'74 Merc 115HP Rotor.

12Footer

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Mar 25, 2001
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8,217
I don't have the book yet,but it is on the way. In the meantime, I think I have found the problem to be the rotor inside the distributor . It turns freely,with just one finger.<br />My question is, how is this rotor attached to the shaft? Should it turn free like that?<br />My brother in-law's boat,he has the book,but forgot it.It will be week or so before I can get it (he lives 60 miles away).<br />Any tips on how to remove this rotor,and anything else pretaining to this beautiful beasty would be greatly appreciated.
 

corm

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May 12, 2000
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1,241
Re: '74 Merc 115HP Rotor.

Hey Big 12,<br />Unfortunely the rotor is cast on to the shaft making it one piece .(they are spendy)<br />You have to take the dist off to remove it.<br />It is easy, but envolved. Lots of parts removal to get to it. The rotors can look rather bad and still work ok,unless they are<br />broke.<br />...have fun...corm
 

kevlar3000

Petty Officer 2nd Class
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Mar 20, 2001
Messages
194
Re: '74 Merc 115HP Rotor.

I don't think it should be turning free, the are attached to the shaft. I hope it is not a big prob... I have been told they are a pain to replace.
 

corm

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May 12, 2000
Messages
1,241
Re: '74 Merc 115HP Rotor.

Missed the turn free part of your post 12.<br />Check the timming belt it may be broke.<br />If it isn't then you'll need a new rotor.<br />As it is cast on to the shaft.<br />...have fun...corm
 

12Footer

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Re: '74 Merc 115HP Rotor.

Thanks for the replies on this, Corm and Kevlar.<br />The timing belt is intact, but I ordered a new one today,as it is getting ready to go.<br />The problem is where the rotor is attached to the shaft. I can spin it by hand,but there is no bolt or retaining clip holding it on.Like you said, it appears to be broken at the rotor. But it doesn't appear possable to seperate the two (shaft from rotor.. It sure looks like a chore,but have put a plastic bag over the beast until he delivers that manual
smile.gif
<br />This boat hauls buggy when it's runnin, but looks like a beached floating dock when it's down.
 

kevlar3000

Petty Officer 2nd Class
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Mar 20, 2001
Messages
194
Re: '74 Merc 115HP Rotor.

Why they made those with non removable rotors... The whole thing has to come out, the whole !!$@@&**&!!! thing. My mechanic asked me how much I thought a tune up with cap and rotor would run for an inline w/a distributor. I knew it was a bunch, but not 600.00!!!! lol, my *** .<br /><br />Good luck!!
 

12Footer

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Re: '74 Merc 115HP Rotor.

UPDATE.. It is all back together. I found the rotor/dist assembly locally for 10bucks.<br />It was in terible shape,tho. It seems Merc wrenches like this sealant that turns into goo. This goo is used (maybee at factory?) to provide additional sealing of the dist cap.<br />I am pretty sure it is factory goo, as it was on all 10 part motors at the shop, and the one in my driveway. Anyhoo, this goo ran-down the dist assy, and into the dist cap,got all over the metal trigger ring, and pickup. This is probably what stripped-out the old one ??!!!<br />This goo made it hard to turn. I have found NOTHING on the PLANNET that desolves this stuff!!<br />WD40,carb cleaner, nothing. But the WD40 DID free it up enough to get the replacement dist shaft to rotate.<br /><br />Since I replaced the entire assembly, all my paint marks to allign the thing with are gone,so it's "best guess" on the timing for now. The timing belt was cracked, so I had to purchase a new belt. The chjeapest place had it for 20buks, and had to be mail-order.I opted for a local marina, and got the thing for 35 buks. But no wait.<br />I'm about ready to fire it up (Note, crossed-fingers") later today,after my other bro-in-law gets his truck over here for wiring trailer job.<br />I'll post the results of the "key twisting" when I get done with that.
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: '74 Merc 115HP Rotor.

UPDATE.. It is all back together. I found the rotor/dist assembly locally for 10bucks.<br />It was in terible shape,tho. It seems Merc wrenches like this sealant that turns into goo. This goo is used (maybee at factory?) to provide additional sealing of the dist cap.<br />I am pretty sure it is factory goo, as it was on all 10 part motors at the shop, and the one in my driveway. Anyhoo, this goo ran-down the dist assy, and into the dist cap,got all over the metal trigger ring, and pickup. This is probably what stripped-out the old one ??!!!<br />This goo made it hard to turn. I have found NOTHING on the PLANNET that desolves this stuff!!<br />WD40,carb cleaner, nothing. But the WD40 DID free it up enough to get the replacement dist shaft to rotate.<br /><br />Since I replaced the entire assembly, all my paint marks to allign the thing with are gone,so it's "best guess" on the timing for now. The timing belt was cracked, so I had to purchase a new belt. The chjeapest place had it for 20buks, and had to be mail-order.I opted for a local marina, and got the thing for 35 buks. But no wait.<br />I'm about ready to fire it up (Note, crossed-fingers") later today,after my other bro-in-law gets his truck over here for wiring trailer job.<br />I'll post the results of the "key twisting" when I get done with that.
 

kevlar3000

Petty Officer 2nd Class
Joined
Mar 20, 2001
Messages
194
Re: '74 Merc 115HP Rotor.

Good Luck!! I hope it works well for you!! Itis hard to do better than 10 bucks! :D
 
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