1973 9.5 sportwin, runs on full choke.

[builtjeep]

the motor will run at full throttle with the choke full closed. If I let off of either it slows down then shuts off completely. Open the throttle and close the choke and it'll start right back up.

I've cleaned the carb, and replaced the spark plugs. I checked the compression after it had run for about 10-15 minutes, shows 60psi even on both cylinders.

Any suggestions? I haven't been able to find a tune up kit for it, every place I've looked has been sold out/unavailable. I'm going to double check the point gap this afternoon, but everything looks fairly good.

 

[CATransplant]

Re: 1973 9.5 sportwin, runs on full choke.

How did you clean that carburetor? I ask, because the carb is causing your problem, almost certainly.

 

[builtjeep]

Re: 1973 9.5 sportwin, runs on full choke.

I soaked it overnight in a gallon can of Gunk carb cleaner. pulled it out, cleared all passages with compressed air, re-assembled the linkages, and put the carb back in place. before cleaning the carb it would run only if I poured gas in manually.

 

[builtjeep]

Re: 1973 9.5 sportwin, runs on full choke.

Points were out a little, so I got them set back to .020, didn't make any noticeable diference.

Can anyone tell me how to remove the low idle adjustment needle so I can clean it out? I turned it back and forth a few times and was able to get it to run at closer to 1/2 throttle, but it would still cough badly unless i took it back to WOT.

I also noticed that while I can get it to stay running with the choke open now, it runs at fairly low RPM for WOT, until I close the choke, then it takes off like a rocket.

 

[Mas]

Re: 1973 9.5 sportwin, runs on full choke.

It is still probably a carb issue. There are some very small holes in the carb throat that might still be clogged. Also, your low speed needle may be out of whack. The general idea is 1 1/2 turns from lightly seated...then unscrew 1/16 turn until highest rpm is achieved...then an additional 1/8th of a trun to prevent a lean condition.

I would also use some "Seafoam" to decarbonize your motor to see if you can get those compression numbers up...they're pretty low.

MAS

 

[kenmyfam]

Re: 1973 9.5 sportwin, runs on full choke.

99.9% certain that it is carb related.
Check some posts on cleaning carbs.

 

[kenmyfam]

Re: 1973 9.5 sportwin, runs on full choke.

Did you check this out ???

http://forums.iboats.com/showthread.php?t=244013

 

[samo_ott]

Re: 1973 9.5 sportwin, runs on full choke.

It's the carb probably. You need to fully disassemble it and clean it. Then replace all the gaskets and put it back to gether/. did you remove the lower fixed high speed jet? it needs to be cleaned in there also. Granted the 9.5 has the odd duck carb but I think it's still similar to the older ones.

And 60#'s per side is low. It will run but you will never get full power. Once running you should try a de-carb.