idling problems on my suzuki gsx750

[butcher750]

Hi guys!

I am new to this forum, and not very good with computers, but my son is helping me out!

I have a 1985 Suzuki GSX750EF (I think, could be E or ES)

I am having problems with the idling, because it just won't tick over, even when up to temp. with the choke off. As soon as I let go of throttle, she cuts out.

Is it simply a matter of adjusting the tickover adjusting screw on the throttle valve screw on the carbs, or is it something deeper than that? If it is just the throttle valve screw, is this a simple matter or is it something that would invovle stripping the bike down ie taking the tank off, or even worse removing carbs all together?

Do any of you guys out there know the answer or can point me in the right direction??

[Budgetboy]

idle jet blocked on your carb mate.remove carb and clean.

____________________
www.Mailorderrepairs.co.uk We service your Carburetor's, Calipers & Suspension for less Also Bike repairs undertaken.

[temeluchus]

[Ariel Badger]

It will be a blocked jet, I did a bike last week with tickover issues and when I looked at the jets you could see light but they still needed a blow through with comp air and a tweaking with 0.2mm Cu wire to clear the crap. Runs like a dream now.
____________________
Bikers make great organ donors, get 115 on your licence today.

[Casper]

My money is on a carb clean. Be careful with the pilot jets as the dam things are made of cheese. Only use a tight fit screwdriver as the old heads are easy to break. If unsure get your wallet out and get the pros to do it.

[fireyphoenix1...]

i have a 91 gsx750f .....sounds exactly like the problem i had with a blocked pilot jet .
these bikes have almost run forever engines 99% of the time any running issue is the carbs specifically blocked jets or worn out float valves .

the way i diagnosed which cylinder was giving issue was simple choke off holding it at 1500/2000 rpm for a min then sprayed water on the down pipes 13&4 it boiled off instantly on 2 it took about 20 seconds showing it was a lot colder and not firing properly.
might save you some time if your haveing trouble working out exactly what/where the problem is .
____________________
2014 Aprillia dorsoduro 750 factory.

[fireyphoenix1...]

[temeluchus]

Memory flashback- the mikuni carbs fitted to these motors have detachable float valve seats sealed against the carb body with o-rings. These deform and go brittle over time leak and cause issues starting and idling. Worth checking, if they look squared then they will need replacing.
____________________
Some shite cruiser. Now with guns and FREEDOM!

[butcher750]

Hey Guys,

Thank you all so much for your advice, thats given me quite a bit to be getting on with...- I'm going to trouble-shoot using your advice, see what is going on, and then I'll update you all with my findings, and when she is up and running again properly!

I find the water test on the exhaust down-pipes very interesting, and I shall try this, however, when up to temparature, she is singing on all four, and goes like a rocket with no miss-fire, and also no flat points. Engine cuts out as soon as I stop if I don't keep blipping on the throttle.

If, as I suspect, all I need to do is adjust the idling screw, how the hell do I get at it??!! - Has anybody got any advice on this or any pictorial diagrams??!

Many thanks to you all once again, will keep you all up to date!



Gaz from lowestoft

[fireyphoenix1...]

first things first check the idle it could simply be that the adjuster is turned too far out

you haven't stated if you have had the bike a long time or what so im going to assume that the idle screw is either too far out or missing as in the case of my bike when i got it lol

im not sure what type you have so i will post both the ones i know of

https://img199.imageshack.us/img199/2852/dsci0060r.jpg

on ^these^ idle is the large brass screw in the middle between carb 2&3

https://www.factorypro.com/images/carb_shots/carbfs_36mm_Mikuni.jpg

this large (brass ?)^^^^ adjuster on the left with a cable going to the middle of carbs 2&3 is the idle speed screw the four with red arrows are the mixture screws

hope this helps mate

as for the water test keep high enough RPM to keep it running then slowly close the throttle.
As it moves back on to the pilot circuit the bike should start dropping a cylinder if there is any blockage in carbs this will show you which ones is blocked .

a carb strip and rebuild isnt as bad as people make out i can do it in 20mins now after having done it about 10 times
____________________
2014 Aprillia dorsoduro 750 factory.