Hawk 250 Mikuni 30mm Carb Jetting Land Elevation of 600 Feet

[HawkTwoFifty]

I just bought a MIKUNI VM26 Carburetor 30MM carburetor for my new Hawk 250 and was wondering what carburetor jets and carburetor settings have proven to be ideal for those who use this carburetor at or near 600 ft above sea level.

I am hoping to have the jets and settings to this 30mm carburetor as near to perfect as possible before installing it onto my bike. If anyone has any input on this, I would appreciate it. Thanks!!

[HawkTwoFifty]

Also, I just ordered an an after-market exhaust (the one that is popular here and recommended by experienced Hawk 250 owners here) and was wondering what jetting and settings would also be necessary for the Hawk 250 for the 30mm carburetor in addition to this exhaust when/if I do install it. Thanks!!

[Megadan]

Elevation and air temp play a role.
First, I highly recommend genuine mikuni jets and not the cheap kits.

I am at 1000ft elevation. Full exhaust and a pod filter. I run a 27.5 pilot jet and in the summer a 117.5 main, with a 120 main currently in the cooler months. I run with the needle in the middle slot or 1 notch down from center.

Many others run close to the same jet sizes. Pilots anywhere from 25 to 30, mains between 115 and 120 with full mods.

For a stock bike, a 25 pilot and a 110 main with the needle in the center eill get you close. Some adjusting of these sizes is still recommended as every engine can act a bit differently.

[Ariel Red Hunter]

Originally Posted by HawkTwoFifty

I just bought a MIKUNI VM26 Carburetor 30MM carburetor for my new Hawk 250 and was wondering what carburetor jets and carburetor settings have proven to be ideal for those who use this carburetor at or near 600 ft above sea level.

I am hoping to have the jets and settings to this 30mm carburetor as near to perfect as possible before installing it onto my bike. If anyone has any input on this, I would appreciate it. Thanks!!

Congrats on buying the VM-26 Mikuni. You will find it easy to tune. One suggestion; only buy genuine Mikuni jets. They are much more accurate than the other brands...ARH

[HawkTwoFifty]

Originally Posted by Megadan

Elevation and air temp play a role.
First, I highly recommend genuine mikuni jets and not the cheap kits.

I am at 1000ft elevation. Full exhaust and a pod filter. I run a 27.5 pilot jet and in the summer a 117.5 main, with a 120 main currently in the cooler months. I run with the needle in the middle slot or 1 notch down from center.

Many others run close to the same jet sizes. Pilots anywhere from 25 to 30, mains between 115 and 120 with full mods.

For a stock bike, a 25 pilot and a 110 main with the needle in the center eill get you close. Some adjusting of these sizes is still recommended as every engine can act a bit differently.

Thanks Megadan for the great info! Can you please tell me if this is this is the pilot jet that you have for your Mikuni VM26 30mm carb? https://www.amazon.com/Genuine-Mikun...26+mikuni+30mm

[Megadan]

Originally Posted by HawkTwoFifty

Thanks Megadan for the great info! Can you please tell me if this is this is the pilot jet that you have for your Mikuni VM26 30mm carb? https://www.amazon.com/Genuine-Mikun...26+mikuni+30mm

No. You want a vm28/486 pilot jet.
https://www.jetsrus.com/a_jets_by_ca...-486_pilot.htm

[HawkTwoFifty]

Originally Posted by Megadan

No. You want a vm28/486 pilot jet.
https://www.jetsrus.com/a_jets_by_ca...-486_pilot.htm

Thank you Megadan. I have Amazon Prime so I was looking at the pilot jet at this amazon link to buy. This pilot jet looks correct with the one you have, right? Thanks!!

https://www.amazon.com/Genuine-Mikun...F486+pilot+jet

[Megadan]

That is the one, yes

[HawkTwoFifty]

Originally Posted by Megadan

That is the one, yes

Thanks Megadan, one more question... would you have any idea how much higher or lower I should go with the pilot and main on the new VM26 carb before I run the exhaust and filter pod?

I was planning to re-jet my new VM26 carb before I install the exhaust to allow me to see the power difference each modification makes. So I would start out with running just the VM26 carb on a stock bike for now and was wondering if you would know how many sizes either upward or downward on the pilot and main would be decent to start experimenting with. Do you remember what jets came in the VM26 carb from the factory? Thanks!!

[Ariel Red Hunter]

Originally Posted by HawkTwoFifty

Thanks Megadan, one more question... would you have any idea how much higher or lower I should go with the pilot and main on the new VM26 carb before I run the exhaust and filter pod?

I was planning to re-jet my new VM26 carb before I install the exhaust to allow me to see the power difference each modification makes. So I would start out with running just the VM26 carb on a stock bike for now and was wondering if you would know how many sizes either upward or downward on the pilot and main would be decent to start experimenting with. Do you remember what jets came in the VM26 carb from the factory? Thanks!!

With the stock exhaust a 105 main and a 22 pilot has been reported as working well. IIRC, the carb comes with a 95 main jet.

[HawkTwoFifty]

Originally Posted by Ariel Red Hunter

With the stock exhaust a 105 main and a 22 pilot has been reported as working well. IIRC, the carb comes with a 95 main jet.

Thanks Ariel Red Hunter!!

[Sullybiker]

I'm at around 800ft and I ran 27.5/110 when I had the OEM exhaust on, needle clip one detent down from the middle. Without the needle clip change I got a flat spot just around 1/4 throttle.

With the ebay exhaust I changed the main to 115, runs fine, pulls well all the way through. Slightly rich at idle (I don't think I've had to use the choke since forever) but I'm happy with it.

[Megadan]

My Mikuni came with a 20 pilot and a 100 main. Others have reported a 95 main, but the same pilot.

As far as stock vs. Modified. My pilot jet with no mods and with a pod filter and exhaust never changed. It was a tad rich on the stock bike, but only just. A 25 pilot worked, but was just a tiny bit lean and would cause minor stumbles at very light constant throttle/ Since the bike is air cooled, I chose to go with the slightly rich option. With the intake and exhaust, it very slightly leaned up, but not enough to warrant a change as it is still just a tad on the richer side of things.

The biggest changes with the intake and exhaust will revolve around the main jet and needle position. Dial in the main jet first, then adjust the needle position as needed to dial in the 1/4 to 3/4 throttle fueling.

The only other change I had to make was with the idle mixture setting after adding the intake and exhaust. I had to give it about an extra 1/8th turn out.

[pistolclass]

Mine was shipped with a 98/20.

[Musictrek]

I recently put the aftermarket ebay exhaust on mine. I'm using stock air box and a K&N filter with Mikuni VM carb. I'm at 1250 elevation. I'm currently still on the 110 main and 20 pilot and clip at full rich. The bike seems to be running great! the low end pickup is strong. 0 up to 60mph seems good and very quick. But, I occasionally get a hiccup maybe midrange. I checked my plug and its not super white or wet that's for sure (image attached). Maybe a sandy brown. I haven't put too many miles on the bike though with the new pipe. I originally modified my oem exhaust by removing the cat. I went to a 110 main and left the pilot stock on the Mikuni carb for the OEM pipe setup. On that config it did have a hiccup within the throttle range but I liked the way it ran. The clip is at full. I remember going to a 115 main and 22.5 pilot on the stock exhaust K&N filter and Mikuni carb. It seemed to run ok at 1250 elevation but maybe slightly rich. I cant say it was an improvement. When I climbed the mountains with that setup it really got rich at 2800 feet up. I went back to the 110 and 20 pilot and left it that way. So, I added the new pipe recently like I mentioned and the bike definitely has better power pickup and speed but the occasional hiccup. But even that is not a given every time kinda thing. Its just how the throttle is used. Its not a show stopper for me. If I have time, just for kicks I may put the 115 main in. That's what I like about the bike. I can mess with it. The bike starts without issues. That is a real joy on that. I would have thought that going to the new pipe the bike would not run that great with the setup I had been using with the OEM pipe. But, it actually is running better. Not perfect but better.