1971 9.5hp Evinrude Sportwin Carburetor Issues

[tedstevens]

My 1971 9.5hp Sportwin Evinrude has been driving me nuts! First off I use to have a lot of issue with it cutting out of power and all kinds of things, took it to my local mechanic and said it was because the float in the carb had broken up into pieces because of the dang enthanol they are putting in gas these days, so I have him make me a new float made of materials that wont break up with the new gas these days. Take it out to the lake and it runs like a champ for like 4 hours, full throttle, idleing and everything this thing is working great. Take it to the lake the next day it starts right up after two pulls I get it off the trailer tie it up to the dock to go park the car so of course I shut it down. Then when I get back it will not start for anything, tried choking, i tried different throttle positions it just won?t crank. But I didn?t mess with the idle fuel mixture knob thinking that won?t help anything being it worked great the day before. So I pull it back out of the water and take it home. Well I first tested the fuel line going into the carb and when I pump the bulb it shoots out gas, so the carb is getting fuel. So I put a little gas into the bowl of carb and cranks right up and runs just for a couple seconds, and then it shuts down again and it won?t start, unless I put fuel in the bowl of the carb. I thought I had new fuel nozzles put in the carb last year? So could it be the nozzles? And are you suppose to replace those things more often than once a year? What can I do here? I was hoping that iWombat had some wisdom he seems to be the guru on these motors! Or anyone else that could help would be much appreciated!

 

[deeman7777]

Re: 1971 9.5hp Evinrude Carb Issues

Re: 1971 9.5hp Evinrude Carb Issues

I just picked up one of these motors too and I am learning it too.

I would suspect your fuel pump could be bad - especially if you are able to run the motor by putting bas into the float.

I just picked up a Siera aftermarket fuel pump for $40.

Seems these fuel pumps may be a weak link and have delicate components which can, and do, wear out.

I'll let others chime in to see if my suspicion is correct.

Mike

 

[tedstevens]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

Where did you buy your fuel pump? And is there a part number i would need? Thanks!

 

[Rick.]

Re: 1971 9.5hp Evinrude Carb Issues

Re: 1971 9.5hp Evinrude Carb Issues

I often wish I was born before the advent of the internal combustion engine. They can be very frustrating to say the least. I don't like to fly for the same reason.

I would suggest you pull your carb. apart and have a look at that hand made float. Your symptom is that your carb. is not providing gas to the cylinders. The cork floats will probably work better than something hand made of composite material. A new high speed nozzel should last a lifetime but if it's dirty it won't work worth beans. Pull your carb. and have a look inside for something obvious and let us know what you find. As a side note I have ordered carb. kits that come with a new composite float to replace the cork float but I recently ordered a new OMC kit for my 9.5 and it came sith a new cork float. It also came with an upgrade that now attaches the needle to the float arm like most carbs. have where the old one had the needle just floating on top of the float brass arm. I like the attachment way better. I would also recommend replacing your gas line from the connection point to the carb. Best of luck. Rick.

 

[ezeke]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

Fuel pumps just fill the float bowls and your symptoms sound like it is the carburetor again. You may have picked up some debris and blocked the high speed jet.

Anyway, set your portable tank higher than the engine and gravity will feed the fuel as well as the fuel pump, so you can tell if that is the problem.

You can remove the drain plug from the float bowl and reach the high speed jet; it's located in line with and just behind the drain plug.

If you do take the plug out, put a rag under the carburetor first; things that fall into the 9.5 are never seen again.

Make sure that you replace the float needle and seat as a unit and that the clip is in place between the float valve needle and the float arm.

 

[tedstevens]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

The fuel pump is working because i took the gas line off of the carb and then tried to start it and fuel started spitting out of the fuel line, so the fuel pump must be working fine. But i went ahead and went down to my local dealer and picked up a carb rebuild kit and im just gonna rebuild the whole carb tonight. anyone have anytip to using one of these kits. Or i guess i can just do a search and im sure ill pull up alot of info! You guys have saved me so much time and money and being a poor college student that likes to get out and fish! This forum really has eased my pocket book!

 

[ezeke]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

You will need to turn the tiller handle to get to the fifth screw when removing the carburetor, otherwise it is pretty straight forward. A can of aerosol Gumout will help if you don't have an air compressor.

Try not to get solvents on the nylon parts.

Don't remove the three lead shot plugs.

Turn the lean/rich knob clockwise until it gently bottoms, counting the exact amount needed to get there, then record it so that you can reset the needle back to the same point you started after cleaning the seat.

 

[tedstevens]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

Okay, this a total newbie thing, i guess these "shot plugs" are little round things plugged into holes to keep them from leaking?

 

[ezeke]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

Yes, click the thumbnail.

 

[Rick.]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

Pulling your high speed nozzel can be difficult if you don't have the right tool. IYou need a flat screw driver with a 3/16th. wide blade and shaft. Any wider and you could bugger the channel walls any smaller you could bugger the high speed jet as the screw driver will fall off the nubbs and perhaps break the brass away. If you don't have the right one, leave the HS nozzel in place and clean through it. I use cans of pressurized carb. cleaner. Wear glasses and after breaking the carb. down spray every possible orific you can find on the car. from both directions. Make sure you clean every possible channel. Once your convinced you've got it clean follow up by spraying compressed air both ways through every channel. Be very careful as to what part goes where. Take didgital pictures and/or write things down. Carb. cleaner eats plastic so be careful. Once cleaned put the fittings back together and re-install you carb. Best of Luck. Rick.

 

[tedstevens]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

Everyone thank you so much! If you guys lived in the Dallas, TX area i would take you out for beers!

 

[tedstevens]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

Thanks for all the help! You know i couldn't find the high speed nozzle, i looked at the carb part diagram at the Evinrude/Johnson diagram site that list all the part numbers. There was no mention of a high speed nozzle only a slow speed nozzle. But anyhow i cleaned out the carb with aerosol carb cleaner and then i blew it out real good with an air compressor and installed all the new parts that came with my carb rebuild kit. It started right up! I still need to take the boat to the lake and test it with a load, but i seemed to work great just being cranked up real quick at the house. Thank you for all your help! It made this little project some much easier.

 

[Rick.]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

High speed nozzle is part number 32 and called an orifice plug. Hopefully you got it clean without removal. Sorry about the wrong part name. Rick.

 

[TylerS]

Re: 1971 9.5hp Evinrude Sportwin Carburetor Issues

Yes, click the thumbnail.

I have the same motor, what are the two small open holes going into the carburetor. On is the opposite end of the top hole with a lead shot filling. I have gas coming out of that hole and can't figure out what's the problem.

 

[racerone]

The float valve needs attention.-----But best to start a new topic on these pages.----The site gustapo will be along soon.

 

[todd281]

I would suggest checking out a site called" Leroys ramblings" , lots of good, free info there on 9.5 Evinrudes

 

[Crosbyman]

http://www.leeroysramblings.com/OMC_9.5.htm

 

[GA_Boater]

The float valve needs attention.-----But best to start a new topic on these pages.----The site gustapo will be along soon.

You're right - Assume the position. :facepalm:

But this thread is only 9+ years old, little more than a year using doggie time.

Closed.