Mikuni T38 flatslide questions

[Alpha]

hiya folks...

I have a new to me 1988 750 paso that I picked up over the winter. Pretty good shape (95xx miles on it), previous owner took off the weber and put on Mikuni T38 flatslides, on Malossi manifolds w/ K&N filters. Unknown non-stock dual aluminum exhaust cans (look nice!).

I am just getting into the bike and about to do a baseline belt change and valve adjust...

But, the bike is running a bit rich and the idle will hang up at 3k RPM from time to time - not good! It does not seem to be cable routing, I can hear the throttle slides snap shut. Seems like the carb angle is pretty severe on the horizontal cylinder - am I sloshing fuel into that cylinder and that's my high idle issue? The fuel pump and bypass are in place can I be overwhelming the floats? (saw a little fuel in overflow lines - so either this or the floats are too high).

So just would like some feedback from you listers on what a good Mikuni T38 setup should be for this bike.

1. What angle is allowable on the Mikunis? Malossi manifolds OK? Is that low angle horizontal cylinder manifold out there still?
2. Suggested jetting (ballpark)? - pulling them apart tonight to see whats in there.
3. Fuel pump/bypass or just gravity?

Thanks people!

C

[higgy]

Don't have it handy but there is a manifold made to sort it out, do a search on Paso manifolds

[giocast]

you have a 'bun and the ha'penny' situation with the horizontal inlet Alpha - it's the same for the Keihin FCR flatslide, even if you use the 'downdraught' version just for the horizontal cylinder as it isn't a truly downdraught design. As many Keihin FCR users have found, it's a case of either putting up with the occasional flatspot/stalling after braking hard or adapt for the standard, longer (and cranked) inlet ports used on 900 Ducati's so that the float chamber gets a decent chance at working how it's supposed to.

[higgy]

http://www.youtube.com/watch?v=7FDx-lpW27k

[Alpha]

OK thanks guys...

Will check out the youtube video when I get home - I.T. has us blocked out of anything fun here at work...

any comments on deleting the fuel pump from the mix - don't see why the previous guy left it in the loop, gravity should be fine.

I saw the flatter, more angled manifold someone posted:

http://www.autotrimdesign.net/detail.js ... gory=72142

have to call today to see if its still available - anyone using this thing?

How about some ballpark jetting specs too - anyone? anyone? Bueller?

Chris

[paso750]

the video belongs to the company in your link.
If the carbs are about the same height as the fuel petcock or even higher you will need a fuel pump otherwise you will run out of gas when there`s still some in the tank.

G.

[paso750]

jetting of the original 750SS Mikuni BDST38 carb

main jet: 140
main air jet: 70
needle jet: Y-6
Jet needle: 5C19 - 3rd notch from top
Pilot jet: 37,5
Pilot air jet: 60/1.4

[88WhitePaso750]

I have TM38s on my 750 as well. I was getting fuel leaking from carbs after shutdown. I replaced needle valves on both carbs and replumbed the fuel system include a 12V fuel solendoid as close to the carbs as possible to present and head pressure from forcing fuel through carbs and onto the floor after shutdown. So far so good.