[89gxrslingshot]

Hi all,

Bought an 89 GSXR slingshot about 6 months ago and have been working though a list to get it roadworthy. As part of the list I had to replace the throttle cable and repair kinks in fuel lines, so have had tank off, hoses off air cleaner out and a few other bits and pieces.
Finally got it all back together this morning and have been trying to start but can’t get the thing to fire at all.

Things I’ve tried.

• removed all 4 screws on bottom of carb bowls to see if fuel was there. Drained what was in bowls but no more fuel came out when fuel tap was in each of the 3 settings.
• lifted tank, as there looked like there was still a small kink in one of the lines, made sure all lines were straight but still wouldn’t fire and still nothing out of the carby bowls.
• Removed plug leads and fired with a spare plug in, had spark so doesn’t seem to be a spark issue.

Bike started and ran fine when I first got it, but on the way to the mechanics for the roadworthy (6 months ago), the throttle stuck on, not sure if this has any relevance??

Trying to avoid pulling carbs out and rebuilding, but thinking that might be the next step.

Any help or ideas would be awesome!!

Cheers

 

[Beairsto Racing]

Your petcock should flow when in the "On" position, if you provide a vacuum.
It should also flow freely when in the "Prime" position.

I'd start with that, then you can look at float heights etc.

 

[TwistedMister]

when you lift the tank and remove air box you should be able to inspect the throttle, if its stuck you will see it, the throttle arm wont move and the butterflies wont open, or close whatever the case might be?

you could rig up a tee right at the fuel rail inlet, run a hose off that tee too a bucket then check your fuel pressure so forth with the tank down.. that should sort that..manual has pressure and flow specs..

then you might have to pull the carb rail and soak, inspect and replace anything off, your fuel needle valves may be sticky, todays gas plays havoc on these old carbed bikes try to run an ethanol free (pure-gas.org) aviation or make your own e free, videos on youtube real simple , at least for those storage and long durations in between rides, saves on rust and corrosion, rubbers parts.. yup, lest get a half cup of seafoam in there and mix it real good for storing or sit periods..

maybe try some ethanol into the carbs see if it fires on that..

 

[89gxrslingshot]

Thanks heaps for your answers guys.

Spent a bit of time checking out what you mentioned over the last few days. Removed tank and found all hoses to be bone dry. Turns out the petcock is no good and needs replacing. After opening it up I’ve noticed there is wear in the section when it turns to prime, there for not allowing it to open the fuel tap at all (as the other 2 settings only work if there is vacuum pressure).
I’ve ordered a new factory petcock from a place in Melbourne, only an hour away from me.
Fairly confident this will fix the issue of not starting, but going to rebuild carbs when I get a chance too, as bike has been sitting for a while with previous owner.

Thanks again guys!! Really helped

 

[TwistedMister]

PROPS, hoses are all in good shape right? can you get any seafoam into the carbs while you wait on parts? then celan that tank out real good no particulates or rust.. then remove the bowl screws on carbs and flush when its all hooked up, let it flush well, sea foam will help loosen stuff up and clean em out

you can rig a funnel to the fuel inlet hose and prop it up good and solid so it wont move.. fill carbs and maybe a few cranks with spark plug out get alil vacuum going,let set overnight, do like a 25% sea foam to 75% gas mix, flush each day till parts show up, celan tank in the meantime as well get it all ready to go..

generally when the petcock is gummed a lot of stuff is gummy and funky, fuel deedles sticky and gunky.. might be a good idea to start saving fora carb rebuild and good sonic soak in yamalube carb cleaner.. carbs are real heavy maintenance heavy items these days.. run E free of possible, or at least to store it, for anything over 3 weeks or so.. really helps save your carbs and fuel system..

 

[86gixxxer]

best of luck and keep us updated.