MIKUNI VM26 Carburetor BETTER Idle Screw

NickThrash · 02-12-2017, 07:51 PM

I put the mikuni carb on my 250 Hawk and i love the better performance. The ONLY thing i dislike about the carb is how tiny the idle screw is and that it requires a screw driver to adjust it. The stock carb, for the hawk, had this big ass head on it that you could easily adjust with your fingers.

So i was wondering if anyone knew of a replacement that would fit the mikuni and also work similar or close to the original idle screw on the stock carb

Photos of both Idle Screws:

Stock.jpg

Mikuni.jpg

Merlin · 02-12-2017, 09:27 PM

I would like to know that as well.

NickThrash · 02-12-2017, 10:05 PM

I should also mention that a solution i had was to buy a small phillip's head screwdriver key chain. But it's still a big pain in the a*s to mess with the idle screw. Plus i cant tell you how many times ive dropped the damn thing trying to adjust the screw. I would just prefer something that would be permanently on there and simple to adjust.

Merlin · 02-12-2017, 11:46 PM

This should work:
http://www.ebay.com/itm/191539860297...%3AMEBIDX%3AIT

I just ordered one for my vm26.

pete · 02-13-2017, 12:12 AM

Do you have to adjust the idle that often yer need a big ass screw...
If so I think something needs looking at...

.

Sir kayakalot · 02-13-2017, 10:05 AM

I agree with Pete. If you're having to adjust the idle screw that much something is wrong.
I never have to touch mine and that's how I would expect it to be.

**JerryHawk250** · 02-13-2017, 10:16 AM

Quote:

Originally Posted by Sir kayakalot

I agree with Pete. If you're having to adjust the idle screw that much something is wrong.
I never have to touch mine and that's how I would expect it to be.

Same here. once I changed the jet, adjusted idle mixture and shimmed the needle I haven't touched it again.

Merlin · 02-13-2017, 10:19 AM

I just installed my carb and Iam adjusting it a lot. My old carb had an easy to adjust idle screw so i would like one for my new carb. Once I get it set up I hope to not have to adjust it much but going from 10,000 feet to 5,000 always seems to mess with my idle lol.

Bruce's · 02-13-2017, 12:18 PM

What about soldering or brazing a coin onto the end of it ?

mtiberio · 02-13-2017, 02:09 PM

Something to consider, some of those oversized idle or pilot screws add a lot of weight outboard of the threads in the carb, and can wag under vibration, and Waller out the threads over time.

NickThrash · 02-13-2017, 07:32 PM

Quote:

Originally Posted by pete

Do you have to adjust the idle that often yer need a big ass screw...
If so I think something needs looking at...

.

Usually only have to adjust it from a cold start, once the bike is warm/hot its all good. When im leaving my garage, sure its fine to adjust it and let it warm up on a higher idle. then lower it back down. but if i leave it parked somewhere for a while and get back on id have to mess with the throttle until the bike warmed up. Its winter and very cold right now and haven't been able to test it in warmer weather but i still like to be able to adjust things easily without having to have tools on me all the time

pete · 02-14-2017, 12:40 AM

Quote:

Originally Posted by NickThrash

Usually only have to adjust it from a cold start, once the bike is warm/hot its all good. When im leaving my garage, sure its fine to adjust it and let it warm up on a higher idle. then lower it back down. but if i leave it parked somewhere for a while and get back on id have to mess with the throttle until the bike warmed up. Its winter and very cold right now and haven't been able to test it in warmer weather but i still like to be able to adjust things easily without having to have tools on me all the time

sounds like the pilot jet maybe to small.... cold running while warming up is what the choke is for..

..

Ariel Red Hunter · 02-14-2017, 10:53 AM

Quote:

Originally Posted by pete

sounds like the pilot jet maybe to small.... cold running while warming up is what the choke is for..

..

Yes, I agree with Pete yet again. I agree the pilot jet is too lean. It is not normal to have to warm up an engine past a few seconds in order to get it to keep running. Here's my routine. Turn on the fuel. Apply full choke. Turn on ignition and start engine with the throttle no more than 1/8th open. Keep throttle open for a few seconds until engine will idle. Put on helmet. Set choke to halfway position. Put on gloves. set choke to off position, pull in clutch, put it in low gear, Ride off. ARH

old kid · 02-15-2017, 05:32 AM

you shouldnt have to keep adjusting the idle screw something else is not right , here is what works for me, with any mikuni single slide i always start with the needle clip in the middle slot, for a 250 class motor go with a 110 to 115 main jet and a 22.5 pilot. make sure the motor can breath, open up on the air box and allow it to draw air unrestricted, either modify the exhaust or swap it out for a less restrictive one. after the motor is at running temp have someone hold the throttle at around 2000 rpm and adjust the air intake screw to where the motor sounds the best, then you can set the idle screw where you want it and you shouldnt have to touch it again. mine will start on half choke in the cold i let it warm up for a few mins then go to open with no issues plenty of power through the low and high end.

ripcuda · 02-15-2017, 01:08 PM

I have a PZ30 carb with the large idle screw on my bike. It is easily adjusted with just my fingers. The choke pull on my carb is spring loaded and doesn't stay out/engaged unless I hold it open. So after starting with choke and a tad bit of throttle... I release the choke and use the idle screw to increase the idle (fast idle) while the bike is warming up from a cold start. This allows me to let go of the throttle and gear-up. I then turn it back to normal idle and away I go.

Cheers!

02-12-2017, 09:27 PM	#2
Merlin Join Date: Jun 2016 Location: Colorado Posts: 1,107	I would like to know that as well. __________________ Bashan Blaze Mods: Alloy Rim's, Muffler, Mukuni VM26 Carb, Foam Filter, Tachometer, Volt Meter,LED Headlight, LED Blinkers
	0

02-12-2017, 11:46 PM	#4
Merlin Join Date: Jun 2016 Location: Colorado Posts: 1,107	This should work: http://www.ebay.com/itm/191539860297...%3AMEBIDX%3AIT I just ordered one for my vm26. __________________ Bashan Blaze Mods: Alloy Rim's, Muffler, Mukuni VM26 Carb, Foam Filter, Tachometer, Volt Meter,LED Headlight, LED Blinkers
	0

02-13-2017, 12:12 AM	#5
pete Join Date: Jan 2012 Location: ChCh , NZ Posts: 2,262	Do you have to adjust the idle that often yer need a big ass screw... If so I think something needs looking at... . __________________ 09 XT660R ... 06 TTR250 ... 80 Montesa H6 125 Enduro... 77 Montesa Cota 348 MRR "Malcom Rathnell Replica"... Current resto projects.. 81 Honda CT110... 80 Kawasaki KL250A1... 11 Husaburg TE125 enduro... "sold" along with another 31... Lifan 125 Pitbike.. "stolen" ... KIWI BIKER FORUM...... http://www.kiwibiker.co.nz/forums/content.php All the best offroad rides in NZ... http://www.remotemoto.com/ E-mail... xtpete1@gmail.com
	1

02-13-2017, 10:05 AM	#6
Sir kayakalot Join Date: Dec 2016 Posts: 269	I agree with Pete. If you're having to adjust the idle screw that much something is wrong. I never have to touch mine and that's how I would expect it to be. __________________ Hawk 250 Mikuni carb 115 main. De-catted pipe. Air box mod. 15/42 sprockets. Digital instrument cluster, FMF end cap on muffler, handlebar toolbag, Custom foot pegs
	0

02-13-2017, 10:19 AM	#8
Merlin Join Date: Jun 2016 Location: Colorado Posts: 1,107	I just installed my carb and Iam adjusting it a lot. My old carb had an easy to adjust idle screw so i would like one for my new carb. Once I get it set up I hope to not have to adjust it much but going from 10,000 feet to 5,000 always seems to mess with my idle lol. __________________ Bashan Blaze Mods: Alloy Rim's, Muffler, Mukuni VM26 Carb, Foam Filter, Tachometer, Volt Meter,LED Headlight, LED Blinkers
	0

02-12-2017, 10:05 PM	#3
NickThrash Join Date: May 2016 Location: Ohio Posts: 154	I should also mention that a solution i had was to buy a small phillip's head screwdriver key chain. But it's still a big pain in the a*s to mess with the idle screw. Plus i cant tell you how many times ive dropped the damn thing trying to adjust the screw. I would just prefer something that would be permanently on there and simple to adjust.
	0

02-13-2017, 12:18 PM	#9
Bruce's Join Date: Apr 2015 Location: Sudbury ,Ontario Posts: 855	What about soldering or brazing a coin onto the end of it ?
	0

02-13-2017, 02:09 PM	#10
mtiberio Join Date: Jun 2016 Location: Arlington, VA Posts: 258	Something to consider, some of those oversized idle or pilot screws add a lot of weight outboard of the threads in the carb, and can wag under vibration, and Waller out the threads over time.
	0

02-15-2017, 05:32 AM	#14
old kid Join Date: Feb 2017 Location: NY Posts: 170	you shouldnt have to keep adjusting the idle screw something else is not right , here is what works for me, with any mikuni single slide i always start with the needle clip in the middle slot, for a 250 class motor go with a 110 to 115 main jet and a 22.5 pilot. make sure the motor can breath, open up on the air box and allow it to draw air unrestricted, either modify the exhaust or swap it out for a less restrictive one. after the motor is at running temp have someone hold the throttle at around 2000 rpm and adjust the air intake screw to where the motor sounds the best, then you can set the idle screw where you want it and you shouldnt have to touch it again. mine will start on half choke in the cold i let it warm up for a few mins then go to open with no issues plenty of power through the low and high end.
	1

02-15-2017, 01:08 PM	#15
ripcuda Join Date: Mar 2015 Location: Spokane, WA Posts: 253	I have a PZ30 carb with the large idle screw on my bike. It is easily adjusted with just my fingers. The choke pull on my carb is spring loaded and doesn't stay out/engaged unless I hold it open. So after starting with choke and a tad bit of throttle... I release the choke and use the idle screw to increase the idle (fast idle) while the bike is warming up from a cold start. This allows me to let go of the throttle and gear-up. I then turn it back to normal idle and away I go. Cheers! __________________ '20 TaoTao Hellcat 125 "grommet" '04 Yamaha TTR-125LE '00 Yamaha TTR-90 '07 Kinroad XT200GY Runmaster (sold) '07 KMD GY6 150cc ATV (sold) '07 Kangchao 250cc ATV Monster (sold) Baja Moto DB-30 "Doodlebugs"(x3) (sold) '06 Hi-Bird 200 parts bike (sold)
	0