1974 Chrysler 105

[Fasthead]

I just got a boat in nice shape given to me, it has not been used/run in at least 12 years. Going over it yesterday i found gear oil leaking from the lower unit. I am ordering a seal kit. Is there anything else i should replace while I'm in there? Water pump(impeller) and gasket? Ordered parts manual but it hasn't gotten here yet. Anyone know which gasket I need?
Thank you all in advance.

 

[Frank Acampora]

Re: 1974 Chrysler 105

Always replace the impeller. There is no gasket. Order a fuel pump diaphragm and gasket. Once you have replaced them, then there is almost nothing to do. Check compression ratio before doing anything else. It will tell you if it is worth doing any maintenance.

I don't remember if the 1974 105 had points or not. If there is only one wire coming from the distributor, it is points. Clean them and re-gap to .010.

Then go to the sticky at the top ofthe forum and use the instructions to synchronize timing and carbs.

With an engine of unknown history, assume that anything that can be out of adjustment is and set everything back to specs.

Oh yeah--forgot--there is a gasket under the stainless plate. You can make one out of grey 1/32 gasket paper available in auto stores.

 

[emoney]

Re: 1974 Chrysler 105

Probably should stop by the closest marine dealer and pick up some lower unit drain/fill plug gaskets, if you didn't order them with the LU seals. I'd replace the nuts on the LU bolts too. "Sitting" is the enemy of outboards so assume the worst and hope for the best. Let us know how it goes.

 

[jerryjerry05]

Re: 1974 Chrysler 105

You sure it's oil from the lower unit?
Older outboards ,drip unburned gas/oil and it looks like gear oil.

Drain the lower unit,pressure test.
You might be doing unnecessary work??

Pics.
Fill out the profile,location?
You might be close to someone who can help??

 

[Fasthead]

Re: 1974 Chrysler 105

Thanks all for the replies.
I'm sure it's gear lube, can't mistake that smell. Plus there's been no gas in this boat for 12 years. It was in my friends family in a garage since 2000. I was just going over it and making my list lowered engine and lube started leaking from a weep hole. Will start w/ compression, i know the boat/engine was taken good care of but it has been sitting a long time.
The boat 1974 MFG 16' Caprice is in great shape, no rot/cracks/abuse. Wash and wax and good to go. Plus it was my favorite price.
Thanks again

 

[Fasthead]

Re: 1974 Chrysler 105


Here's what I've got going on.

 

[Frank Acampora]

Re: 1974 Chrysler 105



lower unit lube can leak out that weep hole if the top seal is failing. Do not mistake this for the top seal of the water pump. They are two different things.

To replace it (PIA) you must remove the pump, impeller, and stainless bottom plate.. The seal is down in the hole below the water pump. Most times I have replaced them, I already had the lower unit disassembled so a good couple of pulls upward on the drive shaft would take it out along with the top roller bearing. Removuing it without removing the shaft is way more difficult, but still do-able.

 

[Fasthead]

Re: 1974 Chrysler 105

Just tested compression, by hand. I've got about 45psi on all 4 cyl.
I removed plugs and turned over by hand first, squirted some oil in first. Turned easy enough so I threaded compression tester opened throttle and turned over. 1 stroke through gave me about 45psi. Service manual says 140 psi warm. I am guessing that is batt hooked up starter turning over engine a few strokes compression builds and holds? I've never worked on a 2 stroke. Any help/advice is greatly appreciated. Thanks so far and for future.

 

[Frank Acampora]

Re: 1974 Chrysler 105

You can NOT check compression turning by hand.

Sometimes, (when buying an unknown engine) as a rough guestimate of engine condition I will hold my thumb over the plug hole and turn the crank. If it blows my thumb off the hole, then compression is probably good and a rebuild is probably not needed. Usually, these engines will either have good compression or none.

If you observed 45 PSI while turning by hand, the chances are good that compression ratio will be within normal limits when cranking.

Because a 2 cycle engine has side ports in the cylinder, every time the piston moves down to bottom dead center the cylinder goes to atmospheric pressure. Thus, throttle position is not important for compression testing. ---Oh, OK! For the purists out there: True, a closed throttle will make the engine crank very slightly slower, but not enough to make any difference in the readings.

Even though the cylinder does go to atmospheric or almost there, PSI will build for about three to four revolutions then level at final reading.

 

[Fasthead]

Re: 1974 Chrysler 105

So I should do the fuel pump and a tune up? See if it fires.
All goes well I'll do all the seals in the drive and water pump.
Anybody see anything wrong with my un2stroke educated plan?
Thanks