What is knob for?

[Harker]

I have either a 92-94 30 hp or 95-96 35 hp 2 stroke, 2 cyl Johnson. On the lower front there is a primer knob and a knob off to the right that goes into an aluminium solonoid type thing with about 5 hoses coming out of it..it's hard to pull the knob out and doesn't seem to make a difference on how the motor runs...I have bought two manuals and neither shows this part...PLEASE HELP!!! Thanks, Lee

 

[The Marine Doctor]

Re: What is knob for?

Just to guess...it sounds like a primer of some kind.<br /><br />Are there any of the hoses hooked up to fuel?<br /><br />TMD

 

[rodbolt]

Re: What is knob for?

hello<br /> it sounds like you somehow have a ex navy seal motor.<br /> we modified some like that to drain water from the block,cylinders carb and fuel system after a submarine launch. if it is a ex navy motor there are also some other mods such as 1/2 inch flats milled on the piston skirts from the wrist pin area down to the skirts.<br />if you can post some pictures of it. <br /> good luck and keep posting

 

[Harker]

Re: What is knob for?

The hoses go all over the motor and one goes out the bottom and isn't hooked to anything. I think maybe the Navy Seal thing is correct as these were millitary motors. Here is a website url to see one, hope it doesn't violate the spam rule, I'm not selling, I bought one and am trying to find out about it. Thanks tons..Lee<br /><br /> http://www.smalloutboards.com/j30ljet.htm

 

[Mike6158]

Re: What is knob for?

I have a similar motor. The previous owner said that it was a Navy Seal issue motor and like the previous poster said it's for draining the fuel system and cylinders after the motor has been submersed. He also said not to jack "with that little knob"

 

[Harker]

Re: What is knob for?

Heh heh heh...so....do you leave it pushed IN or pulled OUT? Does yours smoke a lot at low speed? Does it get terrible mileage? Did you ever find a correct manual for it?

 

[rodbolt]

Re: What is knob for?

hello<br /> most of these motors had very short life spans as they were all custom built. call Ron at Rons marine in portsmouth virginia. he and robert rebuild a lot of these motors as well as the 55 omc p250 omc pump motors. one of the first unmods is to eliminate the machined pistons. with a 1/2 inch wide slot cut in them they dont last long or seal well. but they were designed to be sub launched and left on the beach. good luck and keep me posted

 

[Harker]

Re: What is knob for?

Bet those piston Mod's are what makes it smoke a lot. I'll probably just run it as is and maybe put new pistons in it when compression falls off. It starts first or second pull and idles well(but smokes like h***) Would one of the mods have been opening two holes in the exaust tube to exit over the lower pivot?

 

[Mike6158]

Re: What is knob for?

The little knob stays pushed in. The motor starts on the first pull... sometimes second and it runs pretty well. Yep... It smokes a lot plus it's always spitting a little fuel out of a hose on the throttle cable side of the engine. The previous owner (who so far has been trustworthy) said that it's normal. He also said that it's a plug eater. Maybe all two strokes are? I don't know. <br /><br />My solution to the smoking spitting problem is simple I'm going to replace the motor sometime within a year. Maybe even go to one of the small 4 strokes.

 

[Mike6158]

Re: What is knob for?

Update- Well.. my little 35HP motor had a very short life span. I think that the water pump went out. It died this spring while I was zipping across Matagorda's East Bay. I wonder if I could rebuild it myself or if it is even worth it? I replaced it with a 25HP 4-stroke Yammyjammer but I can't help but wonder about overhauling the old OMC. I've never had a boat motor apart but I've rebuilt a few car engines (I know, not the same thing or even close)

 

[Paul Moir]

Re: What is knob for?

That's too bad. If you want to see what rebuilding an outboard engine is all about, check out the post 'Sticky Rings' a little ways down. <br /><br /> Better yet, here's a link.<br /><br />Begin by pulling the head to inspect the damage. Who knows, mabey you're lucky and you just blew the head gasket with the overheat?

 

[Mike6158]

Re: What is knob for?

Great. Thanks for the link. I wonder if there is anything about the military version of this motor that might make it cost prohibitive to overhaul. I've heard that they are disposable. Ie the Navy Seals basicly use it to get to shore, kill the enemy, bring it back to the sub, and then sink it.<br /><br />The motor pulls easily by the way. It just won't start (like it has little or no compression)

 

[Harker]

Re: What is knob for?

Mike, mine quit last week on me..I'm thinking it was the gas pickup in the tank. The primer hose was leaking and the top nipple where the prime shoots into the motor was plugged. I rebuilt the carb, sealed the holes that exaust was coming out of over the lower bracket, and it seems to run better (different fueltank). The low speed adjustable jet was set 4 turns out from lightly seated. I picked up a complete gasket set for the powerhead and am going to knock it down this winter..I also have a spare pumpjet lower unit and looking at it..think that I can modify it back to a prop real easy.I also figured out the stop switch dillema I had and installed an on/off toggle switch to work. Dinking with this motor has been a real education and now I am not afraid to tackle anything on it. Good luck with yours..I hope it's salvageable.

 

[Mike6158]

Re: What is knob for?

I hope that it's salvageable too. It was running like a top when it quit. Have you tried to take the cylinder pump "thing" off? If I can rebuild the motor I would like to remove that thing so fuel doesn't drip into the water when it's running. Mine is prop drive. If the motor is crap you might be able to do something with my lower unit???? Something to consider. I hate seeing potentially good equipment go to waste.

 

[Harker]

Re: What is knob for?

I haven't tried taking the "dewatering" device off yet, but I will when I take the motor down this winter. I want to plug all the orfices that those hoses go to so I don't end up with an airleak in the crank case. Mine stopped at full throttle and then wouldn't start except for a few revolutions when I hit the primer..then I took the cowl off and saw that the primer hose that goes to the top of the carb sprayed a little when I tried priming it and a little gas sprayed out of the hose where it hooks to the primer..I cut the ends of the hose back, found a gallon of gas on the walk back around the lake from where I drifted ( why is it you always drift to the wrong side of the lake?) and got it running just enough to get back to the dock. After rebuilding the carb it runs great. Have you checked for spark and fuel?

 

[Mike6158]

Re: What is knob for?

No.. The motor was smoking and very hot. Hotter than normal. When I tried to crank it it felt loose. I tried to crank it for 5 hours in between fishing, taking fish off, and calling people for help

 

[Mike6158]

Re: What is knob for?

Harker- Did you ever find a good manual for your motor? If you did does it have "how-to" overhaul information in it?<br /><br />Mine is a model AM35D. According to a site that Trent from iboats recomended to me ( http://web.archive.org/web/20020210100606/www.evinrude.com/docktalk/modref/others/mtary.html ), it was built in 1995/96 and is the 35HP version.

 

[Harker]

Re: What is knob for?

Mike, I got a factory manual for 9.9-30 hp 2 cyl johnson evinrude motors p/n 507122 and a parts catalog for 20-35 rope models..both have 1996 dates on them. These motors have some differences compared to the ones in the manual..mine has what looks to be a 25hp carb and the cd2 pack is a different number. Mine acted up again today..buzzing along and it died down and almost stopped, I hit the primer and it kept it from quitting so I idled back to the dock..almost like a S.L.O.W deal with the temp thingy..I could lay my hand on the head for as long as I wanted so I don't think that is the problem. Checked the plugs and they looked ok..the threaded deal for the throttle cable that adjusts with two nuts on the sides of a bracket broke so I have to get a new one.It seems my problems started when I plugged the two holes that exaust was coming out over the lower swivel bracket on the transom mount. I'm waiting for a carb kit and waterpump kit for my 25 Mariner and as soon as I get them installed I'm switching motors and gonna start tearing down the johnson..but first I have to carve about 20 more duck decoys before season starts.

 

[Mike6158]

Re: What is knob for?

Dang.. if I wasn't thinking about rebuilding my old Johnson I could fix you up. I've got a fairly new Teleflex (used like 2 times? and not a cheapo throttle console) throttle / shifter assembly for my old Johnson. It's just laying around the barn. It has all of the cables and motor brackets including the one that I think that you need. I bought it right before the motor crapped out.<br /><br />On the other hand, I know what my world spins like. It could be months or years before I get to fixing the motor (if it can even be fixed).<br /><br />If you want it, I'll make you a heck of a deal on it.<br /><br />I ordered a manual from iBoats. Where did you get yours?

 

[Harker]

Re: What is knob for?

Mike, I'm thinking it was "Master Tech"..my old computer crapped out and I lost my bookmarks. This guy sells factory manuals and was really helpful when I called. He went and actually looked at the manual and then suggested the parts catalog too since it showed the parts schematics and numbers. I had the Seloc and Chilton and they are a step above worthless in my opinion..too general and hard to follow for specific engines. Mine is a tiller model,is your Teleflex for a remote?