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1972 50hp merc

W

willstox

Contributing Member
"Hey guy's, I just picked

"Hey guy's, I just picked out a older merc, 50 hp, the s# 3349495, it has "Thunderbolt Ignition" on the cover as well as 4 carbs on it. Can anyone give me any information about this? I know before I try to get it running I will have to rebuild the carbs...it's been sitting for 4 years, I hope someone can give me alittle.....or alot of information. Thank you all for the help."
 
"Hey, your engine is a 1972 me

"Hey, your engine is a 1972 mercury. Make SURE you do a compression test and spark test before attempting any repair on your engine. Always start with the basics.Those engines are alright when running, but they can very quickly become a nightmare when they dont run. (i.e) problem after problem. They also had reverse problems.One more thing, if it does end up needing just the carburetors cleaned, those are one of the worst carburetors to remove and clean, in my opinion. If you end up doing that, you'll see what i mean, but it can and has been done by many people lol. I dont want to be to negative but i really dont like those engines personally, there might be people on here that love them? Well thats my opinion, i hope everything works out well for you and you have a great boating career.
Goodluck!"
 
A 72 -50hp with 4 carburetors?

A 72 -50hp with 4 carburetors???? Hold on to it as it must be a racing model.
 
I question the 4 carb thing my

I question the 4 carb thing myself...i owned a new 69 and a new 1973 50 merc and they were 2 carb models..after accepting the fact that it may be a racing model i will say 2 things..i doubt if the wiring is still in good shape..inspect that and make a decision..new harness will cost a bit if you can find one..the 2nd thing is that i would suspect that you got a real gas hog if it is in fact a racing model..the 2 carb 50 used more gas on a lighter boat than the evinrude model 88 that i am running now......if you do have to pull the carbs make sure the linkage is adjusted correctly when you replace them(that they operate each carb in syncro) or you will burn a piston..the standard lower unit on that particular mercury wasnt the best in the world either...it may be fun to rebuild but i would not spend a lot of money on that motor...
 
"Sorry guy's, I ment to sa

"Sorry guy's, I ment to say it has 4 cylinders, NOT 4 carb's..............lordy !!! I have no fire from my coil, I pulled the coil wier and got no fire....where to start at? It has a few wier's that are in need of replaceing as well........what would be the best repair manule to buy?"
 
William..cant help you on book

William..cant help you on books...i think mine went with motor when i gave away...maybe someone else will pick up on it..good luck...Carl
 
"Buy the original manual if yo

"Buy the original manual if you can get it. If not, I find Seloc marine manuals to be alright. If your extremely cheap there are cd manuals that you can obtain on ebay. Just in my opinion though, I wouldnt waste my time on that motor. I read you did a spark check with no luck. Did you also do the compression test?"
 
"AGAIN, THANK ALL OF YOU FOR T

"AGAIN, THANK ALL OF YOU FOR THE DIRECTION AS WELL AS THE TIP'S..........I have not done a compression check as of yet, I will this weekend, The only I have done so far is to spay some stablelizer in the carbs as well as the 4 cylinders."
 
"I have a 1970 model 1150 whic

"I have a 1970 model 1150 which is a 115 hp.My wiring was fried also. Not having the proper equipment to test all of the parts of the ignition I found someone who was willing to test them for a small fee. I had to remove and ship them to him. He tested and returned all good parts as well as replaced all bad parts for a predetermined price. My switchbox, rectifier, and distributor were all bad and cost nearly $400 to replace with used parts. I was lucky to get someone who was honest and gave me back good parts that ended up working but it was a gamble. Do your homework before you put any money into that motor because it could get very pricey replacing ignition parts in the thunderbolt ignition system. Here is a link to another site I found helpful. http://www.pfs-ware.com/talkshop
Good luck"
 
"John, Im glad to hear you got

"John, Im glad to hear you got your motor running for just a 400 dollars.I only paid 150 for the motor, Im not sure I want to put that much money into it. I did test my switch box, I got a neg reading on the red, a positive on the blue and a neg on the white and no reading on the green? I took the fly wheel off, wasnt sure what I would find. If I understand this motor, It all starts with the stater, go's to the switch box, then the coil.....outside coil, not the one in the dis. cap?"
 
"Yea..........It's startin

"Yea..........It's starting to look that way.............I can either keep chaseing my tail or just part it out, power head, lower unit and such.......who know?.....lmao"
 
"Ebay in australia has repair

"Ebay in australia has repair manuals on CD for $4.50AU i just got one for my 1983 40hp merc and it covers Merc engines from 1966 to 2000 all sizes. it is in PDF Adobe format and is very helpful. Also i needed a new Switch box for my old 1976 70hp merc and got one for a good price of $80 from a boatwrecker here in OZ who i believe ships items worldwide.

http://www.acemarinent.com.au/"
 
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