62' Johnson 28 hp RXL-10

[Zac2424]

I have been fixing up this motor for a few years now and have some questions.

The motor runs very strong and starts up on the first pull. I have a starter, but it doesn't work and i haven't had time to get it refurbished. It also had electric choke, but I have never been able to get it to work. I have not replaced points, condensors, impellor, coils, etc. because it pumps good water, has good spark and seems to run well. I have cleaned the carb twice and seems to be pretty clean and working properly.

My question is why the motor will not get to full speed. When we take off it gets to about 1/2 speed and will not go any further. If we go for a while i can mess with the throttle back and forth and sometimes...very rarely it will take off at full speed and run great! At 1/2 speed it doesn't run bad, just not near as fast as it should.

What would cause this? I don't think its my cables because when i disconnect them and use the motor trottle switch it will not turn all the way over.

Is this motor electric shift? I never have it connected to a battery, but when i do and turn the switch to the on position it does change the motor sound and how it runs but still usually no full throttle. I am wondering if i need to get a manual and link and sync this thing or what...really don't know what to do from here.

Any help would be greatly appreciated.

THanks

Zac

 

[bktheking]

Re: 62' Johnson 28 hp RXL-10

You contradict yourself by saying it runs well yet it won't go as fast as it should. Have you inspected the condition of the coils, points and such? It doesn't take much, if the points are out a bit or severly worn timing is off, if the points are dirty spark can come and go. If you are planning on keeping the motor i'd bite the bullet, pull the flywheel and replace some parts, wires- points/condensors- possibly coils if they are cracked. Did you also look to see if the carb butterfly is opening fully at full throttle. Carb linkages can slip and i've also seen wear where the carb is controlled by the mag plate. What about compression, is it good on both cylinders?

Welcome to Iboats!

 

[Zac2424]

Re: 62' Johnson 28 hp RXL-10

I didn't mean to contridict myself, it runs smooth at 1/2 speed and runs smooth and strong with it final goes to full speed, but never seems to get there very often. From ready posts on here for a year or so I thought i could rule out points, carb, and stuff like that but you are probably right i need to break down and get dirty with this engine.

I have never checked the compression, and I do not have a harmonic balancer puller so i have never pulled the flywheel and checked underneath. I have just read of a couple guys bending the flywheel or messing up something unintentionally.

Does anyone have a photo of underneath the flywheel and what i should look like, because i will bet i have no idea.

 

[bktheking]

Re: 62' Johnson 28 hp RXL-10

Have a look at this post:

http://forums.iboats.com/showthread.php?p=2086934

Old vs new, you will need a puller and some grade 8 bolts, torque wrench, some form of gap tool to set the points, screw drivers and some pints!

 

[F_R]

Re: 62' Johnson 28 hp RXL-10

Zac, there is no doubt about it whatsoever---your motor is running on one cylinder. First you should check the compression to make sure you have a good motor to fix.

Then you need to get that flywheel off to fix it. You are right, you can severely mess it up if you do it wrong, so do it right the first time.

OK, down to the nitty gritty---You said "Is this motor electric shift? I never have it connected to a battery, but when i do and turn the switch to the on position it does change the motor sound and how it runs but still usually no full throttle. I am wondering if i need to get a manual and link and sync this thing or what...really don't know what to do from here."

No it is not electric shift.
"When you turn the key on, it changes the sound." Hey, it shouldn't run at all with the key turned off. You must have it wired incorrectly OR you have the WRONG key switch. This may be a clue as to what your one-cylinder problem is.

 

[jasper60103]

Re: 62' Johnson 28 hp RXL-10

Zac,
send me a PM with your email address. I can send you a service manual for your motor.

 

[Zac2424]

Re: 62' Johnson 28 hp RXL-10

Okay so it's manual shift, that is what i thought. But it definitely runs different whent he key is in the on position. But it doesn't kill the motor when off, i have to choke the motor out each time to kill the motor. I believe both cylinders are firing, because i thought that was my problem. When i unhook the bottom only spark plug it runs, and when i unhook the top only spark plug it runs, so i dont believe it is that one cylinder isn't firing. But i don't know, maybe at full speed it is not firing??

I'm getting a compression tester and a harmonic balancer puller tonight to pull the flywheel after i check the compression. How exactly do i check pressure when the gauge is on there?? I've heard 1 pull of the chord and i have heard around 6 pulls, any advice?

Thanks!

 

[F_R]

Re: 62' Johnson 28 hp RXL-10

Well, ok so it isn't running on one, as evidenced by your plugs disconnect. You better check the throttle linkage. Make sure the spark advance is going all the way against the stop and the carburetor is opening all the way.

How far do you have the high speed needle opened? Is it chugging along, too rich? Have you tried adjusting it?

The easy stuff has been covered, now we are down to guessing.

Disconnect the wire harness till you get it running right, then worry about the switch and stuff later. It will run without the electrical.

 

[Zac2424]

Re: 62' Johnson 28 hp RXL-10

I do think there are some issues with the throttle on the motor. There is a plate that moves around the central shaft and touches the shift arm, and there are some small wire mechanism on the opposite side that move with the throttle. I have no idea how to adjust them or if they are correct or not. The carb should be set right the low is out about 1.5 turns, and the high probably around 7/8 of a turn. It seems to idle and run good, its like the throttle will not engage all the way. Very puzzling. The carb seemed to work just fine the last time i had it apart.

 

[bktheking]

Re: 62' Johnson 28 hp RXL-10

Pics of the setup would certainly help.

 

[Zac2424]

Re: 62' Johnson 28 hp RXL-10

Well i got the flywheel off last night finally with no problems. Sorry no photos until tonight after work, but after looking everything over it all look like it was in pretty good shape. I do have a tune up kit i will put in just to be safe. I did notice one of the points was closed completed, it was touching completely and had no gap between it and the contact. The other looked okay but i will definitely check the gap. Could that have been my problem all along?

I think where most of my problems lye is the throttle linkage. When i open it up to full throttle the plate doesn't rotate all the way around against the stop plate. I can move it over easily by hand, but the throttle controls alone will not move it over all the way, thus i am guessing no full throttle. Any thoughts?

Thanks!

Zac

PS i will get some good photos to better explain tonight.

 

[Zac2424]

Re: 62' Johnson 28 hp RXL-10

Replaced both points and regapped at .03, regapped the plugs at .02 and freed up the binding throttle linkage the other night. I tried testing the motor in a trash can of water but it was too small and really giving me problems, so i am going to try to take it to the lake for a test run this weekend. I also checked the compression and i had 90psi on top and 80psi on the bottom cylinder. Is that okay? I am hoping that these changes will help. I did notice while trying to use the trash can that there is some oil and black goopy stuff coming out of the water exhaust hole into the water. Is that a bad impeller or do you think i have some kind of leak somewhere?

Any advice would be greatly appreciated.

Thanks!

 

[bktheking]

Re: 62' Johnson 28 hp RXL-10

Black goopy- probably unburnt 2 stroke, the oil oil what you are seeing, if it was running on one cylinder before it will take a while to clean it out as far as compression a 10psi differential isn't great (you want them close), check the top secret files for tips on doing a decarb, it may just be some carbon buildup or a sticking ring.

 

[Zac2424]

Re: 62' Johnson 28 hp RXL-10

I finally got the motor in a good trash can and was able to get it idling very good in neutral. That is the best it has idled for me ever. Usually i had to have it at about 1/3 throttle or it would die. Hopefully it idles good in FWD. I got the seafoam yesterday and some new plugs and i am going to decarb it and run it up to the lake to get all that seafoam ran through it this weekend.

I will let you know if the compression levels out a little bit.

THanks!

 

[Daviet]

Re: 62' Johnson 28 hp RXL-10

Did you really gap the points at .030", should be .020" and the plugs at .020", should be .030", if so you might want to reset them.

 

[Zac2424]

Re: 62' Johnson 28 hp RXL-10

Yes i gaped the points at .03 and the plugs at .03, and realized that the plugs should be .02 and reset them. I am still getting oil in the exhaust water when it runs, hopefully that will clear up...

 

[btaylor507]

Re: 62' Johnson 28 hp RXL-10

Quote: "I did notice one of the points was closed completed, it was touching completely and had no gap between it and the contact. The other looked okay but i will definitely check the gap. "

I'm not sure if this was mentioned or if you know but there should be one set of points touching at all times. The gap is measured on the high point of the shaft. (.02 most likely). Also make sure those points are clean. Not even a fingerprint.

Good luck!
-Bill

 

[Daviet]

Re: 62' Johnson 28 hp RXL-10

Reread my last post, you have the gaps wrong.
Points = .020"
Plugs = .030"

 

[bktheking]

Re: 62' Johnson 28 hp RXL-10

"Yes i gaped the points at .03 and the plugs at .03, and realized that the plugs should be .02 and reset them. I am still getting oil in the exhaust water when it runs, hopefully that will clear up... "




Plugs should be .030 and points .020, you reversed your gaps so to speak

 

[Zac2424]

Re: 62' Johnson 28 hp RXL-10

Okay i will double check to be sure: Plugs .03, points .02.

Yes, originally the backside point contacts were touching. The front point contacts were not. I spaced gaps between each of them. Was that wrong? I thought they both had to be gapped. If the back one is not how does is work? I am gettting really confused now...