GS1150ES Dies When Throttle Opened

[Flyboy]

Sounds like the idle circuit is not carrying it onto the intermediate circuit (needle).
Or your intermediate circuit is too rich or lean and giving you a rich cut or lean cut as it comes in.
Try going richer on your idle, to carry it further up the range and allow the needle to take over.
If no joy, try moving he needle up and down a slot and see what happens.

 

[londonboards]

Flyboy - thanks for that but my needles do not have different clip positions. I think the only way I can change the position of the needles is to shave some material off that plastic washer on the top of it. But it is all stock now - at least I think those needles are?

Greetings

 

[Paul]

Maddevill - slides stuck? Never thought of that. Can't remember checking them though. All diaphragms were good. I'll take the top off one of the carbs and see if it moves.

Greetings

I had the same problem on my G when I got it, but never identified it fully as I already had a set of clean carbs to throw on instead

I 'm with Madevil.... something's not clean,, did you use compressed air after the U/S cleaning?

make sure those slides are silky smooth

 

[londonboards]

Checked Slides, Airbox and Fuel Bowl Level

Checked Slides, Airbox and Fuel Bowl Level

OK so I am no nearer to guessing what is causing this to happen.

Airbox is secured. Slides glide up and down (I took the tops off to check) and I jammed a plastic hose in the float bowl drain and saw the fuel level rise to near the top of the float bowl. So there is enough fuel to cover the main jet. Why won't fuel get sucked up into the main jet when the throttle is opened?

I am guessing this is not electrical as it is possible to rev the engine when cold using only the choke. It will go up to 5K like that so I know the spark is there at that speed.

Help.

 

[Agemax]

have you checked valve clearances and engine compression?

 

[londonboards]

It will rev to 5K under choke and when it is warm it idles nicely. Would it do this with bag compression or badly adjusted valves? Just absolutely zero take up when throttle opened even a small amount.

No I haven't. I will do valves next. Don't have a compression tester. Might be able to borrow from Tatu.

Greetings

 

[Agemax]

you are running out of options with the carbs so you need to explore other possibilities.
have you put vacuum gauges on it yet?

 

[londonboards]

Need to borrow some of those as well!!

 

[Agemax]

was the bike running ok when you first got it?

 

[Flyboy]

It will rev to 5K under choke and when it is warm if idles nicely.

That, right there tells you it is a lean cut problem, increase those idle jets and lift the needle if you can.

 

[londonboards]

flyboy - so it would cut completely? I have re-jetted back to standard and have a complete and secure airbox. I don't have clip positions on my needles (perhaps I have the wrong needles) so I can only adjust by sanding the plastic disk.

But surely as it is near original spec I should get some throttle response? I agree that fine tuning might require some adjustment. I think I will try another set of carbs?

Greetings

 

[londonboards]

Agemax - It is was a non runner. I did the carbs and now have it running on idle only.

Greetings

 

[Agemax]

you reverted back to standard airbox but you still got that 4 into 1 on it. stick the bigger pilot jets back in....... you may still need to up the mains a bit.
try refitting both the mains and pilots back in and see how it runs then

 

[londonboards]

Agemax - I think I have an attitude to my problem!! I just don't want to believe you would get nothing, zippo, nil throttle response just because main jet is a size or 2 out. Flat spots - yes. Nothing - no.

I'm just a beginner - what do I know? Those carbs are coming off again this weekend.

Greetings

 

[Guest]

Pull out a jet needle and give us the number.

 

[posplayr]

If the bowels are full of gas are the bowels vented or for some reason did to block the vents?

Even when you idle it up it doesn't sound right and the stall is saying it is not sucking any gas.if you mist gas into the input with throttle slightly open it should rev to confirm it is carburation and not something else.

 

[Agemax]

Agemax - I think I have an attitude to my problem!! I just don't want to believe you would get nothing, zippo, nil throttle response just because main jet is a size or 2 out. Flat spots - yes. Nothing - no.

I'm just a beginner - what do I know? Those carbs are coming off again this weekend.

Greetings

the larger pilot jets will have a much bigger effect at very low throttle openings. maybe required to suit that 4into1 you have fitted.
i said "try" the mains as well just to see if it makes a difference!

 

[Nessism]

You shouldn't need larger pilot jets if the only change is the pipe. The bike may need larger main jets though.

 

[londonboards]

Works Really Well When Needles Assembled Correctly!!

Works Really Well When Needles Assembled Correctly!!

See My GS1150 Blog for bigger pics.

I took the carbs off to see what the blazes was going on:

All the bowls had a decent amount of fuel in them:

Even though little tangs bent quite a bit:

There were still within spec:

Could the needles be a problem? They are quite low in the emulsion tubes:

I took the needles out and compared them to another set of carbs I have. This is what I found:

All four needles had been assembled with the spring on top rather than under the circlip. I am putting my hand up as being responsible!! I had never taken needles out before this rebuild and they sprung apart on me so I was not able to see the order of the parts. Should have checked the workshop manual. Or had the PO assembled them like that? He just might have ......

Here is proof that the problem is solved:

http://www.youtube.com/watch?v=1_TBzd6iy-E&feature=share&list=UUyXuswL_dnnw0DGg15QawlQ&index=1

Greetings

 

[Rob S.]

Beautiful looking (and sounding) bike, mate.

Now throw a seat on her, throw a leg over her, and show us what we want to see: movement. 0 to 100 (160, I forgot you're 'down under').