Don't use Kem dip ?????

[KA1J]

I have a full set of the JIS screwdrivers and they tend not to strip the heads of the screws, no question they are the right tool for a Yamaha job. Not good for Harley or BMW.

I've replaced the throttle shaft screws on two sets of carbs so far and I used a deburring tool on a Dremel to grind the ends off the screws. They are installed at the factory and then the threaded ends sticking out are whacked by a hammer, I don't know the exact process. The whacking bulges & flattens out the end of the screw so it won't come off even if it loosens.

I made a thin 1" wide barrier of epoxy putty that I pressed-fit inside the shaft and had oiled the metal first so the epoxy wouldn't stick. I pulled it out when almost completely hard & cut the ends to shape so it would fit inside the shaft as a shield so I could get at the throttle shaft screws easily and if the deburring tool jumped while I was grinding, it would hit that epoxy shield and not the metal in the shaft.

It was a good idea, the deburring bit jumped a couple of times but with zero damage. The epoxy barrier was easily moved to the other carbs.

I never ruined any of the heads of the screws and did buy new screws but I don't think I'll buy new screws the next time because yes, the new screws are new but the thread goes in the same distance either way & I used blue thread locker when re-assembling them. Besides, I'm not convinced the replacement screws are JIS but the originals are.

[SFerinTEXAS]

Would'nt the screw driver in the oem tool kit be good for this?

[KA1J]

Would'nt the screw driver in the oem tool kit be good for this?

Too big. I "think" that's a #3 size & these throttle shaft screws are either #1 or #2 & I think #2. I believe the screws in the slides are #1.

[Tat2demon]

When I cleaned my carbs I pulled the screws and replaced them with stainless allen heads.

Only had one screw give me a headache. I ended up using an extractor on it. The rest came right out.

[mharrington]

Its unfortunate that shaft seals are very inexpensive BUT difficult to install and cause much grief when they are bad.

[jetmechmarty]

Its unfortunate that shaft seals are very inexpensive BUT difficult to install and cause much grief when they are bad.

These bikes are over 30 years old. The good news is that OEM shaft seals are available. I don't care to think about how old I'll be when they need to be replaced again.

[donebysunday]

Over on GSR, we swear by that stuff, and I've cleaned a good 7-8 carb banks not needing to them twice, is there something specific to the Yummy carbs that the butterfly seals are more prone to damage than the cousin BS34's on a Suzuki? What is the best substitute cleaner? I've used the good Pine Sol with no real luck, don't want to use vinegar, and don't have access to an ultra sonic cleaner. Trying to to do this myself and at a reasonable price.
I know it another dead horse getting beat again, but would like to hear from some success stories and specific products used. I want to do them right the first time, not the second or third.
Thanks

Depends on how long they are left in the chem dip. On my 650 carbs over night seems to do it but then I switched to the Yamaha cleaner and left for a week with no problems. YMMV

[mmatches1]

I recently dipped my carbs in a vasol based parts cleaner and forgot to remove the shaft seals. I decided to replace them and when I extracted the seals noticed that they were hard and had lost flexibility. Not sure if this was from age or from the parts cleaner. I purchased replacement seals from the Canadian MIkes XS (XS Direct). These are the same seals used on XS650's. ALl my butterfly screws but one came out and I had to drill it out. Since then I purchased a set of Japanese screwdrivers.