Mikuni Swap on a John Deere 400 Snowmobile

[@TheYeti308]

Good One TCW ; You got the skills and patience to be a Great Carb Man . 👍

[@KevinMn1]

Nice job getting it dialed in!

[@briandemas2548]

You are smart! You know your carb tuning And are a master snowmobile tech. 20 years ago I would have hired you in a heartbeat! man I could have used you.

[@400brian]

I experimented with a Mikuni on a 340/5 15 years ago. I don't remember what needle jet or needle were in it, but I think I found a 25 pilot and a main of 210 or 220 was in the ball park. In the end I put the Walbro back on so I could have the airbox on it. The screaming Mikuni in your lap is not particularly pleasant. A properly functioning Walbro is a great carb. The problem at this point is that they are getting to be 50 years old, often corrosion has taken a toll, and the rebuild kits available now seem to make the carbs very fussy to get set up right. The advantage of the Walbro is the ability to easily adjust the carb to temperature conditions. As you stated, tuning a Mikuni for the early Deere sleds is trial and error, as the specs for the Deere sleds that used them do not work on the early engines.

[@tystahl]

Where can you get that rebuild kit

[@400brian]

@@tystahl New Breed Parts or Busco Bullet can probably supply you with whatever kit you want.

[@tystahl]

@@400brian is there anywhere I can get a new walbro carb

[@400brian]

@@tystahl These days they show up rarely on ebay. This series carb has been out of production for a long time.

[@GarageWorx]

Swapping a mikuni into my JD 400 has made it into an awesome running and starting machine.

[@jdullemond]

Awesome video thanks for sharing this with us

[@DarrellD.]

That sticker has got to be good for at least four or 5 miles an hour.

[@noahdale3356]

I have the vm34 for my 400 jd what jets and stuff I buy like ur end result

[@tystahl]

What did you do with the other line from the gas tank

[@twocylinderwill]

I pulled it back and cut it so there was about 2” of hose left on the tank. I then plugged it with a bolt and hose clamp to hold it tight

[@tystahl]

@@twocylinderwill I need to do this but I don’t have the skill, parts, or time to rejet a carb. I have a 1975 John Deere 300 and was wondering if I could get any old carb off of Amazon and just bolt it on

[@twocylinderwill]

From what I’ve been told, the knock off Mikuni’s aren’t great as they seem to have low quality control. Even to the point where genuine mikuni parts won’t fit in them. The 295cc in that sled might be hard to dial in as there’s not really a good starting point to reference from. You could get a VM30 and start with a pretty standard calibration and go from there as needed

[@the4thj]

We used to throw Walbros in the trash and use a Tilison add the glass ball, best we could find back then. But Mikuni is much better! Yeah, we had to piss with the cock we had too. Can you fix my 2005 Pol RMK 900? I just don't want mess with it the old ones seem easer.

[@twocylinderwill]

Tilly’s are great carbs once you understand them, I’ve got one on my Ski whiz! They don’t have to have their metering arm set within .001” like the Walbro does.🙄 Also sorry, 2005 is too new for my tastes lol

[@noahdale3356]

Can u send me what I need

[@twocylinderwill]

I can’t, but you can buy a whole kit from newbreedparts.com

[@williamjesse8357]

Nice job and great video, best swap you could had done as once the mukkni is set up the sled will run much much better and no more f..king adjusting it all the time

[@josephbrandt6778]

How long did you run it at what rpm to check plug burn and proper color?

[@twocylinderwill]

Really you should do it at a couple different throttle positions to check all along the carburetor range. 1/4, 1/2, 3/4 and Wide open. I had to cut a lot out of the video but 5 minutes of running at a given throttle position should give you a good read with plug color