Trying to rebuild 18 hp Johnson

[HighTrim]

Re: Trying to rebuild 18 hp Johnson

Cool!

Did you figure out what was wrong?

 

[64osby]

Re: Trying to rebuild 18 hp Johnson

Can't say about the arm plate and flywheel, sorry, still have to try starting mine. It's ready just need to stick it in the water.

Whooo Hooo she runs, what changed to make it run?

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

I did tighten the fuel fittings that attache to the carb. But that was it. I think I just flooded it yesterday. Yesterday I left the choke on for the first 20 or so pulls. Then tried without the choke on. Today I pulled twice with the choke on, And it burped then I unchoked it and it started right up.

 

[kfa4303]

Re: Trying to rebuild 18 hp Johnson

SWEET cc!!!!! Looks and sounds great. My 20 hp i has similar start up. I have to prime, choke, pull, but I have to push the choke in pretty quick, or it will want to flood. After its been up and running for a few min, I usually don't have to choke again for the rest of the day. Usually just pull and go. Congrats again! Vroom-vroom!!!!!

 

[AlTn]

Re: Trying to rebuild 18 hp Johnson

good deal!...get these storms outta here and she's ready for a lake/river test..."ol salt" has that same choke to start, instant off starting procedure

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Hello everyone

Well I finally got to take the motor out for a test run, And It didn't go to well. Motor started fine idled fine. When I put it in gear and started out it felt a little sluggish compared to my 25Hp. I was giving it just a little throttle and didn't get much response. So I gave it a little more. Thats when I really noticed the sluggishness. The boat had 3 people in it and it's pretty heavy for it's size anyway so I thought the motor may just be a little small for the boat. When I tryed to give it some real throttle to go it made a pretty good thumping sound from under the water. And from that point on would not go forward at all. when giving throttle I could see the prop spinning ,but not like it should kinda looked like it was just spinning in the wind in slow motion under the water. Reverse worked a little,but still felt vary sluggish. I didn't try reverse too much. when i got home the next day I pulled the lower unit gears. I meant to take a picture of the LU oil, but forgot it looked like caramel vary milky. So I assumed it most defiantly was getting water in their. After the oil set for a few days in the tub the milky cloudiness went away and it looked regular. So not sure what to think about that. The gears on the other hand have clearly taken some damage. It looks to me that maybe the linkage was not just right as the gouge that was put in the clutch dog looks like it hit the forward gear in the wrong spot. Here's some pics of the damage. Any Ides as to what was going on or how to maybe fix it would be great. Specifically would water in the lower unit make the clutch dog not work right. Ideas as to how to find out where the water was coming from, and is the dog and gears shot. Someone mention trying to reshape them with a dremal tool could this work. Thanks.

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Forward gear

 

[64osby]

Re: Trying to rebuild 18 hp Johnson

cc, that really stinks.

I don't think a little water in there is the cause of the problem. Something else happened. I'm sure someone will let you know real quick

 

[HighTrim]

Re: Trying to rebuild 18 hp Johnson

That dog has had some abuse from poor shifting techniques from a previous owner. YOu have to really snap that shifter into gear quick, easing it in causes the damage you see.

I would personally look for a parts motor for a couple bucks with a blown powerhead or something. Buying the dog and gear seperate will get expensive for what you get. Im not sure about repairing that, that is better machining work than I am capable of. Maybe someone can chime in on that.

For sure need to reseal that gearcase though.

 

[Mas]

Re: Trying to rebuild 18 hp Johnson

Is it possible the shift linkage is not adjusted properly...not allowing the dog to fully engage causing wear just at the tips of the the dog and not allowing the dog to seat fully in the gear pocket?

Mas

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Is it possible the shift linkage is not adjusted properly...not allowing the dog to fully engage causing wear just at the tips of the the dog and not allowing the dog to seat fully in the gear pocket?

Mas

Is there a way to know for sure if the linkage is right. It seems it only works properly when the screw that goes thru the skeg is in place so the gears would have to be completely enclosed. and thus no way of actually seeing if the clutch dog is engaging properly. I guess I could try and mock something up to hold the linkage arm in place where it should be without the skeg on and be able to see the dog shifting.

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Also of note. The pics from the vary first page of this thread the first pics showing the motor. Is how the motor came to me IE In pieces. The PO clearly was looking at what all was wrong with this motor. After doing the reseal of the LU I noticed one day that the cradle was missing from this motor, and found it a little odd that that piece was missing. So someone had been in there , and removed it or it broke and was not replaced, And in that case they got in there and took out the pieces IDK. But tonight when i looked up the LU gears dog,and pinion. The only site I could find listing part numbers for 59 johnson 18hp was marine engines. and all the numbers they give when looked up anywhere where there are pictures. The gears do not match my gears. I have gears with 26 teeth all the pics from the part numbers listed on marinengines have 20-22 (Kinda hard to count on the pics), but it can clearly be seen there are less teeth on the pics then my gears. The flat spots at the peaks of the gear teeth is wider than mine(which is what drew my attention first and made me count). Is it possible the PO put a different set of LU gears in there. Losing or forgetting to put back the craddle in the process, and that be my problem with the linkage not working properly or whatever happened the wrong gears set for this motor. If need be I found a NOS forward gear and bushing for 16.50 NOS rev gear for 10.00 and a pinion NOS for 22.99. All These have the different teeth pattern would they work as long as i got all of them.

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Ok this is weird just found some gears at vintageoutboardparts.com. They have 3 gears listed under that part number 2 of them are like mine with 26 teeth. 1 is like all the others i found with 20 or so teeth. both listed under 377876 part number....?

 

[Mas]

Re: Trying to rebuild 18 hp Johnson

You probably found your problem. Work the propshaft manually with the the LU removed and skeg off. Slide the dog in and out of gear with the shift rod out of the way while turning the shaft...see how the gears engage with the dog and pinion.

Mas

 

[oldybutagoody]

Re: Trying to rebuild 18 hp Johnson

Forgive me if this has been asked and answered already because I haven't read the entire thread but the symptoms you were describing when you had the boat out on the water sounded to me like a spun prop? That clutch dog does look worn and if you had water in the lower unit you need to reseal it but you said the prop was spinning but not supplying power in both forward and reverse. If your problem is the clutch or shift linkage adjustment, the symptom would be power and then a "THUNK" as the clutch slipped out. Sounds to me more like the prop is spun. No?

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Forgive me if this has been asked and answered already because I haven't read the entire thread but the symptoms you were describing when you had the boat out on the water sounded to me like a spun prop? That clutch dog does look worn and if you had water in the lower unit you need to reseal it but you said the prop was spinning but not supplying power in both forward and reverse. If your problem is the clutch or shift linkage adjustment, the symptom would be power and then a "THUNK" as the clutch slipped out. Sounds to me more like the prop is spun. No?

That was the symptom exactlly when I gave it power there was a thunk then it would not go so if I'm understanding what your saying that sounds like a linkage or clutch problem... I've seen many threads were people where advised they had a spun prop and was wandering if that is my problem as well but looking at my prop I was not really thinking I could have a spun prop as it seems to be all mechinacaly driven pieces meaning something would have to break that would be clearlly seeable for it not to work. I assume I need a leason on spun pros to find out if this could be my problem. My prop shaft just hs a pin that runs thru it the prop engages that and then the cone shaped prop nut screws on and is secured with a cutter pin. To me it didn't seem like it could slip unless one of those pieces broke. But again I don't know so I'm probably wrong?

 

[oldybutagoody]

Re: Trying to rebuild 18 hp Johnson

My mistake Ccvolsdhf, I missed the part of your description where you described the "Thunk". It does sound like your clutch dog is slipping out of gear. A spun prop happens when the prop slips on its bushing. The prop is pressed on to the bushing. The bushing is the part that the drive pin engages. If the prop is "spun" bushing spins with the propeller shaft but the prop slips on the bushing. The symptom of a spun prop is usually good idle and low speed operation but lack of proper high end speed even though RPMs are high. It will also "surge" as it slips. The slipping clutch is accompanied by the "thunk" and then no power at all even with throttle. The way to diagnose a spun prop is to put a mark across the back of the prop and the prop bushing and run the engine (on the water), then check it, if the lines are no longer lined up. the prop has slipped. Obviously, that test can't be done with the lower unit apart as yours is now. Sorry to send you down the wrong path. I think your problem is the clutch and gears and you're in good hands with HighTrim and the other's advise.

That was the symptom exactlly when I gave it power there was a thunk then it would not go so if I'm understanding what your saying that sounds like a linkage or clutch problem... I've seen many threads were people where advised they had a spun prop and was wandering if that is my problem as well but looking at my prop I was not really thinking I could have a spun prop as it seems to be all mechinacaly driven pieces meaning something would have to break that would be clearlly seeable for it not to work. I assume I need a leason on spun pros to find out if this could be my problem. My prop shaft just hs a pin that runs thru it the prop engages that and then the cone shaped prop nut screws on and is secured with a cutter pin. To me it didn't seem like it could slip unless one of those pieces broke. But again I don't know so I'm probably wrong?

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Cool thanks .... so anyone have any idea why I've found 2 different sets of gears with the same part numbers...as stated my gears have 26 teeth on them most of the replacements i' ve found are a larger gear having 20 or so teeth on them both listed under the same part number. I don't know which ones are at marineengines as there is no picture. I've found plenty that are ONS pretty cheap but there are the larger ones with less teeth would it be ok to get a set of these and change them out with mine? Frd,rev,and pinion. I believe the clutch dog is the same for either gears

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Bump.

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Got a question my gears have 26 teeth on them most of the replacements i' ve found are a diffrent gear having 20 or so teeth on them both listed under the same part number. I don't know which ones are at marineengines as there is no picture. I've found plenty that are ONS pretty cheap but there are the larger ones with less teeth would it be ok to get a set of these and change them out with mine? Frd,rev,and pinion. I believe the clutch dog is the same for either gears. All these gears are on ebay so I'd like to go ahead and order them ,but don't know if the gears with less teeth, but the same part number would work?