Results of putting airbox back on

Some might be surprised just how much you can tape up a set of pods without affecting the engine, even at the drag strip.

There are a lot of variables that play into the mix but all things considered, I'm absolutely convinced that for best all around performance, a still air chamber provides the carburetors with the environment they like best.

If you can make it's volume adequate to feed the size of the motor's demand at it's peak HP RPM, you'll find the bike just flat out behaves better everywhere.

If someone sends me a complete KZ1000 airbox they don't need for a while, when I get some free time, I'll do some flow tests on it. In all these years, I've never tested a stock airbox. I'd kind of like to know myself just how big of a motor it could feed

"KZ1000 airbox they don't need for a while,"....

Now you freaking tell me.... :laugh:

Matter of fact I do.... The 1000 came with an air box but the nipples are broken off... easy remedy to repair I believe...

That work for ya?

OMR,

The carbs are 1980ish VM28s. Head was rebuilt and ported by Pit Stop. New guides, seals, APE HD valve springs, and 3 angle valve job. Pods are used K&N's that I bought off of Ebay. I bought them because they are marked as Vance and Hines where it normally says K&N. Look to be in good shape. I'm running the stock cams. I was going to change the cams, but I'm pretty happy with the way it runs now. Someday I will want more power. The head is already clearanced for larger cams.

Just of of curiosity, had you changed your needle size for the pods?

Based on "I couldn't get rid of the surging while cruising down the highway".... first thought would be running lean... I'm sure you had tried various needle clip positions with less then ideal results...

Example, if at max clip position and surge still present, then needle change would be the first thing to do....

Doesn't really matter now where air box back on and you're back to no surge... Excellent, objective met... right on.

OMR,

I tried shimming the stock, nonadjustable needles. That didn't work. I then put in the adjustable needles out of my original vm26 carbs. I set them full rich. That helped but didn't cure it. I could almost cure the surging by tweaking the airscrews. But, that made the idle so rich that it would foul the plugs. Maybe different needles would have fixed it. Honestly I flat out got tired of pulling carbs! Like you said it really doesn't matter since its running good now.

Had you started with a brand new rack of CRS29 carbs, you would have had much better results and most likely never even have given the airbox a second glance.

larrycavan wrote:

If you can make it's volume adequate to feed the size of the motor's demand at it's peak HP RPM, you'll find the bike just flat out behaves better everywhere.

If someone sends me a complete KZ1000 airbox they don't need for a while, when I get some free time, I'll do some flow tests on it. In all these years, I've never tested a stock airbox. I'd kind of like to know myself just how big of a motor it could feed

+1

and I'd love to see that data!

+2 ditto:)

Already spoke to Larry... I need to order some new Air box hoses (Z1) from Jeff and repair the broken barb fittings then off to him for CFM measurements and such...

Will be a week or two before I get it out to him....

OMR

larrycavan wrote:

Had you started with a brand new rack of CRS29 carbs, you would have had much better results and most likely never even have given the airbox a second glance.

I'm sure that you are right. But, I got these VM28 carbs for a great price. I didn't have the money for new carbs after rebuilding the motor. Plus I learned a lot about how carbs worked over the last year!

When I get bored with my newfound power I will put cams and new carbs on it. That should give a nice boost to what is already a very stout motor.

fordtruck wrote:

When I get bored with my newfound power I will put cams and new carbs on it. That should give a nice boost to what is already a very stout motor.

fordtruck wrote:

larrycavan wrote:

Had you started with a brand new rack of CRS29 carbs, you would have had much better results and most likely never even have given the airbox a second glance.

I'm sure that you are right. But, I got these VM28 carbs for a great price. I didn't have the money for new carbs after rebuilding the motor. Plus I learned a lot about how carbs worked over the last year!

When I get bored with my newfound power I will put cams and new carbs on it. That should give a nice boost to what is already a very stout motor.

It's hard when you're working with limited funds and old parts. You've done a good job with it. It's like the cake is baked and the icing has yet to go on.... When it does...you'll enjoy every bite