Tool for adjusting pilot fuel screw?

[93Bandit]

I'm working on getting my '77 GS750 running and rebuilt the carbs yesterday. I adjusted the pilot fuel screws to 1 full turn out as suggested in the rebuild tutorial, but once the carbs are on the bike carb 2 & 3 pilot fuel screws are a real pain to get too. I cut off the end of a screwdriver short enough to fit under there, but I can barely get my hand in there to turn it. Is there a special tool out there to adjust these screws while on the bike? Or any other ideas? Or, do I have to pull the carbs every time I need to make an adjustment? I sure hope not... Any help is appreciated, thanks!

I searched the forum but didn't come across anything concerning my question specifically.

 

[timebombprod]

I'm working on getting my '77 GS750 running and rebuilt the carbs yesterday. I adjusted the pilot fuel screws to 1 full turn out as suggested in the rebuild tutorial, but once the carbs are on the bike carb 2 & 3 pilot fuel screws are a real pain to get too. I cut off the end of a screwdriver short enough to fit under there, but I can barely get my hand in there to turn it. Is there a special tool out there to adjust these screws while on the bike? Or any other ideas? Or, do I have to pull the carbs every time I need to make an adjustment? I sure hope not... Any help is appreciated, thanks!

I searched the forum but didn't come across anything concerning my question specifically.

i just take a flathead bit from a interchangeable screwdriver kit and use that to tighten or loosen it, mixture screws should have no problem moving about when doing it like this, if anything 2&3 might need to have the rear tank bolts taken off so you can tilt the tank up and get to them easier.

 

[Nessism]

i just take a flathead bit from a interchangeable screwdriver kit and use that to tighten or loosen it, mixture screws should have no problem moving about when doing it like this, if anything 2&3 might need to have the rear tank bolts taken off so you can tilt the tank up and get to them easier.

Bandit is talking about the pilot fuel screws on VM carbs, which are by the float bowls.

I used a stubby screwdriver, which I further chopped down. 1 turn out on those screws is typically too rich. Try between 3/4 - 7/8 of one turn for a start.

 

[93Bandit]

Bandit is talking about the pilot fuel screws on VM carbs, which are by the float bowls.

I used a stubby screwdriver, which I further chopped down. 1 turn out on those screws is typically too rich. Try between 3/4 - 7/8 of one turn for a start.

sounds like we both had the same idea for approach. I guess I'll just try to limber up my hand a bit and give it another attempt. I'll set them to 3/4.

Thanks!

 

[oldGSfan]

I tape a small screwdriver bit in a 1/4" socket. You'll get good feel for it, lightly searching around for the right angle. I also put some marks on the tape as reference so I know how much I'm turning.

 

[steve murdoch]

Ask Santa for a 90 degree from Motion Pro.
There are cheaper versions out there.
https://www.z1enterprises.com/carb-pilot-screw-adjusting-tool.html

 

[93Bandit]

I tape a small screwdriver bit in a 1/4" socket. You'll get good feel for it, lightly searching around for the right angle. I also put some marks on the tape as reference so I know how much I'm turning.

That's a good idea, I'll try that.

 

[93Bandit]

Ask Santa for a 90 degree from Motion Pro.
There are cheaper versions out there.
https://www.z1enterprises.com/carb-pilot-screw-adjusting-tool.html

Man that's tempting... But how many times will I use it??? Never hurts to have another tool I suppose...

 

[alke46]

Only time I've ever touched mine was after soaking in carb dip and reassembly. Set them to either 5/8 or 3/4 of a turn out and forget about them.
This has always worked for me.

 

[Guest]

Only time I've ever touched mine was after soaking in carb dip and reassembly. Set them to either 5/8 or 3/4 of a turn out and forget about them.
This has always worked for me.

same. My bike is pretty much all stock so I use the the little index marks next to the pilot fuel screw on my post January 1st 1978 emissions style carbs and then tune for the highest idle on the air screws.

 

[steve murdoch]

Man that's tempting... But how many times will I use it??? Never hurts to have another tool I suppose...

"How many times will i ever use it?" You are looking at it all wrong.
Get the tool...get more bikes!

 

[93Bandit]

"How many times will i ever use it?" You are looking at it all wrong.
Get the tool...get more bikes!

I like how you think. I have 4 bikes (one is basically only parts) and I'd like more, but wifey said I need to fix the ones I have before I can get more. Sometimes it annoys me, but most times I understand that she has what I lack; self control... She's my voice of reason.

 

[pdqford]

Happy wife.
Happy life.

 

[bwringer]

Ask Santa for a 90 degree from Motion Pro.
There are cheaper versions out there.
https://www.z1enterprises.com/carb-pilot-screw-adjusting-tool.html

I have one of these, and it's a beautiful tool but thus far it has been useless. It just doesn't fit where it needs to fit on any of the bikes I've owned or the many that have passed through my garage. And even in the rare situations when it actually fits, there's zero feel, so it's really hard to tell whether the bit is engaged with the screw. Yes, I tried it without the detent ball.

Man, it sure is a pretty tool. But in my experience, it just doesn't work.

From the top, I use a really long, slim driver with the tank off. From the bottom, I have a selection of teensy weensy drivers in different lengths, handles, etc.

 

[Forden]

A little dental mirror is helpful to see the screw, easy to find the slot and helps me be precise on how much rotation.

 

[Chuck78]

Bandit is talking about the pilot fuel screws on VM carbs, which are by the float bowls.

I used a stubby screwdriver, which I further chopped down. 1 turn out on those screws is typically too rich. Try between 3/4 - 7/8 of one turn for a start.

Same here, the tiny Harbor Freight or Tektron mini stubby screwdrivers with the handle shaved down a bit.

I also have a Motion Pro cable operated 90? screwdriver for Honda carbs slightly modified to fit GS/KZ VM carbs

 

[Guest]

I'm working on getting my '77 GS750 running and rebuilt the carbs yesterday. I adjusted the pilot fuel screws to 1 full turn out as suggested in the rebuild tutorial, but once the carbs are on the bike carb 2 & 3 pilot fuel screws are a real pain to get too. I cut off the end of a screwdriver short enough to fit under there, but I can barely get my hand in there to turn it. Is there a special tool out there to adjust these screws while on the bike? Or any other ideas? Or, do I have to pull the carbs every time I need to make an adjustment? I sure hope not... Any help is appreciated, thanks!
L
I searched the forum but didn't come across anything concerning my question specifically.

I use an adaptor that joins a quarter inch drive with screw bits. It is a blue aluminum disk with knurled sides. Easy to manipulate with your fingers and you can quickly interchange different screw bits. I insert a long drill flat bit and twist away. Can send photo if you would like to see

 

[Guest]

Kobalt is the manufacturer

 

[Chuck78]

Kobalt is the manufacturer
View attachment 63810

I also have that setup for the VM fuel screws, along with a modified Motion Pro right angle cable drive screwdriver, and modified Harbor Freight micro sized thumb screwdrivers.

The Motion Pro right angle screwdriver works significantly better on a hot engine as to not burn yourself, but it is sometimes difficult to find the slot in the screw.

 

[Chuck78]

Certain Kawasaki KZ1000 or maybe z1r models around 1977 - 1979 used a VM 26 or actually VM28(?) with the fuel screw on the bottom and had a knurled extension that hung down below so that you could just grab them and turn them with your fingers, from what I'm recalling. I meant to track down some of those.