Mikuni conversion

[DLDeere]

That's correct. Block the return line right at the gas tank. I plugged the gas line with a bolt. Others might have another idea.

[Mailman]

Well I got the fuel pump and carb mounted and hit the switch and it started right up and ran like a champ (inside) then after about three or four starts it started to boog down and didn't want to stay running, real heavy smoke and low rpm. I pulled the plugs RN3C and cleaned them, put them back in and no different. Once in a while it would rev up and run a little but then bog back down. Is there a rule of thumb for the settings for a jdx4 295. I got the carb from Matt and am useing the jets and setting that came with it Wondering if I will have to go up or down with some of the jets and which ones. Thanks

[Mailman]

Is anyone useing a Mikuni VM30 on a JDX4 or JD300 with the 295AX engine?

[400brian]

I'm betting smaller from what you are saying.

First, what's in it now for pilot and main?

If it idles good cold, but not when it warms up, it would indicate too big. Does opening or closing the air screw do anything?

[Mailman]

It's a VM30. Main is 270, pilot is 35, and slide is 2.0. It will start and run if you keep the throtle open but as soon as you release it. it will die. I have tried the air screw from 1 1/2 - 2 turns out from all the way in, and idle stop screw from 2 - 4 turns out from the carb. Like I said before when I first started it up it ran fine but after several times of starting it and then off it doesen't want to stay and idle.

[400brian]

I think a 25 pilot would be more in line. And the main will probably need to go down to the low 200s.

BUT, that is speculation on my part. You will most likely have to buy some jets and work your way down to where it runs, and the plug color is good.

[Mailman]

Thats what I was wondering about, I do have a 25 pilot but will have to get some lower main jets and some pilots in between. Thanks for the input anybody else feel free to jump in with your ideas.

[400brian]

Throw the 25 in, you won't hurt it any with a too small pilot. If the pilot is too small, it won't want to idle is all.

Remember; The air screw is backwards of most needle valves on carbs. It is metering air, not gas. So if you screw it out say 2 turns, you are leaning the idle mixture. If you screw it in, you are richening the mixture. If you have the correct pilot in the carb, the airscrew adjustment will make a difference in how it idles. if the pilot is way too big, the airscrew won't affect it much.

We have some data on running 34 mm Mikunis on 340s, if anyone has done a 30 mm on a 295 Kohler, speak up.

[S_Kyle]

For the 295 Kohler and a 34mm I believe we used a 220 main and a 30 pilot. Not sure how this would work for the 30 mm carbs

[Mailman]

Well I got my X4 going today I wound up putting a 200 Main jet, and a 20 pilot with a 2.0 slide and the E clip in the third grove from the top. The idle stop screw 3 3/4 turn out from all the way in and the air screw 1 1/2 turns out from all the way in. The plugs are a nice tan color but I didn't have time to check the exhaust joint by the muffler. This might not be perfect for all the X4's but at least it's a start and it really get's out and moves. By far better on acceleration than it was before with the Walbro carb. Thanks again for all the information and help on getting it switched over. Sandy Otte