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.

[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

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

Megadan, I received the new jets for my VM26 carb but havent yet had the time to install them. But I am confused about something. With my carb being a VM26 carb, arent these jets for a VM28 carb? Will they work on my VM26 when they say VM28? Thanks!!!!

[Megadan]

Originally Posted by HawkTwoFifty

Megadan, I received the new jets for my VM26 carb but havent yet had the time to install them. But I am confused about something. With my carb being a VM26 carb, arent these jets for a VM28 carb? Will they work on my VM26 when they say VM28? Thanks!!!!

These are clone carbs, not genuine mikuni carbs, so they dont follow any normal patterns.

[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

[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.

[Megadan]

^Your spark plug in that picture is in the range I like to call "factory good", which is how my Goldwings factory tuning is, along with many other bikes. It's in a safe range, but leaning very much toward the lean side of things. It's getting hot enough that the ceramic/electrode are getting cleaned almost back to white with just the slightest hint of tan. You could actually go a little richer and be ok. I have my Hawk tuned on the opposite end of the "good" spectrum, just a little rich but still stays clean. Closer to a light brown than a light tan covering the ceramic and electrode.

The real question is, at what throttle position is the plug getting in that condition? Was that after a WOT plug chop, or at low speed/idle?

[Musictrek]

Originally Posted by Megadan

^Your spark plug in that picture is in the range I like to call "factory good", which is how my Goldwings factory tuning is, along with many other bikes. It's in a safe range, but leaning very much toward the lean side of things. It's getting hot enough that the ceramic/electrode are getting cleaned almost back to white with just the slightest hint of tan. You could actually go a little richer and be ok. I have my Hawk tuned on the opposite end of the "good" spectrum, just a little rich but still stays clean. Closer to a light brown than a light tan covering the ceramic and electrode.

The real question is, at what throttle position is the plug getting in that condition? Was that after a WOT plug chop, or at low speed/idle?

I pretty much ran her up on the speed right before I got home. I think I should get her a little more rich. At least go to the 115 again.