any harm in back flushing ’67 Johnson 100 hp?

[frankr]

Yeah, the plunger is supposed to be free in the vernatherm. And yeah, they do drink fuel. I sold mine because I couldn’t carry enough gas to go where I wanted to go. 6-8 GPH is the norm. And yeah, I did exactly what you did—removed a Merc with rear steering bar and replaced it with an OMC with front steering. The customer drove it all the way home, then called me to say it was backwards. Holy crap! I told him not to run it and I would come down and fix it. He said, naw he likes it that way. Needless to say I went down and fixed it anyway. Have you discovered that if it is a rack & pinion steering helm you flip the rack from top to bottom (or is it bottom to top?)

I highly respect fleetwin’s opinion, but I think 50:1 is just fine. Think about it, with all the fuel you are dumping through that engine, how could it possibly not get enough oil?

[Steve A W]

Can You post pictures? I like those old Lone Stars.

Steve A W

Member of the MOB chapter.
I live in Northwest Indiana

[boatman]

Frank and fileetwin,

This is an old teleflex drum system. I am guessing I unbolt the drum from the shaft and flip it over to make it steer correctly. Took my heart rate a couple minutes to get back to normal after I almost ended up on the rocks. Will have to experiment with trying different holes for the motor trim. Was running it on the middle hole, seemed to plane well. Also, will take a look at the pitch of the prop. Tops out in the low 30’s. Thought maybe I’d get a little more speed running 100 hp on an 800 lb hull. Ran the oil at about 40:1. Runs well at speed, idle needs a little work. Is there a low speed jet on this motor or is the only adjustment the slider bar on the port side of carb?

I have 6 boats from the late ’50s-early 60s that I am redoing. Really had fun with this Lone Star pocket cruiser on the water for the first time. Yesterday was 70’s, rest of the week is cold. Hope to get at least one cruise on the Chicago river through the downtown skyscrapers with my wife and kids before It goes into storage.

Steve, if I can figure out how to post pics I’ll put a couple up.

Paul

[fleetwin]

quote FrankR:

Yeah, the plunger is supposed to be free in the vernatherm. And yeah, they do drink fuel. I sold mine because I couldn’t carry enough gas to go where I wanted to go. 6-8 GPH is the norm. And yeah, I did exactly what you did—removed a Merc with rear steering bar and replaced it with an OMC with front steering. The customer drove it all the way home, then called me to say it was backwards. Holy crap! I told him not to run it and I would come down and fix it. He said, naw he likes it that way. Needless to say I went down and fixed it anyway. Have you discovered that if it is a rack & pinion steering helm you flip the rack from top to bottom (or is it bottom to top?)

I highly respect fleetwin’s opinion, but I think 50:1 is just fine. Think about it, with all the fuel you are dumping through that engine, how could it possibly not get enough oil?

Yeah, Frank is right, was just thinking the extra oil might be a little added insurance to keep this thing humming along.
But, now that we have Frank’s attention, I want to make sure I did not mislead you about getting that gearcase off.
Boatman was going to do a water pump job, but very wisely just pushed the gearcase back up into place when it wouldn’t come down much more than an inch or so.
I explained that the shift harness had to be disconnected, and consulted a service manual that confirmed that the gearcase and extension housing must come down as an assembly. Boatman still couldn’t get the gearcase down even with the extension housing released along with the shift harness, he wisely just reinstalled the gearcase, we both are assuming that the shift harness has swelled/corroded into the exhaust housing where it enters into the lower pan of the engine.
I have always wondered about the access cover on the extension housing: #96:
http://www.marineengine.com/parts/johns … case+Group
What purpose does this access cover serve, did I miss something in the manual, it was kind of vague.
Again, we are both assuming the shift harness has swelled/corroded into the exhaust housing. Boatman decided he would pull the powerhead in the winter to get better access to the shift harness so it could be gently coerced out of the exhaust housing without damaging it.
Frank: please let me/us know if I have missed something when it comes to removing this gearcase.
Thanks
Don

[frankr]

I didn’t say anything about that, because I honestly can’t remember. I do know that on the 75-90hp V-4 motors, the electric shift cable came through the plate that you used to remove to access the manual shift rod connector. But it appears from the manual that is not the case with the 100hp. So, without being there to put my eyeballs on it, I just don’t know. Sorry ’bout that.

As for the Teleflex helm, if you have the one I’m thinking of, you just swap the cable and spent tube (plastic tube that covers the greasy end of the cable that moves in and out as you steer.)

[Author]

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