Still some bugs at 3/4 trottle

[gsx1100norway]

Hello

My GS1100E -82 still struggling from 3/4 trottle and up.
Feels like it starves for fuel, but I have tried main jets from 130 to 160 with the same results.
It idle OK and further up to this 3/4 trottle problems appear.

Since I have Webcams G2 dialed to 110-110 and 4-1 exhaust AND pods + Dyna-S , my toughts are that it could be something wrong with this cam timing, but I dont think this
should appear at the higher RPM`s ? Anyone ?

Thankfull for any advice for next step...

Knut

 

[rudeman]

How's your fuel level in your float bowls?

 

[Guest]

One tooth off on the cam timing and you would not be getting any power at all and you would know something was drastically wrong. I had A similar situation with my bike when I was setting it up for 4-1 pipes and pods. It was too rich and would start stuttering and fowling plugs trying to break through from 3/4 throttle to red line (ran fine up to that point). It finally showed itself one extremely humid hot day and fouled a plug to the point of running on three cylinders. I leaned the main needle one notch and it took care of the problem. I have a different series of carburetor from yours (VM) but that doesn't eliminate the possibility they might act the same way under certain circumstances. You might look into a Dynojet jet kit for your bike, might make dialing it in easier. http://www.dynojet.com/jetkits/motorcycle/suzuki.aspx

 

[posplayr]

One tooth off on the cam timing and you would not be getting any power at all and you would know something was drastically wrong. I had A similar situation with my bike when I was setting it up for 4-1 pipes and pods. It was too rich and would start stuttering and fowling plugs trying to break through from 3/4 throttle to red line (ran fine up to that point). It finally showed itself one extremely humid hot day and fouled a plug to the point of running on three cylinders. I leaned the main needle one notch and it took care of the problem. I have a different series of carburetor from yours (VM) but that doesn't eliminate the possibility they might act the same way under certain circumstances. You might look into a Dynojet jet kit for your bike, might make dialing it in easier. http://www.dynojet.com/jetkits/motorcycle/suzuki.aspx

if he degreed the cams correctly then the chain doesn't matter.

 

[posplayr]

Hello

My GS1100E -82 still struggling from 3/4 trottle and up.
Feels like it starves for fuel, but I have tried main jets from 130 to 160 with the same results.
It idle OK and further up to this 3/4 trottle problems appear.

Since I have Webcams G2 dialed to 110-110 and 4-1 exhaust AND pods + Dyna-S , my toughts are that it could be something wrong with this cam timing, but I dont think this
should appear at the higher RPM`s ? Anyone ?

Thankfull for any advice for next step...

Knut

If this bike is for the street get the dyna jet kit as suggested and use the largest dj138 mains , but you also need mk47.5 pilots. I would also suggest dyna coils and verify the voltage to the coils. If not good do a coil relay mod.

 

[gsx1100norway]

Thanx for quick response from all of you. !

I already got the 47.5 pilot
But, I think I will try the easiest test first, to check and maybe increase the fuel level in the float bowls a bit as a test.
And might order the Dynajet kit as a second solution.

Thank you all for your help. I`m coming back with the results ....

Knut

 

[John Kat]

I had a similar issue with my GS 1000 fitted with CV carbs, pods and a V&H 4 into 1 exhaust.
In fact I had started with a Dynojet kit and after so many changes, I discovered that the needle provided with the kit will not work with a European spec CV carb...
For a long time, I thought the engine was too lean above 1/2 throttle confirmed by a test on a roll bench but...in fact it was too rich!
My engine is now close to perfect with a 142.5 Mikuni main jet, needle in 3rd spot and 47.5 idle jet.
I will try a 137.5 main jet to confirm I'm right on.

 

[wymple]

Have you adjusted the midrange? It made all the difference on mine, same problem.

 

[posplayr]

Your configuration is very close to many 4:1/Pod mods on a generally stock 1100. So I would go to the known jetting and start searching other things from there. That includes checking the floats, after that I would look at the ignition.

I assume plugs look OK as well?

 

[posplayr]

I had a similar issue with my GS 1000 fitted with CV carbs, pods and a V&H 4 into 1 exhaust.
In fact I had started with a Dynojet kit and after so many changes, I discovered that the needle provided with the kit will not work with a European spec CV carb...
For a long time, I thought the engine was too lean above 1/2 throttle confirmed by a test on a roll bench but...in fact it was too rich!
My engine is now close to perfect with a 142.5 Mikuni main jet, needle in 3rd spot and 47.5 idle jet.
I will try a 137.5 main jet to confirm I'm right on.

John,
It sounds like the GS1000 and GS1100 are quiet a bit different. My carbs are Canadian and then have always jetted very similar to the US ones. Can't say much for European version of BS36 carbs.
Jim

 

[Guest]

Hello

My GS1100E -82 still struggling from 3/4 trottle and up.
Feels like it starves for fuel, but I have tried main jets from 130 to 160 with the same results.
It idle OK and further up to this 3/4 trottle problems appear.

Since I have Webcams G2 dialed to 110-110 and 4-1 exhaust AND pods + Dyna-S , my toughts are that it could be something wrong with this cam timing, but I dont think this
should appear at the higher RPM`s ? Anyone ?

Thankfull for any advice for next step...

Knut

You need to lift the needle up and put the 147.5 back in it. Make sure you did not kink or have the fuel line turning to sharply
And on another note move those cams back some to 106 intake and 108 exhaust and you will be much happier

 

[Guest]

Your configuration is very close to many 4:1/Pod mods on a generally stock 1100.

No kidding. I am running pods and a Kerker 4-1 on my Canadian model '82 1100E and have 47.5 pilot jets, 142.5 mains, OEM needle on 3rd groove and mixture screws 3 turns out. Elevation here is ~3600ft if anyone cares. If OP went from a 130 to a 160 main jet and didn't notice a difference something else is causing his issues.


Mark

 

[gsx1100norway]

I tried as follows yesterday:

Raised the fuel level 1,2mm ( 21,2mm )
Main jet 140

A LOT better from 3/4 and up, but still minor hesitations . I think we now are talking minor needle and maybe main jet adjustment, I will test this tonight.
Seems that fuel level was the major problem together with minor jet size/adjustment.

Thanx all for help
Will keep you updated in the progress....

KnutK

 

[gsx1100norway]

What about the "AIR JET " in this setting, it`s functions also at 3/4 to full trottle as far I can see .... ? :-/

Knut

 

[John Kat]

I tried as follows yesterday:

Raised the fuel level 1,2mm ( 21,2mm )
Main jet 140

A LOT better from 3/4 and up, but still minor hesitations . I think we now are talking minor needle and maybe main jet adjustment, I will test this tonight.
Seems that fuel level was the major problem together with minor jet size/adjustment.

Thanx all for help
Will keep you updated in the progress....

KnutK

The theory with CV carbs is that you start ajusting the main jet first (at full throttle)
When that works you work the needle up or down and then you sort out the idle jet.
If you don't follow that order you'll be going around in circles.
Guess how I found out!