57 sportwin running but wont idle

markfromohio

Cadet
Joined
Jan 31, 2010
Messages
16
I finally put it in a tub and fired it up.. I rebuilt the carb and blew everything out with air. I turned it over and the float valve seated and i couldn't blow through it. started right up and runs great at high speed. But when i throttle down it stalls right away. I adjusted the needle valves the way it said in the manual. Says 3 quarter turn on each. And I tried adjusting the low speed valve each way and it doesn't seem to effect it in any way. I did reuse the old float as my kit didn't come with one. any suggestions befor i tear back into the carb?:confused:
 

James R

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Joined
Feb 1, 2007
Messages
2,679
Re: 57 sportwin running but wont idle

If you play with the choke will it try to idle. If it will then the carb is probably still dirty or you have and air leak.
Did you check the compressions. If you are down on one it will not idle.
Did you check for good sparks. One bad spark will prevent idle. Exhaust smoke getting into the cowl will cause bad idle. If it idles with the cowl off then Exhaust getting in is the problem.
This is just a few.
 

markfromohio

Cadet
Joined
Jan 31, 2010
Messages
16
Re: 57 sportwin running but wont idle

If you play with the choke will it try to idle. If it will then the carb is probably still dirty or you have and air leak.
Did you check the compressions. If you are down on one it will not idle.
Did you check for good sparks. One bad spark will prevent idle. Exhaust smoke getting into the cowl will cause bad idle. If it idles with the cowl off then Exhaust getting in is the problem.
This is just a few.

Thanks for the reply.. I put all new ignition parts in. New coils, condensors, points. checked spark and it was good. I am running it without the cowl on, and it wont idle.
 

markfromohio

Cadet
Joined
Jan 31, 2010
Messages
16
Re: 57 sportwin running but wont idle

I have it adjusted now where it will stay running at about a quarter throttle. Then it's like it will start missing and if i give it throttle it will rev back up, but if I dont catch it fast enough it will stall and I have to choke it to get it fired back up.
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: 57 sportwin running but wont idle

When it's about to stall spray a 24:1 fule/oil mix into the carb and see it it recovers. If it does, then it's a fuel supply issue and you need to re look at the carb. If not, it's an ignition issue.
 

markfromohio

Cadet
Joined
Jan 31, 2010
Messages
16
Re: 57 sportwin running but wont idle

thanks I will try the spray bottle tomarrow after work. It's 8:00 and my nieghbors are old. I did a compression check and both cylinders were at 85 I think thats low compared to the numbers I have seen on here. could that be the problem?:confused: Plugs were wet too. maybe i am getting too much fuel.
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: 57 sportwin running but wont idle

85# each is fine. It'll run well like that. Wet plugs could just be from trying to start it to much. Try the spray and see what happens...
 

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: 57 sportwin running but wont idle

Says 3 quarter turn on each.

Low speed should be open 1.5 turns to start. If it's lean sneezing when you try to idle, open that needle up some. Also, when you rebuilt the carb, did you remove the welch plug on top and clean out the holes underneath it? That's the low speed circuit and if those holes are plugged, it won't idle good.
 

coolguy147

Commander
Joined
Jul 14, 2008
Messages
2,817
Re: 57 sportwin running but wont idle

clean the carbs? replace your impeller? do a link and sync yet?

replace your float? check float height? replaced gaskets in carb? fuel lines(can blog carbs if old)?
 
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