96 speedster dual 717 carburetor issues

[96 speedster 717s]

I purchased this boat that had been in a garage for several years. Compression was138-140 all cylinders. First issue was lots of oil from exhaust when running.
Lots and lots of smoke. I ran it on the water for a while and smoke and oil finally stopped. I cut back the spark plug wires. Installed new properly gapped plugs. Installed rebuild kits on the carbs.
Set the pop off pressure. Adjusted the carbs by the manual. One engine runs great with no problems. The other will only rev good with about 3/4 choke.
If I hold the choke the boat runs great.
I swapped carbs and the problem followed the carbs. If anyone can please give me something to check based on the 3/4 choke it would be greatly appreciated.

 

[snikwad003]

Perhaps you need to go through that set again. you can also swap one carb at a time and see if the problem follows

 

[96 speedster 717s]

Perhaps you need to go through that set again. you can also swap one carb at a time and see if the problem follows
Thanks good idea, then I can narrow it to one carb. I have a new rebuild kit on the way. I've went through those several times and found no smoking gun.
I'm sure there's tests I could do.
I'll have to do some more Google research.

 

[96 speedster 717s]

I've been trying out the boat without the intakes or flame arrestors. Could this cause any of the problems making me have to apply choke?

 

[Andy4k6]

Would cause issues on the water as others have found however I didnt think it would make much difference on idle however as it's a simple thing to test I would do so.

Sounds like a possible blockage in the carb and it's running too lean.

Andy

 

[96 speedster 717s]

Thanks Andy. Just installed intakes and Flame arrestors I'm going to try it out on the water. Do you recommend soaking in carburetor cleaner?

 

[snikwad003]

Air boxes/ flame arrestors are important to stock jetting

 

[96 speedster 717s]

Thanks Andy and snikwad.
Boat ran better. Now I don't have to hold the choke but pull it out1/4 and it will take off good.
It will run strong as long as you keep it full throttle. If you back off then throttle back up it won't go over 4000 rpms. If you pull the choke briefly it will jump back up to 7000 rpms. I swapped the pto carbs on the water and I've narrowed it down to the one carb thanks to you guys. So now I just have to keep digging into that particular carb. I've took everything out of it sprayed with carb cleaner and compressed air.
Anything else I should do to insure there's no obstruction?
Soak in cleaner overnight or something?

 

[96 speedster 717s]

Update on carbs. I found a set of carbs on Craigslist. Put new gasket set in them and boat is running strong. Not sure what I did wrong with the others.

 

[snikwad003]

Couldbe corosion on the inside you just cant get out