm not sure exactly what it takes to do so ?? If you need to run the KLX throttle cable and throttle tube assembly too ???
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10,917 Posts
Main or Pilot ?
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10,917 Posts
GETTING STARTED GETTING A NEW CARB
Here is how to get started:
READ the jetting guide
TBolt USA Tech Database - TBolt USA, LLC
Set the adjustment screws to 1.5 turns out
(2.5 out on bottom fuel screw 22mm mikuni)
Bolt the carb on
If it bogs off idle go up on the pilots till it stops and comes clean off the idle
Do a plug read
Go up or down mains till its close to Tan / light brown
Fine tune with the Needle
Fine tune with the air - idle - fuel screws
Go riding
Here is how to get started:
READ the jetting guide
TBolt USA Tech Database - TBolt USA, LLC
Set the adjustment screws to 1.5 turns out
(2.5 out on bottom fuel screw 22mm mikuni)
Bolt the carb on
If it bogs off idle go up on the pilots till it stops and comes clean off the idle
Do a plug read
Go up or down mains till its close to Tan / light brown
Fine tune with the Needle
Fine tune with the air - idle - fuel screws
Go riding
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