Planet Minis

WOLFF777 · 01-28-2008, 02:24 PM

So I just picked up a TB stroker kit and I need to know what people are running for jetting on the Mikuni 26mm. I have the race head and classic honda big bore exhaust. It came with the 190 main but while it runs fine down low anything over 1/2 throttle make the motor act like its hitting a wall. Any suggestions?

filthyboatguy · 01-28-2008, 04:02 PM

165 main and go from there.

Grafixxs · 01-28-2008, 04:20 PM

We use a 150 main and a 15 pilot in our 124+R, so I think a 160 would be too much for a 108.

WOLFF777 · 01-28-2008, 05:24 PM

Quote:

Originally Posted by filthyboatguy

165 main and go from there.

2nd person to suggest this. That'll be a big jump but I'll prolly try it

BigBoreCRF · 03-15-2008, 07:11 PM

Ive got the same motor and it sounds like a similar problem. I have tried all mains from 155 to 195 and it seems to like the 190 best. It wont rev at all on the 155, and the bogging is really bad on the 165/175/185. With the 190, it runs great off idle, but will usually hesitate in the midrange for a few seconds before ripping on top. Ive moved the needle clip everywhere and settled on the bottom position for now. Air screw is 1 turn out. I'm looking for a place to buy a different needle and/or needle jet. Anyone know of a good place to find them?

dood · 03-15-2008, 09:06 PM

The problem is you have a carb that is too big for the size engine you are running.
You don't have a strong enough vacuum signal in your carb and that is why it's falling on it's face.
Does the bike run worse the hotter it get's? If so, it is too rich. Try pulling the choke to see if that helps. If it does, then you are too lean.
Select a main jet that runs the best WOT before you make any other adjustments.

I would try something like a 210 first to see if you are going in the right direction of jetting.

fatcaaat · 03-15-2008, 09:19 PM

Quote:

Originally Posted by Grafixxs

We use a 150 main and a 15 pilot in our 124+R, so I think a 160 would be too much for a 108.

Really? I run a 22.5/190 in my 124+R and it is perfect!

dood · 03-15-2008, 09:25 PM

velocity and signal strength will determine main jet size. Every engine is different even if they are the same parts from the same company. Fuel also plays a huge role too.

filthyboatguy · 03-15-2008, 09:47 PM

Quote:

Originally Posted by dood

The problem is you have a carb that is too big for the size engine you are running.
You don't have a strong enough vacuum signal in your carb and that is why it's falling on it's face.
Does the bike run worse the hotter it get's? If so, it is too rich. Try pulling the choke to see if that helps. If it does, then you are too lean.
Select a main jet that runs the best WOT before you make any other adjustments.

I would try something like a 210 first to see if you are going in the right direction of jetting.

That 210 will be a bit fat but wont hurt to try.

You need to find a 17.5 or 20 pilot, 1.5 turns on the mixture and run that clip in the middle for now. That with the 165 will get you close.

3 108s I run with run the 165, runs great.

filthyboatguy · 03-15-2008, 09:50 PM

Quote:

Originally Posted by WOLFF777

So I just picked up a TB stroker kit and I need to know what people are running for jetting on the Mikuni 26mm. I have the race head and classic honda big bore exhaust. It came with the 190 main but while it runs fine down low anything over 1/2 throttle make the motor act like its hitting a wall. Any suggestions?

Hitting the wall = fat main jet.

dood · 03-15-2008, 11:43 PM

Quote:

Originally Posted by filthyboatguy

That 210 will be a bit fat but wont hurt to try.

You need to find a 17.5 or 20 pilot, 1.5 turns on the mixture and run that clip in the middle for now. That with the 165 will get you close.

3 108s I run with run the 165, runs great.

Yer a roadracer who's not worried about bottom end performance so I can see running a carb that big on small engines.
Try that combo on a dirt bike, and the thing won't even get out of it's own way.
I know... I've tried it. Many times.

filthyboatguy · 03-15-2008, 11:48 PM

Quote:

Originally Posted by dood

Yer a roadracer who's not worried about bottom end performance so I can see running a carb that big on small engines.
Try that combo on a dirt bike, and the thing won't even get out of it's own way.
I know... I've tried it. Many times.

Yep............VM20 or TM24 work great on a 108 in the dirt.

BigBoreCRF · 03-16-2008, 09:23 PM

I was wondering about the vm26 being to big for the 108 since it is also sold with many of the bigger kits. It runs great except for that damn upper-midrange transition to the main, but then once its on the main it runs great again. I'm going to keep trying to get it dialed in, but Im starting to think you guys that say its too big for the motor are right. Anyway, thanks for the suggestions.

dood · 03-16-2008, 09:35 PM

Quote:

Originally Posted by BigBoreCRF

I was wondering about the vm26 being to big for the 108 since it is also sold with many of the bigger kits. It runs great except for that damn upper-midrange transition to the main, but then once its on the main it runs great again. I'm going to keep trying to get it dialed in, but Im starting to think you guys that say its too big for the motor are right. Anyway, thanks for the suggestions.

You need a different needle with a bigger root diameter and a sharper taper to help with the transition. Sudco will have it but honestly you'll have an easier time getting a smaller carb and selling your 26 to someone with a bigger engine ( or you could just save it til ya build a 124 )

BigBoreCRF · 03-16-2008, 09:42 PM

Quote:

Originally Posted by dood

You need a different needle with a bigger root diameter and a sharper taper to help with the transition. Sudco will have it but honestly you'll have an easier time getting a smaller carb and selling your 26 to someone with a bigger engine ( or you could just save it til ya build a 124 )

Yeah I found the sudco catalog yesterday. I gotta pull my needle out to see which one it is and then I'm gonna order a few to see if they help. About the vacuum strength, is there any way to improve it? I was wondering if a more restrictive intake or exhaust might help. I have a two bros air filter that is much smaller than the trail bikes that came with the kit. I'm going to try that to see if it makes any difference.

filthyboatguy · 03-16-2008, 09:43 PM

Have you tried the jetting I suggested?

TB sells the 108 kit with the 26 for a reason, it works great.

BigBoreCRF · 03-16-2008, 09:54 PM

No, I went to my local shop and they didn't have any pilots at all. I have tried the 165 with the stock pilot (22.5 I think?) and it ran well until the midrange - upper midrange where it ran roughly for a few seconds before cleaning out and running well on top. at first I thought it was too rich, so I moved the needle clip two slots leaner and it got worse. Thats when I started going up on the main and needle clip. The richer jetting helped with quick throttle openings and it did improve the transition, but the problem is still there. I've got the pilots ordered along with some other mains so I'll let you know what happens.

dood · 03-16-2008, 10:01 PM

Quote:

Originally Posted by BigBoreCRF

Yeah I found the sudco catalog yesterday. I gotta pull my needle out to see which one it is and then I'm gonna order a few to see if they help. About the vacuum strength, is there any way to improve it? I was wondering if a more restrictive intake or exhaust might help. I have a two bros air filter that is much smaller than the trail bikes that came with the kit. I'm going to try that to see if it makes any difference.

Restricting your intake and or exhaust will not solve your jetting issues. period.

highho04 · 03-16-2008, 10:21 PM

sorry to jack your thread but i am about to up my 88 to a 108 and what carb is the best 24 or 20???

dood · 03-16-2008, 10:23 PM

Quote:

Originally Posted by highho04

sorry to jack your thread but i am about to up my 88 to a 108 and what carb is the best 24 or 20???

TM32 jk

depends on what kind of riding you do.
Tight indoor stuff. 20
Fast out doors 24
RoadRace 26.

That's my opinion but others may say different.

01-28-2008, 02:24 PM	#1 (permalink)
WOLFF777 PM Newbie Join Date: Jan 2008 Location: MN Posts: 7	TB 108 Stroker VM26 - need baseline jetting So I just picked up a TB stroker kit and I need to know what people are running for jetting on the Mikuni 26mm. I have the race head and classic honda big bore exhaust. It came with the 190 main but while it runs fine down low anything over 1/2 throttle make the motor act like its hitting a wall. Any suggestions? Last edited by WOLFF777; 01-28-2008 at 05:23 PM.

01-28-2008, 04:02 PM	#2 (permalink)
filthyboatguy 3rd Gear Member Join Date: Oct 2004 Location: San Diego, CA Posts: 4,829	Re: TB 108 Stroker VM26 - need baseline jetting 165 main and go from there.

01-28-2008, 04:20 PM	#3 (permalink)
Grafixxs Old Fart Join Date: Apr 2007 Location: Marshall,MI Posts: 1,945 My Mood:	Re: TB 108 Stroker VM26 - need baseline jetting We use a 150 main and a 15 pilot in our 124+R, so I think a 160 would be too much for a 108.

03-15-2008, 07:11 PM	#5 (permalink)
BigBoreCRF PM Newbie Join Date: Feb 2005 Location: Elmhurst, IL Posts: 90	Re: TB 108 Stroker VM26 - need baseline jetting Ive got the same motor and it sounds like a similar problem. I have tried all mains from 155 to 195 and it seems to like the 190 best. It wont rev at all on the 155, and the bogging is really bad on the 165/175/185. With the 190, it runs great off idle, but will usually hesitate in the midrange for a few seconds before ripping on top. Ive moved the needle clip everywhere and settled on the bottom position for now. Air screw is 1 turn out. I'm looking for a place to buy a different needle and/or needle jet. Anyone know of a good place to find them?

03-15-2008, 09:06 PM	#6 (permalink)
dood 3rd Gear Member Join Date: Sep 2006 Location: Washington Posts: 3,055	Re: TB 108 Stroker VM26 - need baseline jetting The problem is you have a carb that is too big for the size engine you are running. You don't have a strong enough vacuum signal in your carb and that is why it's falling on it's face. Does the bike run worse the hotter it get's? If so, it is too rich. Try pulling the choke to see if that helps. If it does, then you are too lean. Select a main jet that runs the best WOT before you make any other adjustments. I would try something like a 210 first to see if you are going in the right direction of jetting.

03-15-2008, 09:25 PM	#8 (permalink)
dood 3rd Gear Member Join Date: Sep 2006 Location: Washington Posts: 3,055	Re: TB 108 Stroker VM26 - need baseline jetting velocity and signal strength will determine main jet size. Every engine is different even if they are the same parts from the same company. Fuel also plays a huge role too.

03-16-2008, 09:23 PM	#13 (permalink)
BigBoreCRF PM Newbie Join Date: Feb 2005 Location: Elmhurst, IL Posts: 90	Re: TB 108 Stroker VM26 - need baseline jetting I was wondering about the vm26 being to big for the 108 since it is also sold with many of the bigger kits. It runs great except for that damn upper-midrange transition to the main, but then once its on the main it runs great again. I'm going to keep trying to get it dialed in, but Im starting to think you guys that say its too big for the motor are right. Anyway, thanks for the suggestions.

03-16-2008, 09:43 PM	#16 (permalink)
filthyboatguy 3rd Gear Member Join Date: Oct 2004 Location: San Diego, CA Posts: 4,829	Re: TB 108 Stroker VM26 - need baseline jetting Have you tried the jetting I suggested? TB sells the 108 kit with the 26 for a reason, it works great.

03-16-2008, 09:54 PM	#17 (permalink)
BigBoreCRF PM Newbie Join Date: Feb 2005 Location: Elmhurst, IL Posts: 90	Re: TB 108 Stroker VM26 - need baseline jetting No, I went to my local shop and they didn't have any pilots at all. I have tried the 165 with the stock pilot (22.5 I think?) and it ran well until the midrange - upper midrange where it ran roughly for a few seconds before cleaning out and running well on top. at first I thought it was too rich, so I moved the needle clip two slots leaner and it got worse. Thats when I started going up on the main and needle clip. The richer jetting helped with quick throttle openings and it did improve the transition, but the problem is still there. I've got the pilots ordered along with some other mains so I'll let you know what happens.

03-16-2008, 10:21 PM	#19 (permalink)
highho04 2nd Gear Member Join Date: Dec 2007 Location: Kansas City, MO or Pleasent Hill, MO Posts: 754	Re: TB 108 Stroker VM26 - need baseline jetting sorry to jack your thread but i am about to up my 88 to a 108 and what carb is the best 24 or 20???

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