Diagnosis help

[pete]

You know... looking at the inside, they look eerily like my 450 float bowls. The only obvious difference I see is mine don't have the overflow on the float bowl... I wonder if it would be worth trying an 80 - 82 450 float bowl if you can't locate a 400 one?

Alternatively, get a set of the 450 or early 500 carbs as I believe they should be a straight swap...

[droyce]

You know... looking at the inside, they look eerily like my 450 float bowls. The only obvious difference I see is mine don't have the overflow on the float bowl... I wonder if it would be worth trying an 80 - 82 450 float bowl if you can't locate a 400 one?

Alternatively, get a set of the 450 or early 500 carbs as I believe they should be a straight swap...

Pete, the 80-82 GS450 bowl I don't think have the trench I need.

http://www.ebay.com/itm/SUZUKI-GS450-GS-450-MIKUNI-CARB-CARBURETOR-CARBURATOR-FLOAT-BOWL-BOWLS-80-82-/300415533718?pt=Motorcycles_Parts_Accessories&hash=item45f2294296&vxp=mtr

Getting a whole set of carbs would be another, more expensive, option. Is there a performance advantage to getting the 450 or 500 carbs? Would the intake spacing be the same? Can someone measure?

[Mekanix]

Measure from outside of your carbs in the front and ill measure a set of my 1979 carbs.

My 79's are 149.5mm and so are the 80 and 81

[pete]

Pete, the 80-82 GS450 bowl I don't think have the trench I need.

http://www.ebay.com/itm/SUZUKI-GS450-GS-450-MIKUNI-CARB-CARBURETOR-CARBURATOR-FLOAT-BOWL-BOWLS-80-82-/300415533718?pt=Motorcycles_Parts_Accessories&hash=item45f2294296&vxp=mtr

Getting a whole set of carbs would be another, more expensive, option. Is there a performance advantage to getting the 450 or 500 carbs? Would the intake spacing be the same? Can someone measure?

No worries... unfortunately I haven't seen the photos of your float bowls, for some reason they never showed up for me...

From the 400's onwards the carb spacing appears to be the same... I've seen people put 80 - 82 carbs on earlier 400's and a 425 I'm pretty sure, and I've seen 500 carbs go on 450's.

[barnbiketom]

The carb's internals are different but they sound like they are a bolt-on and would work. BUT

I wish someone had just a bowl for you!!

did you post in the wanted forum here?? someone will have one!

[droyce]

The carb's internals are different but they sound like they are a bolt-on and would work. BUT

I wish someone had just a bowl for you!!

did you post in the wanted forum here?? someone will have one!

I did make a post in Wanted forum. Is there a possible performance upgrade with a later year carb setup? Because I'm bored over to 448cc, I'm wondering if the GS450 carbs may be a better match anyway. Any advice or knowledge?

I mean cost wise I'd like to just be able to pickup the proper bowl from someone, but running different carbs has me intrigued.

Also, which set would be more reliable and readily available for replacement parts if I have to go that route?

[pete]

You'll probably find the biggest difference will be the jet sizes... I imagine the stock ones are probably a little larger for the 450's and 500's, and I'm going to assume Mikuni made improvements but who knows?

One thing I like about my 82 carbs is that I can change pilot and mains without removing the carbs, I can just drop the float bowls.

I haven't tried it yet, but I think I could do the needle adjustments just by taking the tank off too.

[droyce]

Found a nearby salvage yard that said they might have one. I'm suppose to hear back today, fingers crossed.

[pete]

That would be very handy... let us know!

[Mekanix]

I can swap my gs500 and 400 carbs onto each head.

If the 500's are easier to come by at a good price, it might be good to look at those. The jets for the 89 are 120 main and 35 pilot.

[droyce]

Well found a set of carbs for $37. Should be here in the next week or so, then we'll fire her up!

[Mekanix]

What did you get ?

[droyce]

Another set of gs400 carbs. I'll just swap on the bowl and have an extra set as backup.

[barnbiketom]

great!! hope that's all you need!!!

[droyce]

Well I think the set I got are actually from a gs450. Because there were no trenchs in the float bowls, but after some careful examination I realized you can just punch a hole in the float bowl gasket where the pilot jet sits, and this allows the fuel to flow through. Easy fix, but at least now I have matching bowls, an extra set of carbs to polish up, and some different jets to tune with.