Enlarge Pilot Bypass Holes

Hi guys!
Has anyone of you ever enlarged by drilling the pilot bypass holes? AKA transition ports. I came across a website that does recommend it along with other mods and a jet kit. It is for a yamaha, but I think the concept can be applyed to any carb.

www.cartestsoftware.com/fz1/jetkitinstallation.html

Regards,

Got a extra set of carbs incase you mung them up?
Steve

Yes... did you ever hear about this?

I'd rather let someone else try it first I'm not clear what "problem" this is designed to cure or exactly how it is beneficial, it brings to mind the expression "if it ain't broke, don't fix it" as Swest says if it doesn't work it's a lot of expense and hassle to undo it, I'd certainly want some model specific information and proven results from users before attempting anything like that.

What are you trying to fix? The KZ750-4 was a damn fast bike when new, and no one had to screw around drilling big holes in the carbs to make it run well. I wouldn't do that to my worst enemy's bike. If your bike isn't fast you need to consider finding the problem rather than creating a new problem trying to modify the carbs. Ed

In that particular bike, it is suppose to address and solve the "off idle" hesitations.

The KZ750-4 didn't begin life with off idle hesitations; they had plenty of ooomph from idle to redline. If yours has that problem it either needs a tune-up, or perhaps it doesn't have the proper air box and filter installed. Ed

swest wrote: Got a extra set of carbs incase you mung them up?
Steve

That's the first thing I thought of...... the gunsmith's code is always drill or cut on the cheapest part first, the most expensive is only as a last resort.

Sounds like a pod tuning thing.

Once you do it there is no turning back...... I sure wouldn't.

Ed, I did not say my bike has that symptom. I was just asking if any of you had ever even listen of this mod. For me it was my first time. And yes my bike has stock airbox and filter. Still feels like a bigger pilot would suit her well.

First time I have heard of this mod

About 10 years ago I bent the tip of a pin 90 degrees and poked out those holes to get them clean and it cured a hesitation/stutter at 2,500 RPM. Drilling at an angle as in the photos seems extreme but if you have a spare set and dont mind the risk then it could be interesting.

I have a slight popping in the exhaust on deceleration and was thinking I might be a tad lean but am now thinking exhaust leak. When the snow melts in March I think I'll put in new thicker exhaust gaskets.

This is one of Ivan's jet kits. He knows what he's doing. I had an Ivan's jet kit on my ZRX and that bike ripped. Now I have Ivan's kit on my H2 and it runs much better than with the stock needles.

Neither of my kits required drilling out passages like the FZ1 kit. I'm just saying Ivan knows his stuff.

Whether drilling the passages will help a KZ750, who knows unless you have the time and maybe a dyno to fine tune your bike.