Suzuki 90 hp idles high after carb rebuild?

[CaptainD101]

hey guys another motor to my collection and another question if any one has some advice. This is a Suzuki 90 hp early 90's v4 with the mukuni double barrel carbs. I pulled the carbs for a thorough cleaning as the motor has been setting for a year since being run. Put back together and bypassed the oil injector to run mix gas now. Turned idle needle screws( rich/ lean screw) to about 1 3/4 turns out from seated and cranks instantly with the choke and sounds very strong. Buutt.. just a bit to strong I would guess about 400- 500 rpms to high at idle.
There not many adjustment screws that I see. Theres the screw at the top of the throttle linkage but that adjust the butterflies at idle but its back off all the way, when i screw it in the idles higher. Besides that there's just the idle adjustment screws that I set according to my mercury experience, but what is it for these mikunis on the suzuki
heres the video of it running
http://youtu.be/3hvVyPqr9VE

 

[CaptainD101]

Re: Suzuki 90 hp idles high after carb rebuild?

maybe this is correct idle speed and its just a strong v-4. Just seems a bit high compared to the other outboards I have. and that the prop is spinning to much in neutral is another sign to me. but I dont have a tach hooked up yet

 

[hsdtech]

Re: Suzuki 90 hp idles high after carb rebuild?

Make sure you don't have an air leak where the carbs meet the manifold.

 

[99yam40]

Re: Suzuki 90 hp idles high after carb rebuild?

pick up a service manual for the motor and hook up a tach. Hard to guess at rpm

Check to see if timing is in spec, that will cause higher idle RPMs

 

[Ldavidgrover]

Re: Suzuki 90 hp idles high after carb rebuild?

I'm trying to recall this model. Behind your oil tank is there a small box that is bolted to the lower carb?

 

[Firemanpat01]

Re: Suzuki 90 hp idles high after carb rebuild?

Hi mate, on my 83 60hp Suzuki I have the option of taking the throttle rod/lever of and giving it a wind down , that's helped me in the past, good luck

 

[larryhere]

Re: Suzuki 90 hp idles high after carb rebuild?

HI, not poss. on yours, but the dt v6's have a TPS, throttle position sensor, on the bottom carb usally behind the oil tank! you can bungee the tank back a little bit usally, but be carefull of the little iol injection hose, they get stiff! anyway there are 3 wires with a plug, use a vom or continuity lite, when trottle is closed the green/black should short and the black/brown open until open trotlle! if this the only means of idle, if its open, won't idle down, and only a tiny adj, of say 1/16 inch will throw off, only moves a little bit anyway! if you want more let me know,,, it in the manual!! not in the manual was what happened to me before,,,inside the plug was rusted and didn't make conn.

 

[CaptainD101]

Re: Suzuki 90 hp idles high after carb rebuild?

I purchased this package in such a hurry I didn't even look things through and see there is a good working tach. the rpm's are around 1800 for idle, which I believe is about 1000 rpms too high. I do have a small module on the bottom carb behind the oil tank that also has a linkage going to some type of solenoid below it. I wasnt sure what its function was, Im going to look a little closer tonight to see how its adjusted.

Whats the factory setting for the 4 idle mixture needles for these carbs. ?

 

[larryhere]

Re: Suzuki 90 hp idles high after carb rebuild?

the TPS is in the electrical and ignition section! should show pic,s like mine. if adj or not connecting to the cdi good, thats about where the rpm will stay! worth a check!

 

[James R]

Re: Suzuki 90 hp idles high after carb rebuild?

What scares me is that you " bypassed" the oiling system. The big question is WHY. Suzuki has the most reliable system out there.
Here is the crunch. If you did not remove the pump drive shaft then the pump will run dry and seize, blowing the motor.
A manual is a good investment.