1977 65hp chrysler prop

[Devildog836]

I have a 65hp 1977 outboard and need a new prop. Are they interchangeable with newer props or am I out of luck since I can't find any for that year and HP? I spun my prop and don't have a press to fix it myself

 

[Sea Rider]

Welcome to Iboats,

If can't fin one, send prop to a prop shop and have it repaired, it's not only pressed, it's heat vulcanized too...

Happy Boating

 

[Devildog836]

Thanks. That's what I'll do

 

[jimmbo]

FWIW. I don't think there was a 65 hp until 1978

edit: I was mistaken, Michigan catalog does show a 65 in 1977

 

[Devildog836]

Found one on eBay hope it works. Now another question. The new prop slides a tiny bit forward on the shaft after it's been tightened down. I don't remember if the old one did too. Is this an issue?

 

[NYBo]

Is the thrust washer in place?

 

[Devildog836]

No washers at all.

 

[Sea Rider]

All props needs a thrust washer unless comes factory fitted casted with washer, if not prop at speed will push forward and literally abrade prop housing along front prop body, check, very bad music indeed.



Now has a Over/Through Hub Exhaust Prop which didn't know existed...

Happy Boating

 

[Devildog836]

Thanks. To eBay I go again

 

[Devildog836]

I've been searching the web for a thrust washer that would fit my boat with no luck. Went to the local shops and they wouldn't even look at it because it's too old. Does anyone have a spare they wouldn't mind selling?

 

[jimmbo]

All props needs a thrust washer unless comes factory fitted casted with washer, if not prop at speed will push forward and literally abrade prop housing along front prop body, check, very bad music indeed.


Happy Boating

That is not true. Any OMC and Chrysler engines that used a drive pin did not have a thrust washer in front of the prop. The props thrust was transferred entirely through the drive pin. On OMC pin props there was often a washer between the pin and the prop, but it normally was free to spin and move. It was there to prevent the prop from sliding backward in case the rubber hub failed, which then, because of a lip on the prop would trap the drive pin and make it impossible to remove the prop without cutting and chiseling. Half the time that washer was lost and never reinstalled. Most people didn't know it existed or why

A lot of Chrysler engines had splined props and propshafts, but still used a drive pin to locate the prop and provide thrust transfer. The pins were Stainless steel and were not Shear Pins.

 

[Texasmark]

Yes sir on the drive pin installation, we called them shear pins because that's what they did. No washer up front.

The front of the hub's brass insert (part of the otherwise rubber hub pressed into the alum/bronze prop casting) had a detent into which the drive pin rested. Yes there was a little slop. No you don't want a lot as you don't want the pin to slip out of the slots in the front of the prop. Course when going forward, the thrust of the prop keeps the pin in the slot in the prop hub.

Current props with no shear pin but a splined shaft are put on tight. On my 2002 90 hp Merc it was torqued to 55 ft lbs and the nut pushed it up against a tapered (to match the taper of the prop shaft) washer to (as Sea Rider said) keep the prop from moving up into the LU outer casting and eating it and the prop up. The interface was tapered to ensure centering of the washer to reduce vibration and ensure an even mating surface.

 

[jimmbo]

I have never seen a Stainless Steel Drive Pin shear on any of our OMC, 35, 40, and 90hp engines. Knocked 2 blades off one prop and the pin held. I guess some aftermarket pins might have been soft steel or brass and they would shear, but the OMC pins were SS

 

[Texasmark]

I have never seen a Stainless Steel Drive Pin shear on any of our OMC, 35, 40, and 90hp engines. Knocked 2 blades off one prop and the pin held. I guess some aftermarket pins might have been soft steel or brass and they would shear, but the OMC pins were SS

Well sir, they were made of brass when I used them back in the day when a Johnson 25 running off a 6 gallon pressurized tank of gas at 24:1 (30 wt. motor oil) mix because Ole didn't figure it needed a fuel pump, was king of the seas. Don't know about the larger engines in later day designs.

Those chose to shear at the most inopportune times, like when you were on the windward (awind) side if rip rap where the fish liked to feed and you had to have your engine ready to save your boat from the rocks and just when you needed it most.........bam!!!!!!!!! I left OMC and went to Merc for that reason. I had a 10 hp Scott Attwater that had a bail-a-matic for bailing your boat...which always leaked back then or water came in over the gunwales, that had a little rubber doo-dad on the tiller handle bracket with 2 brass pins and 2 SS cotter keys for your convenience when, not if, the problem arose.

So sir, with what you said, maybe that's why they are referred to as "drive" pins today rather than "shear" pins of my day. Grin

 

[Devildog836]

Thanks everyone for the help and advice. I appreciate it