evinrude fleetwin 7.5 HP wont stay running only on fast

[duckland23]

My evinrudefleetwin 7.5 hp 1957 wont stay running for long or will it idle down in slow speed if I turn the tiller handle, just fast speed and sometimes not much . . Im unsure if the low speed jets or passages are pluged up . Should I rebuild it and clean the carb , I have the kit for it from napa auto parts . I know there's a filter bowl under the carb and its full or can it be the pressure tank not working right .


I did'nt change the points and condenser on this motor or did i rebuild the carb on it at all Ijusted looked at them , they looked ok .. I have the kit for it and am thinking of taking it apart for cleaning today . I need to get some cem dip in the gallon can to soak it over night . i did not buy the carb kit with the float napa for some reason did not have it for this motor . I had this motor running about a week ago .

Also should I change the o=rings on the fuel conector off the fuel tank . I heard they leak air from bad o-rings . if so what size are those o-rings in it . My auto parts store will have o-rings for it . How would I get it apart . I seen a guy use a punch to remove the square metal block in it along with the spring . Im going to start with rebuilding the carb first and then the o-rings in the fuel conector . The fuel line is ok and I think the tank is holding air . But i seen some bubbles at one of the screws . Should I tighen it up . or rebuild the tank with a new kit . were would you start at .

 

[JDusza]

Re: evinrude fleetwin 7.5 HP wont stay running only on fast

Welcome!
Well, ... if it were me, I would put the time into a thorough check-up; compression, spark and fuel. Even though the overall symptoms sound like fuel delivery, a look at compression and spark will remove doubt. The fact that it runs indicates there's a lot o' good somewhere.
The symptoms sound like it is suffering from poor fuel delivery. This is a two-hose-tank-to-engine system, right? Air leaks in old hoses, poor clamps at connections, pressure and vacuum sides of hoses, plugged low speed carburetor jets, ....
Runs at high speed, right?
The carburetor rebuild is not a bad idea. Be sure to clear the low speed jets by removing the Welch plug (expansion plug) on the carburetor.
So, carburetor rebuild, good hose check-out, good connector check-out, compression and spark because they are easy and basic. Perhaps check tank foot valve assembly to be sure, as well.
That's where I'd start.
Cheers!

 

[duckland23]

Re: evinrude fleetwin 7.5 HP wont stay running only on fast

I think the compression is good the engine has power like all hell anyway . I dont own a compresion gage anymore , I did at one time , but not no more . I think you can rent them from autozone . Compression has to be done on a warm engine for proper readings anyway . So im going to rebuild the carburetor anyways . It dont seem that hard anyway , I may change or take a second look at the engine for proper spark . Two see if both of the cyclinders are firing right , and check for proper points gap . I bought some cem-dip for cleaning the carb the right way over night . I know about the upper welch plug with the lead ball in there , I cant lose that ball or Im out of luck .

 

[duckland23]

Re: evinrude fleetwin 7.5 HP wont stay running only on fast

@jdusza

Where do I get the float from . I talked to napa and they could'nt find the proper number to get the float . Im sure they have it . I need omc number 375919 thats the number in the parts manual from marineengine .com . Now I need the proper float number for napa or there part number so I can order it . But I need to check it to see if its bad , but I bet it is .

 

[duckland23]

Re: evinrude fleetwin 7.5 HP wont stay running only on fast

also Im missing the lead shot for this carburator . its omc part number 304201 . Can I use another lead shot for this carb . I can order one from ebay for 2.00 plus shipping . so what can I do to solve this problem . I bet thats why its not idling right in the first place .

 

[bbstacker1]

Re: evinrude fleetwin 7.5 HP wont stay running only on fast

I don't think Sierra offers a float for that engine (Sierra is what NAPA sells). If it was me and if you haven't started on the carb kit yet, I would return it to NAPA and find an OMC dealer and get the kit with float from them, the part number should be 439071 and it should run around $25-27, Otherwise you will have to buy the float separate. This is of course assuming the float that is in the engine is cork, if it is plastic you should be good to go.

 

[duckland23]

Re: evinrude fleetwin 7.5 HP wont stay running only on fast

the float's good . Its looks very good . But im missing the lead ball from the carb .