1978 Slide Assembly Differences?

[zyphermonkey]

I have two 1978 GS750's. One is a basket case I bought for $250 that I only plan on using for a parts bike. The other is one that I bought running but needed a little work and has been my project bike so far this year.

With that said I decided to clean the carbs on the good bike and ended up sheering off the end of the pilot fuel screw in the carb and even following bikecliff's guide to get it out all I ended up doing was flaring the end of the brass tip so now it won't budge anywhere.

No worries I thought I'll just clean up one of the carbs off the other bike and everything will be okay. While cleaning up the carb from the parts bike I found that the slide assemblies were different. (See pictures below)

The question I have is why are these slide assemblies different from the same year bike and would it be possible to mix and match?

Good bike on left ---- Parts bike on right



















-Merrel-

[tkent02]

Use the old needle and slide so the fuel metering is kept the same. The early bikes didn't have the spring loaded needle, it's purpose is to keep the needle cocked to one side, which keeps the needle from rattling around in the needle jet and wearing itself out.
Either type is fine, but use them all the same across all four carbs.

[zyphermonkey]

Okay thanks.

What is the stock notch to use on the needle type with the spring?

[tkent02]

Look on Cliff's site, also make sure it is the correct part number on the needle.

I see cliff hasn't been here yet, he's really scary.
Look here, everything you could possible need for any GS...

http://members.dslextreme.com/users/bikecliff/

[Detroit Diesel Man]

Heres a direct link to the Carb specs via cliffs site..

http://members.dslextreme.com/users/bikecliff/images/carbspec_float_height.html#A01

[zyphermonkey]

Got the old carbs all apart and I'm dipping the bodies.

After all that I started taking apart all the other slide assemblies and one of needles is in pretty bad shape.

Does anyone know the part number on the longer version needle?

5F21 is what the sheet says and I know that can't be right because that's the part number for the short needles I have.

[BassCliff]

Hi,

Isn't the needle on the right a Dynojet needle?




Thank you for your indulgence,

BassCliff

[zyphermonkey]

BassCliff,

I don't know if the one on the right is a dynojet needle or not. There is zero identification on it.

Will I be okay using the 5F21 Needle in the other carbs slide assembly?