82 johnson 115 won't go over 3000 rpm

[baysport]

Boat was running great....ran out of gas and now will not go over 3000 rpm's, anybody have any ideas?

 

[reeldutch]

Re: 82 johnson 115 won't go over 3000 rpm

there might be some crud in the fuel system,
you have a aluminum fuel tank?
could be:

- clogged fuel filter
- dirty main yet
- clogged anti syphon valve
- high vacuum in the fuel system
- air leak in the fuel system

 

[ezeke]

Re: 82 johnson 115 won't go over 3000 rpm

What kind of fuel filter do you have?

Try to borrow a portable tank with a clean fuel hose and bulb and see if you can get to WOT. Saves a lot of time.

 

[baysport]

Re: 82 johnson 115 won't go over 3000 rpm

thanks guys i will try that when i get home.

 

[baysport]

Re: 82 johnson 115 won't go over 3000 rpm

Changed fuel, replaced filter, new spark plugs. Still doing the same thing. When I checked the spark plugs, after a test run on the lake, the bottom right plug has a little fuel on it but no burn, looks brand new. Any ideas will be greatly appreciated.

 

[TD_Maker]

Re: 82 johnson 115 won't go over 3000 rpm

This is going to sound real stupid; however, this happened to me.

The 115 V4's have 2 latches which hold on the motor cowling (backside) When removing or installing the cowl, the latch hooks have a nasty habit of grabbing or hooking the wire connector to the coils and/or power pack, along with the plug wires. Check for loose connectors or broken wires in these areas. A motor running on two cylinders would only produce 3000 RPMs (if you are lucky)

 

[ezeke]

Re: 82 johnson 115 won't go over 3000 rpm

The probability is that you will need to rebuild the carburetors. If you order the two kits you will save some more time:

http://www.iboats.com/mall/partfind...&keywords=carburetor kit&**********=580169238

 

[johnson1989]

Re: 82 johnson 115 won't go over 3000 rpm

I am with TD on this one. Check spark and Compression. My bet is that you have 1 one cylinder not getting spark. I had the same issue after replacing some things. Wire had a small crack and it was sparking to the cowling latches. Running out of fuel could have also pulled up some crud from the bottom of the tank.

 

[hoeser]

Re: 82 johnson 115 won't go over 3000 rpm

TD_Maker: Damn right, same problem on my 140 with snagging plug wires with the cover! When I rebuilt it I tied all the wires back to the heads with zip ties, it's pretty slick that way. I recommend you do the same, takes 15 seconds and 15 cents and its certainly worth it.

 

[baysport]

Re: 82 johnson 115 won't go over 3000 rpm

thanks for the input, i'll get after it tomarrow and post my findings.

 

[baysport]

Re: 82 johnson 115 won't go over 3000 rpm

Ok men, here is what i have done so far. compression is good, spark plug wires are good, new fuel, new filter, new fuel line, new filter and new spark plugs. What next? Power pack, coil something else? What test can I run to find out? Please help! Thank, Brad

 

[baysport]

Re: 82 johnson 115 won't go over 3000 rpm

Any Ideas Fellas.

 

[iwombat]

Re: 82 johnson 115 won't go over 3000 rpm

Have you tried a second tank yet? Could still be an anti-siphon valve or the like. Best way to eliminate anything external is another tank and hose.

 

[redfury]

Re: 82 johnson 115 won't go over 3000 rpm

Did you actually verify spark on all 4 cylinders? I'm working with a friend on a 71 100hp 'Rude and it wouldn't run faster than 7.5mph in the water. Ended up being that one of the brass connections on the 2 points under the flywheel had vibrated loose and had fallen off. Reconnecting it and a little loctite took care of it.

Make sure you are getting spark on all cylinders. If you have a sparkplug that is wet, then most likely it's not firing.

 

[baysport]

Re: 82 johnson 115 won't go over 3000 rpm

I 'm getting good sprk on remaining three cylenders and getting good fuel to them all. Any other ideas?

 

[baysport]

Re: 82 johnson 115 won't go over 3000 rpm

Any thoughts fellas i'm at a loss.

 

[hoeser]

Re: 82 johnson 115 won't go over 3000 rpm

How are you sure you are getting "good fuel" ... I still think reeldutch nailed it with clogged jets.

 

[baysport]

Re: 82 johnson 115 won't go over 3000 rpm

I Getting Fuel To All The Spark Plugs And The Motor Will Run. Could That Still Be The Problem?

 

[Boatnik70]

Re: 82 johnson 115 won't go over 3000 rpm

I Getting Fuel To All The Spark Plugs And The Motor Will Run. Could That Still Be The Problem?

Yes, I would also suspect crud in your main jets. My motor is a lot older (1970 85 hp), but if your carbs are similar, the main jets are right at the bottom of the bowl, and susceptible to crap collecting and clogging them up. You might not even have to invest in the carb kits if you remove the plugs that cover the jets (on the bottom of the bowl) and blow through with carb cleaner and compressed air.

 

[Willyclay]

Re: 82 johnson 115 won't go over 3000 rpm

Just had this problem of clogged main jets on a 2004 Mercury 60HP three-cylinder. Mercury jets are on the side for easy access and was able to clean them with Gumout carb cleaner without removing carbs. CAUTION: Wear eye protection so you don't get a face full of spray! Good luck and post your results.