125-200cc 2011 WR150 OWNER Keeping Mikuni 38mm Carb

man, that is a great tip! i'm always eyeing it thinking, 'is that thing level?' i have a good eye but doing it once with dartyppyt's trick and then mark/notch with gixxer's trick... i'm good to go from then on!

thanks guys

I've been using a line level like this for a long time also. I put a drop of red silicone on the boot to mark the very top. It has to be redone a few times a year though.

How I check and set my Mikuni TMXX float:

Take out the carb. Take off the bowl. Measure the height per the pics. Bend the tab as necessary.









The actual angle of the carb on this last pic is like the 2nd picture, the camera angle is skewed a bit due to me trying to measure and take a pic at the same time!

Good job! You should post up in 125 thread.

krieg,
Good photos of the float measurement...that should be made into a sticky!

Where did you get your aftermarket air screw and idle screw?

Air Screw: http://www.ziptyracing.com/products/product_detail.aspx?id=MTA5OA==

Idle Screw: I can't remember.

Krieg awesome pics bud! Hey I have the older 08 CR with I guess the TMX so anybody know where the measurement should be taken from and whatit should be? Yeah I agree this should be a sticky.

John,

You should send Ajaxauto a pm as he has had a lot of successful work with the TMX. Way back in a different life I believe I set my TMX to be parallel with the base and never had a problem once that was done. I used to routinely get 27-29 mpg with the TMX in my WR250 but just couldn't get it to run well at 4000' and then idle at 8000'+.

thanks for those pics, krieg!

utopia, here's that idle screw, it's a Stealth Racing unit. i've got one as well. still need to grab the ZipTy air screw

link to eBay store: http://tinyurl.com/3kj6r73

Will do Walt. The bike runs extreamly good but I have to cut the fuel off when it's on the triangle stand it will leak a little fuel out. Thanks.

If it runs out on a stand, then you need to adjust the float John, Mine wouldn't leak on a triangle, but it would leak at slightly greater angles. That's when I found it at a tad less than 6mm. I went to 7mm+ and it was a vast improvement.

Thanks Krieg with the pics you posted I should be able to give that a try.

Here is a link that will answer 90% of questions for anyone new to jetting
http://www.iwt.com.au/mikunicarb.htm

Raining here this morning as I was about to go riding so I had time to read the link you attached; very good info! Thanks for sharing. Now I'm going to print it so that I can get it to in-print into my brain.

I have had some major issues and they are still ongoing with losing fuel, i have changed the o-ring on float needle valve housing, set the height of floats to 7mm no good was loosing gas, then set it to 8.8mm and this cured the overflow issue but was pants once out of slower technical going, after about 15 secs wot thru gears i would get a bworb........ roll throttle on/off and would get a slight response back until back in techie stuff then fuel would catch up again, obviously float height too tight, anyhow i have had this problem b4 with a mik on a yz125 with large tank eventually solved it by trial and error, but this is way harder to get right:-(, so studied the float bowl and noticed 4 pre-drilled holes to allow fuel drainage thru removal of the large plug in base of float bowl, then realised that the lip inside of the float bowl where the the main jet sits is preventing about 15% of the float bowls capacity of fuel from actually entering this chamber where main jet sits in, so looked at plug with large o-ring on and drilled 4 holes in this to allow fuel drainage of fuel into float bowl into the main jet chamber, have reset float height to 7-8mm and its leaking still when on stand, so gonna put it back to 8.8/9mm and with the extra fuel released from mod this may well cure the whole issue, i know why the lip is there initially to hold any crap that manages to get into float bowl(whenever i have serviced this carb (50hours use),i have never found any crap in it, i think this will work.

I drilled mine out too and was able to get the floats set at a tick more than 8mm and not run out of fuel on WOT runs.

Pictures?

Here you go

Thanks for that. I've got my jetting and float level perfect and have checked fuel flow from my tank and it's more than sufficient so I will be doing this mod next... It can't hurt anything so why not.

OK, I have done some testing today after the mod, and with float height at 9 its pants(fuel starvation pretty quick), so sat down and had a good hard think, then took float bowl off AGAIN, put the carb upside down at 45degrees in vice, then lowered float tab onto fuel metering valve to just bearly sit on it, and then set the float height at 8mm, put back together, fuel on, lent bike over to left and at 45degrees fuel started to overflow(looking good), went for a test run, and ITS NOW MEGA absolutely spot on, smooth transition from bottom to top on throttle, no issues rolling off from WOT, cut the plug after 1 mile of WOT and perfect colour. So now the jetting is right in relation to fuel supply, and has the distinct husky 2-stroke ballistic note!