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1957 35hp Big Twin Shift Problem

H

HowardJ

New member
Hi, I cannot get my motor to shift between forward and reverse. I can get one or the other by adjusting the screw adjustment on the side of the cowling, but not both. When I try to find a happy medium, the motor bucks and revs when in forward and under power on the water. It appears to shift ok when I test it out of the water using a garden hose to supply water to the inlet, but when I get it under power in the water I cannot find an adjustment point that lets me get both forward and reverse without that bucking and revving. I really want to figure this out before I tear up my gears. Any advice will be greatly appreciated.
 
You have worn out linkage below the powerhead. To prove it, remove the oval access plate on side of midsection and you will see the shift rod inside, Try moving that shift rod up and down with shifter in neutral Any significant movement represents wear. 1/4" movement represents a LOT of wear. Powerhead has to come off to evaluate and replace worn parts. I don't mean to discourage you, but don't be surprised if the clutch dog and gears are already damaged. That stuff didn't get worn out overnight.
 
Hi fdrgator, thanks for the quick response. In neutral, I do indeed see that 1/4" of slop. So, I will start opening things up to find out where the wear is, and what needs to be replaced. This is a good time for this. I live in Fresno, CA and it is too doggone hot for any good fishing here now anyway. As far as discouragement, not an issue. My boat and motor are over 60 years old, like me. Some days I am a fisherman, some days I am a boat/motor mechanic. Some days, a little of both! All good.
 
Those motor are well built.----Mostly metal with no plastic junk to speak of.-----Don't give up on it.----Most repairs are straight forward.-----Parts are easy to find in my opinion.
 
I removed the powerhead and the gearcase. I found two areas of concern. First, the plastic bushing on the shift handle appears to be pretty badly worn. I have found a replacement, and we will see if that fixes that area. Second, one of the screws on the connector block between the upper and lower shift rods was loose. After I tightened that up, there does not appear to be any slack in the assembly from the shift cradle in the gearcase up to the top of the shift rod assembly. Once I get that bushing, I will reassemble and test.
 
Good news, I got it back together and the shifter mechanism seems to work fine. Bad news, no water coming out of the exhaust! Pulled the lower unit back off and opened up the water pump. 3 broken vanes. I think it just got old and dried out since I have not had the boat on the lake all year. I had a spare impeller, put in a new Woodruff key, and re-assembled. Will driveway test again tomorrow.
To fdrgator, big Thank You to you, sir. I greatly appreciate you sharing your knowledge. I have owned and operated this motor for over 10 years now, and had to do a lot of repair work initially to get her running. I am proud to say that I have not yet had to take it to a mechanic, but I humbly acknowledge that this is due in large part to kind and generous people like you who coach those who are willing to learn. Again, Thank You!
 
racerone, I agree! I have enjoyed learning about this motor. I was an engineer for 35 years, and I love working on a piece of well-designed and stoutly-built machinery. I sympathize with her when she has issues...I am getting old, too!
 
Great thread....welcome to the forum, Howard. You are in good hands. Working with Racer and Gator, you have easily 130 years of premium professional experience. If Joe Reeves chimes in....you got 200 years between the 3 of them, but Joe is primarily retired. Probably doing a little traveling these days.
 
I finally had a chance to get the old girl out on the lake and she ran great! No more shift issue :) Thanks again to fdrgator and racerone for all the direction and support. You guys are great.
 
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