TOPIC:

As you may know by now, I am still working on tuning my bike on the single VM34 carb.

yesterday I took my bike for it's first "long" ride (about 40 miles round trip). At about 30 miles I finally fouled a plug. Luckily I brought a backup.

The plug that fouled was my right plug. When I got home, I checked my left. It was black, but didn't look like it would foul anytime soon.

In looking at my 2-1 manifold more, I feel like the guy who made it may not have allowed enough straight pipe before the 90 degree bend, causing the fuel to flow into the right cylinder at a higher rate than the left cylinder.

I know this picture sucks, but will you guys verify my logic here and let me know if this makes sense?

1) tubing is to large in diameter
2) radius on the bends are to big

Nebr_Rex wrote: 1) tubing is to large in diameter
2) radius on the bends are to big

Damn. I got ripped off. Guess a new manifold is still cheaper than 2 new carbs. Plus I've pretty much got this carb dialed in except for the inconsistencies between the right and the left cylinder.

I know this is an old topic but I have a couple of questions. Treitz....I've seen you on here and DTT a lot. Did you end up hashing out the single carb setup? If you are still sticking with the single carb setup, what manifold have you settled on, 11th hour? Does anyone know of a member (here or any other forum) that has claimed success with a single carb setup? I'm having trouble pinpointing someone.

I run a completely functional single carb set up on my Goldwing 4 into 1 carb cant remember all
of the particulars but it served me many thousand miles while I was putting my KZ together and is
still functional today

the way it was explained to me is that gas atomizes into a vapor that fills the chamber and is
loaded when the intake valve opens so while size of carb and runners may play a role a single
42mm is standard equipment with a 1340cc v twin it should flow and atomize enough vapor to handle a
1200cc 4 cyl. using that logic a single 24, 26 or 28 is plenty for fuel volume even a 22 would easily supply the fuel

the length and size of runner aids in atomization. I have been told can also manipulate toprque curve but I am not a guru mine uses rubber connectors into pvc connected to a aftermarket Harley intake and is plenty serviceable The aluminum atomizes so well it will frost up.

The secret is the jetting expect to spend the day with different combination until you find the formula
I'm not much help other than to tell you the first intake design worked out with enough jetting combinations including drill the jet to desired size

good throttle all the way through






I was ready to scrap the project at after the first ride but kept playing with it until by the end of the day
I had one of the most dependable set it and forget it bikes I have owned

I cant take credit for the tuning that was all done by my brother who without, the bike would have sat
another year and probably would still be sitting.
don't over think it build a reasonable intake and jet to it

Thanks for the response ramtough...
I'm having so many problems that getting this thing to idle consistently would be a great step in a positive direction. I think I need some more time to get there but once I do I'm hoping it will be fun to ride my new found purchase/hobby!

Just posting a couple of single carb topics. I don't know that much about this stuff, but you might want to consider having a short extender between the carburetor & pod filter. I guess something about the length of the airbox ducts?... doing so may help the air flow? The pod filter may already provide some offset from the carb.

My Custom Bobber 440
2004 kfx400 atv carburetor & copper tubing manifold.

KZ440 Single Carb Conversion
New Mikuni VM34 carb & stainless steel manifold (?)