Mikuni 36mm CV carbs

[Gsx1100er]

The carbs I have bought  turn out to have come off a Swiss restricted Gsxr750.  Does any one know if the restriction was in the carbs or electronic via the CDU ?    The jets will be changed for B12 compatibility anyway so if it was carb restricted that should fix it ?

Cheers   Gaz

 

 

[Gsx1100er]

these are the carbs, can anyone id the carb model     ?                 

[inazumarob]

16 hours ago, Gsx1100er said:

The carbs I have bought  turn out to have come off a Swiss restricted Gsxr750.  Does any one know if the restriction was in the carbs or electronic via the CDU ?    The jets will be changed for B12 compatibility anyway so if it was carb restricted that should fix it ?

Cheers   Gaz

 

 

It would be worth checking the carb tops, it was popular in the 90's to restrict the opening height of the slides with a longer post moulded in the centre of the cap. This stops carb opening fully, you can shorten post if that is problem.

 

[Joseph]

Digging this up but it illustrates my question perfectly

On the last photo, at the back, the left hose is the petcock vaccuum, right hose the fuel intake.

What are the two hoses for on the front, stemming from carbs 2 and 3 ?

[TonyGee]

1 minute ago, Joseph said:

Digging this up but it illustrates my question perfectly

On the last photo, at the back, the left hose is the petcock vaccuum, right hose the fuel intake.

What are the two hoses for on the front, stemming from carbs 2 and 3 ?

vents 

[Joseph]

So i don't have to plug them or connect them to a closed circuit ?

[TonyGee]

Just now, Joseph said:

So i don't have to plug them or connect them to a closed circuit ?

it depends on the bike, some go to the airbox and some just vent to atmosphere, ( like bandits)

[Joseph]

Right, it's a BST34 for an 1127R engine with pods so if i can leave them out thats good

[clivegto]

On 12/3/2022 at 8:56 AM, Joseph said:

Right, it's a BST34 for an 1127R engine with pods so if i can leave them out thats good

Yea just vent them to the open air pointing backwards and down. 

[PeterC]

Your carbs  are bst36 cv,    measure the opening. 

[Gixer1460]

On 12/3/2022 at 8:56 AM, Joseph said:

Right, it's a BST34 for an 1127R engine with pods so if i can leave them out thats good

Don't leave the hoses off (if that is what you meant) - CV carbs can act funny if these pipes are removed as the area behind the engine is a low atmospheric pressure zone and as these vent the float valves that can affect fuel delivery.

11 hours ago, PeterC said:

Your carbs  are bst36 cv,    measure the opening. 

Thread is 3 years old and OP pictures were 36mm CV's - Joseph is referring to using 34mm CV's (why I don't know but he is in France) maybe just a general question?

[Joseph]

Yes just a general question about these pipes since 36 and 34s have them 

Yes i did mean off as in not connected to an airbox. If i run 2 pipes from the barbs to above the engine would that be ok ?

[Gixer1460]

12 minutes ago, Joseph said:

Yes just a general question about these pipes since 36 and 34s have them 

Yes i did mean off as in not connected to an airbox. If i run 2 pipes from the barbs to above the engine would that be ok ?

Yeah - that is std Blandit arrangement, but I think the tubes extend at least to the bottom of the cases (although I may be wrong on that!)

Edited December 9, 2022 by Gixer1460

[TonyGee]

the bandit pipes run from the carbs, over the top of the airbox and down to the bottom of the back side of the airbox.  

[Luigi]

On 12/8/2022 at 11:13 PM, PeterC said:

Your carbs  are bst36 cv,    measure the opening. 

I agree with PeterC.

@Gsxr1100er: From pics carbs are the same of BST 36 installed on my 1990 GSX750F. The Venturi passage (air filter side) on GSXR are round. These carbs have an almost elliptical shape instead. The only thing that i see different is the choke command: on my there' a cable attach, on these there's a knob.

More, the tube in brass you can see here is the passage to enrich the mixture at cold start.

:

If this carbs was coming from an usual GSXR750, the tube was on left, with a different form and function: for the GSXR is not cold enrichment, but Hi-RPM enrichment, in other words a Power Jet.

Maybe, but it's just a guess, this is the method used to restrict the power on Swiss models: installing a 36 mm carb instead a 38 mm...