83 KZ750 shaft keihin pilots?

I need to go up to 45s or 48s on my pilot jets, but apparently they don't make them, or I just ahvent found them. The carbs are the keihin CV34. I can buy a new set of stock 35s for a decent price. Is it hard to drill them out? What size bit would I need? I know it isn't the right way to change my pilot sizes but it's looking like my only option right now. Anyone have any experience with going up in pilot sizes with these carbs that can lend me some advice? The stock jet part number from Kawi is 92064-1001.

Hi there
I believe I have pretty much the same Keihin CV34 carbs on my 1980 750E1 (4 cyclinder) with the same# 35 pilot jets.
I dont believe the pilot jets are available anywhere and I dont think Dynojet have them in their kits although you could try searching their website.
Having said that, I have a 4->1 exhaust and have successfully run K&N pods and now a stock airbox for the stock look and while I have played quite a bit with jetting I have never needed larger pilots. Now that I think about it I would say that to hear of someone looking for larger pilots for the 750/4 is rare. I just wonder if you what symptoms you are experiencing that make you believe you need larger pilots. Of course I could be way off base here and you have a heavily modified engine so apologies advance if thats the case.

The pilot system in the CV34s has a number of internal passages some of which are very narrow and blockages can be hard to find and can cause pilot problems. Soaking with carb cleaner is never enough and thorough cleaning usually requires a nylon bristle or a 1st guitar string or I have even used 50lb strain nylon fishing line and all followed by blowing everything with compressed air.

When I bought my bike bike back in 03 I lost count of the number of times I cleaned the carbs trying to fix a low speed (pilot) issue and then I discovered the "Bypass outlet" holes. See attached picture
These 3 holes in a triangular arrangement are on the engine side of the carbs and you need to have the throttle butterflies wide ope before you can see them. They are tiny and crud can block them. I used a long pin with the tip bent at right angles to clean them out. Another are to investigate would be the pilot screws and the pilot outlet.
Hope this helps

I am having problems with the low end. It stumbles and hesitates at anything below 3000-2700 rpms. It's a ton worse when cold. My engine is stock, but the exhaust is straight pipes basically. I hollowed out the stock megaphones. I've had 3 bike shops all look at it and they all said I need bigger pilots. The kz lover at one of the shops said I would also need bigger mains too. The carbs are completely cleaned. I will triple check those passages when I pull them again in the next few days. I am assuming that the 4 into 1 exhaust would not affect the low end as bad as the 2 into 1 stock with no baffles at all. My 2 options I can think of right now, are to drill the pilots bigger- a new stock 35 set is only $40 if i manage to screw it up. Or find some mikuni bs34 carbs and swap out the carbs.

Good Fortune!

rboutin2 wrote: I am having problems with the low end. It stumbles and hesitates at anything below 3000-2700 rpms. It's a ton worse when cold...........................

Thats EXACTLY what I was experiencing (bad stumbles under 3000 rpm) when I got the bike first with 4->1 and individual pods. I cleaned and cleaned and gave up and wasted $300 at a bike shop who blamed the pods and finally with the riding season almost over I did a really thorough and painstaking carb cleaning and found those holes and poked them clean.

If everything is clean then these carbs work well and are very forgiving when it comes to modifications.

Patton has just posted a great diagram above. Squirt in carb ckeaner where he has highlighted and make sure to wear safety glases. That stuff will come right out where least expected and is extremely painful when it hits an eyeball
Good luck

PS
the manual mbsween.bike-night.com/kz750l3/manual.html has a good section on carbs at about page 310

Regarding the exhaust I found that upping the secondary main jet from stock 125 to 130 worked well with the 4 ->1
Your bike being an 83 shaftie may have different stock jetting but the above should give you some ideas of what you might need. These jets are available from Z1 Enterprises for about $2 each

Upping Primary main jet from stock 62 to 65 also works wonders!
130 - 65 - 35 is Wired George recommended setup for 4-1 and K&N inside air box.

JR wrote:

rboutin2 wrote: I am having problems with the low end. It stumbles and hesitates at anything below 3000-2700 rpms. It's a ton worse when cold...........................

Thats EXACTLY what I was experiencing (bad stumbles under 3000 rpm) when I got the bike first with 4->1 and individual pods. I cleaned and cleaned and gave up and wasted $300 at a bike shop who blamed the pods and finally with the riding season almost over I did a really thorough and painstaking carb cleaning and found those holes and poked them clean.

If everything is clean then these carbs work well and are very forgiving when it comes to modifications.

Patton has just posted a great diagram above. Squirt in carb ckeaner where he has highlighted and make sure to wear safety glases. That stuff will come right out where least expected and is extremely painful when it hits an eyeball
Good luck

PS
the manual mbsween.bike-night.com/kz750l3/manual.html has a good section on carbs at about page 310

I dont have a secondary or primary main jet. just main jet and pilot jet. pilot is a 35 and the main is a 100. needle is n10c. I will check those passages to be sure though and let yall know what if any change.

Good Fortune!

Good Fortune!

I posted some pics of my manual stating the jets and also a picture of the carbs. It is under the F1 column. I'm not trying to be rude or anything but could you point out the main primary and main secondary? I only see the main and the pilot on these carbs. Also, I am getting a nice spray of fluid from those 3 holes by the throttle plates so they are completely free. So should I try going up in main jets first then see how it runs? How much should I go up?

Hi again

In my photo below from one of my jetting experiments 8 years ago the one marked 135 is the secondary main. The jet marked 62 is the primary main. The pilot jet is under the plastic plug on the right. Its not a great pic and is the other way round from yours. The numbers are stamped on the jets and I need a magnifying glass to see them .

In your picture the primary main and the plastic plug are removed. If they are truly missing then that would be a problem but if they have just been removed for the photograph and carb cleaner is coming out all the correct holes then perhaps upping your 100 to 105 or 110 might be worth a shot. Maybe I'll have a clearer head in the morning.