It RUNS! But it's lean. Pics.

[atchbo]

So, at long last, I took my GS400 for a spin today. I may have busted off a case/cover bolt putting the left side back on, but she idles and runs pretty decently. I replaced the clutch pushrod oil seal for the 4th time, and I think it still leaks (or something under that cover leaks), but I'm done fixing that stuff. She can leak.

The bike ran pretty well through the range of RPM. I didn't blast it... just around the neighbourhood, but it pulled strong up to 6000 and seemed like it would have kept going. But check out the lean plugs. First, the bike.

[atchbo]

Right plug.

[atchbo]

Left plug.

[chef1366]

If those are brand new plugs you are looking good.
Count how many threads up the spark plug have color to guage heat range. If you're below 2.5 ride that puppy.
Have fun

[Steve]

Here ya go, all in one post:

The bike:


The right plug:


The left plug:

[Nessism]

Did you rejet the carbs to run with pods? It's pretty much manditory if you didn't know.

[chef1366]

I didn't see the pods. The need to rejet is manditory or your engine will be short lived.
You'll need to go up on the main jet and shim your needles OR get a Dynojet kit.
If you are pulling strong to redline with no bogging you or somebody must have rejetted.

[Dreef1999]

Is the GS400 the only pre '80 GS that has CV carbs?

[Nessism]

Is the GS400 the only pre '80 GS that has CV carbs?

Does the 1979 GS425 count?

[atchbo]

It's two sizes up on the main jet, one size up on the pilot jet and needle raised one clip position (clip one position down from centre).

I have some new fishtail exhausts coming, which will get baffles, but I may have more to do on the jets. I was surprised the plugs were so clean. On the stand it was fouling plugs a bit. These plugs are B7es, so hotter plugs. I may put the B8es plugs back in and see if they clean up.

Thanks for the pointers.