Lower Unit Modification? (1971 Chrysler 55hp)

[wildartstech]

Just picked up a 1971 Chrysler 55hp outboard (557HC). I got it for free and was told it ran before it sat for the last 5 years. After inspecting it has some small issues. Mice built a nest in the lower cylinder, chewed away on one of the plug wires and the wire for the electric choke looks shot. So to my questions.

1. The motor is too long for my transom. It sits about 5-6" (+-) too low or so. I noticed that the lower unit of the motor is bolted into what looks like an extension on the main shaft. I couldn't help but wonder that... Chrysler probably built the motor to have 2 different lengths one for shorter transoms like my boat and another like my engine built for slighter longer transoms. Hence the question, can this section be removed and the length of the motor shortened to fit my boat? If so does it need a new shaft or does it require additional parts, or how big of a pain is it to do? Keep in mind if shortened in this way the motor would fit my transom length almost perfectly.

2. The electric choke wire is a wire wrapped in wire (?). Can it be replaced with a regular electrical wire or do I need the special wrapped wire? Should I order it off of iboats? is there a cheaper/easier replacement?


This is a photo of the engine with the section circled.

 

[wickware]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

1. Info has been posted on the long vs short leg but I c/n guess what a good search would be. I feel the info will come back soon or info on what to search.

2. The chokes wire is standard wire vs braided on my 1970 35 hp Chrysler (attached).

 

[wildartstech]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

Yeah, I answered probably a dozen of my questions searching iboats but gave up on the lower unit shorting length cause I exhausted my ideas on what to search for... Thanks for the photo. At first it looked like the electric choke wire was chewed up by the mice but on closer inspection it is some weird wire maybe that's all someone had laying around or something. Wouldn't be surprised if it still worked but why go through the pain of not replacing something so simple that's soon to go.

 

[wildartstech]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

Also, anyone have a parts list/diagram? I could answer my own question with one of those...

 

[wickware]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

Try sending a PM OR Hello Frank Acampora! Related to long/short Chrysler LU legs info (link). I?m almost sure the explanations I read were from him.

PS. I have not sent a PM (privare message).

 

[Frank Acampora]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

You can unbolt the 5 inch extension and inside there is a 5 inch brass tube extension you can simply slip off. (HaHa!-maybe! Lots of penetrant and a good grab with a pliers, twisting) Your 35 lower unit should bolt right up since in the early years, the 35, 45, and 55 had the same gear ratio and drive shafts. If not, you will need to find a short shaft drive shaft. No real fuss: After you remove the water pump the long shaft will slip right out and the short shaft will slip in. The pinion is splined but there is no nut on the end of the shaft.

 

[wildartstech]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

Thanks you! I figure I should check the water pump anyways before I try to start the motor. Also have to get the exhaust port cover off the side of the cylinder. The bolts are frozen on there even though the engine looks pretty clean. Part of the Mouse nest is still stuck in there. From the bottom cylinder I can still see pieces of plastic bag, twigs & part of the spark plug wire insulation chewed and neatly nested in there.

 

[wildartstech]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

I guess now I'm looking for a short drive shaft. The one I have now measures at almost exactly 31.5" Since the extension housing is almost exactly 5" I would guesstimate that the replacement shaft I am looking for it probably right around 26.5" or so? Any ideas where I can pick one up? It's either that or a jackplate of sorts...

 

[wildartstech]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

BTW! THe squirrels built a nest all the way from the exhaust right next to the prop up into the lower cylinder. I had a hand full of acorns and a a bucket of fuzzy grassy stuff after removing the lower unit and cleaning everything out. But ironically for a free motor that is literally all that was wrong besides 2 chewed off wires. I'm thinking I can get this thing turned over in few more hours of work. Now to find a shorter drive shaft.

 

[wickware]

Re: Lower Unit Modification? (1971 Chrysler 55hp)

Franz has over 30 years of accumulated parts and experience. He is a factory certified
Force technician and is a member of the Kansas City Marine Dealers Association
and the Marine Retailers Association of America.


Hours: Monday- Friday 10-6 (Central Time)
With Extended Summer Hours!

E-mail us: FranzMarine@aol.com

Franz's Marine Service
Franz Buddenberg
(816) 966-8085
12608 3rd Street, Grandview, MO 64030