Planet Minis

burton88

i Just put a bbr exhaust on my tb88 with racehead. Is anyone out there running this same setup cause i cant get the jetting right. i keep getting the low end bog

SLOWPOKE

what carb and jets are you running?

burton88

im running the keihn 20mm basically the same as the shengwey. Today i tried 35 and 38 pilots with a 89 main and kept messing aruond with the needle.

bandit1911

I run a tb88 with ported head and the 20mm Shengway. Pilot is at 35. Main 95. Clip is one up from bottom. Runs great.

burton88

you dont have any low end problems? what kind of pipe u running

SLOWPOKE

steve, do you have an old or new style race head?

burton88

i have the new one. its ported too

SLOWPOKE

i would try a smaller pilot if you have one

burton88

alright, i have a 30 and a 32 i can try next weekend so hopefully that will fix thee problem

burton88

anyone else have any other suggestions for jet sizes and where the needle should be??

bandit1911

I run the BBR pipe. Small diameter

burton88

that doenst help me at all

lilskully

Have you tried reading the plug? If it is bogging as you try to give it throttle, you are probably too rich. I'm running a TB 88 kit with the older ported TB race head, and a 20mm Keihn carb. I tried a 85 main jet from the start, with needle in the center slot, and could not keep it running. I put the smallest jet I had...70..in and it was lots better. I read the plug, and it was a little white so I went to a 75 jet. It ran great at top end, but sputtered a little getting there. I then raised the needle 1 click, and I was home.
If it boggs when you twist the throttle, you are too rich.
If it sputters or backfires, you are too lean.

Pilot will adjust idle, and just off idle.
Needle will adjust midrange.
Main jet will adjust mid to top end.

As you ride, and it bogs, sputters, try pulling the choke lever a little. If your problems get better, you are too lean. The choke had richened the mixture to where it needs to be. On the other hand, if you pull the choke and it stays the same or gets worse, you are too rich, and you need to reduce fuel...smaller jet or lower the needle.

Good luck with it, and keep us posted.

MiniRacer959

try all the needle positions, there is like notches for them its a really easy job, i couldnt get mine to run good at all even with all different size jets and everything and i tried all the needle postions and i found the perfect notch for the needle, it runs like a champ now.

HRC

At least he was specific on what exhaust he is running. It's YOUR thread and you are looking for help and still haven't said exactly what exhaust you're running.

oilspot

Been running the tb88rh setup with a bbr pipe and been rejetting to try to get rid of the bog. Considered buying a different carb or mabey a manual clutch.
I got a different idea the other day... backpressure.
A stock crf50 baffle will fit a bbr pipe. And it gives it some backpressure. Just tried it today. No bog at all!!! Didn't spend a dime.
I had already put in the smallest pilot available. I've tried several jetting combos and my best combo still left the bike so it kinda ran like a 2stroke. You had to keep it "on the pipe" or it would sputter and fall on it's face.
With the stock baffle I can easily pick the front end up and carry it at almost any speed, even if running out of a tight corner.
I love my bike again!

reserectedmxr

You were asked earlier on what pipe you were using( include diameter ) hard to help if you don't give an the info that is needed to know.
Are you running the large diameter BBR pipe or the smaller diameter BBR pipe... that will greatly affect the back pressure. Stock silencer will fit in either BBR pipe and will gain you some back pressure and possibly solve your problem. The engine and carb dont run well without proper vacum and back pressure, get one wrong and it can make a real mess. Hope you get your problem solved quickly and easily.
Reserectedmxr-

bob123

lilskully explained it perfectly. You can try this site to show you how to. Minis to the Max