fan cooled 440 running bad at higher than idle

afponiky · Post by **afponiky** » Wed Dec 06, 2006 10:41 pm

I can get the 340 (which has a 440 fan cooled engine) running on the second pull. It will idle good, and run but when I give it gas (the tach maxes out then) it will sputter and I hear popping in it. It will not run smooth and blows alot of smoke.

What should I be looking for? I sprayed carb cleaner around the seals, and starting fluid, no change.

There only seems to be one adjustment screw on the carb, I think it is junk, I have cleaned the carb, soaked it, blew it out.

I'm wondering if I have to pull the heads off.

can I pull the plugs and look into it without pulling the heads.

It wants to run, cleaned out the tank, put new lines on it.

guess I have more work than I want to do to it.

any help?

GRP

ND1 · Post by **ND1** » Wed Dec 06, 2006 10:46 pm

I cant tell you whats wrong, but you can get a good look at the cylinders through the exhaust and intake ports, also get a mini flashlight with a flexible head and look down the spark plug hole, that will save you from buying gaskets.
Better yet, just do a compression test!
Then that should narrow down your problem searching.

afponiky · Post by **afponiky** » Wed Dec 06, 2006 10:52 pm

I went ahead and bought gaskets from DK (both soft and hard) so if I had to I will do that. I just didn't want to tear it down so far.

I guess after I look like you said I may have to look a little futher.

Thanks, I will look forward to any other postings to help me.

GRP

ND1 · Post by **ND1** » Wed Dec 06, 2006 10:57 pm

Is this a CCW or Kawasaki motor?
Any way it sounds like a carb problem.

harleysportster · Post by **harleysportster** » Wed Dec 06, 2006 10:59 pm

Gary,
what type of ignition, points or CDI. As stated, check the compression and let us know.

afponiky · Post by **afponiky** » Wed Dec 06, 2006 11:11 pm

The tag shows:

KEW 440 3414169 on the engine,

Eletomag box (CDI)

twin coil that are one of their own... there are two coils that each go to a spark plug. I tried switching them and it did not start up, put them back the other way and it started right up.

Single carb, Mikuni plunger type.

There only seems to be one jet screw on this carb, is this correct?

Gary

afponiky · Post by **afponiky** » Wed Dec 06, 2006 11:12 pm

What else can I check that will help you guys?

GRP

afponiky · Post by **afponiky** » Wed Dec 06, 2006 11:15 pm

Will a regular compression tester (like for a car) work on this? and is there a special way to do it?

I know there is a pressure test that I need to read up on if that is what your talking about. I don't know the procedure, but I will look it up. I believe it is to put about 7 pounds of air into the block.

well, I'm learning....

Gary

harleysportster · Post by **harleysportster** » Wed Dec 06, 2006 11:36 pm

Gary,
Check out the FAQ section on pressure testing. Also check out the section on dianosing the CDI sytstem.
http://z12.invisionfree.com/jdsleds/index.php?showtopic=431
http://z12.invisionfree.com/jdsleds/index.php?showtopic=491
The carb sounds to the right style. There are 2 screws, one in the center, left side for adjusting the idle and 1 near the rear, right side for adjusting the air mixture at idle.

afponiky · Post by **afponiky** » Wed Dec 06, 2006 11:47 pm

The one to the left side (drivers side if you were sitting in a car) does a lot with letting it run without throttle, (spelled right?) I seems that I only have one plug hitting, I don't just want to pull it out and try it without doing something to it because I've read that I can burn up the CDI box by doing that. The one screw on the right side doesn't seem to do much, it looks flush with the body of the carb and I didn't want to mess with it.

I do have ways of looking into this, but I don't know which ways. I'm wondering if I'm only hitting on one side, how would I be able to find this out without hurting something I have already (like the CDI box).

It sucks having a pull start to check some of this. you can't hold the wires to the electronics while doing that.

GRP

400brian · Post by **400brian** » Thu Dec 07, 2006 3:38 am

Gary

Mikuni slide carbs are an animal all to themselves. You need to understand how they work. It is not difficult, just different.

The two screws you mention: the one that screws into the side of the barrel affects how far the slide drops, it is the idle screw, works much like the idle stop screw on a butterfly carb.

The other screw is the idle air adjustment. It affects how much air bleeds into the idle circuit. It is the idle mixture adjuster, but it works backwards from what you arte used to on a butterfly carb. You are not adjusting fuel flow with this screw, you are adjusting airflow, therefore: screwing it in gives you a richer idle mixture, screwing it out leaner.

As for the plugs, you can get yourself an inline plug test light, but I think you are OK as long as the plugs are grounded to the engine ( laying on top of the shroud) .
Take one thing at a time, you could have a bad stator, or a bad CDI box, or mechanical problems, A compression test is not a cure all, but it will tell you if you have a hole in a piston or stuck rings or something like that.

afponiky · Post by **afponiky** » Fri Dec 29, 2006 2:25 am

I haven't given up yet, just haven't had the time to get to this one. The 600 been taking all of my time up (along with the kids, holidays, job, my wonderful wife, etc...) I finally got the seat on it, so I'm getting ready to look into the poor performance end of it.

Hopefully this weekend!

Thanks everyone, GRP