Johnson 4hp problems

[ccolpitts]

I was given a Johnson 4hp motor a while back which ran fine, it's starting to fall apart though. I was wondering if this was a motor worth putting some money into to keep running or if i should think about buying a new one. I don't have a lot of experience with boat motors so some of the problems i have can probobly be fixed with a little time and a manual. Here are the spec's I was able to find on it.<br />MODEL: J4RESR<br />SERIAL: B8436331<br />It appears to be made in Belgium in 1993.<br />Any information on this motor would be grateful. Thanks.

 

[JB]

Re: Johnson 4hp problems

That's a 1990 model, Chris. It was a very good little engine.<br /><br />The only suggestion I have for one that is falling apart is super glue.<br /><br />If it has problems with starting or running, please explain your symptoms and maybe we can help.<br /><br />Good luck, and welcome to iboats.

 

[angus63]

Re: Johnson 4hp problems

I believe you have a 1990. First check compression. If that is good, might be worth the effort. Manuals can be had at www.theoutboardwizard.com<br />Welcome aboard!!!!! If you give it a go, plenty of help to be had here.<br />Where is Round Rock?<br />Keep up the fire!

 

[ccolpitts]

Re: Johnson 4hp problems

The motor only seems to a a few problems runnning.<br /><br />1. Throttle must be at least 50% to keep motor running.<br />2. Throttle must be full to start.<br />3. Sometimes it needs a little ether breakfast.<br /><br />Other than those I haven't noticed anything major. I'm gonna check the compression hopefully sometime this week. I'm hoping these problems can be fix with a little tune up. Thanks for the help and the welcome.

 

[Xcusme]

Re: Johnson 4hp problems

Chris,<br />From your description, it sounds like your carb may need a rebuild. Disassemble carb, soak with carb cleaner, blow out passages with compressed air. Install a carb kit. Pay attention to the Boss gasket in the attached link. The Boss gasket seals the high speed jet from the carb bowl. If this gasket is leaking , fuel will be drawn from the carb bowl (un metered). This will cause an overly rich running motor that won't idle down. <br /><br /> Carb

 

[angus63]

Re: Johnson 4hp problems

Also Avoid using ether and substitute premixed fuel in a spray bottle and a small shot in the carb throat.

 

[ccolpitts]

Re: Johnson 4hp problems

Thanks for the tips, just out of curiosity why is ether bad for the motor?

 

[JB]

Re: Johnson 4hp problems

The ether spray has no lubricant in it, Chris. <br /><br />It will wash oil off of lubricated surfaces and cause abrasion. <br /><br />Enough abrasion and "POOF", engine turns to junk.

 

[davemaxi1970]

Re: Johnson 4hp problems

those engines are super I have had one for twenty odd years and its never missed a beat I use it an auxilery engine and with the reliability of my old 33hp it gets used a lot !!<br />one word of warning Dont mess about with the philips screw on top or your recoil spring will go twang! I learned this from bitter experience they are a pail to put back togther