1971 50hp

[larky]

just bought this motor and its running rough. a little bit of a skip while running. the guy i bought it from said it needed carb work, but was otherwise fine. I will take that with a grain of salt. so assuming he was correct i took the carbs apart and cleaned them the best i could with compressed air and a small wire. the top slow speed needle looked a little worn. it probally needs to be replaced, just dont want to start throwing parts at it till its fixed. has good spark checked that with 1/4 inch gap spark tester. plugs will be replaced as soon as napa opens this morning.
any info is always greatly appreciated.
model# 50173s

 

[tashasdaddy]

Re: 1971 50hp

i have the same motor. totally clean the carbs, remove the highspeed jets, and the core plug on top to clean the idle ventris. reassemble with a new kit. spark needs to jump 7/16" You do know it is hydroelectric shift. you need the special screwdriver to remove the jets.

 

[larky]

Re: 1971 50hp

thanks for the reply TD. I will start making the srew driver in a few minutes, seen the diagrams of it on other posts. about the plug on the top of the carb can you get it out and reuse it or does it come with a kit? and i will also open the spark tester to the 7/16 gap. thanks and i will let you know how i do.

 

[larky]

Re: 1971 50hp

also what did you mean by "you do know it is hydroelectric shift", is this a good thing or bad. one other problem is that when i go to shut it off it shocks me from the key. didnt need my morning coffee after that
one more thing TD i also got my 1971 50hp for $150

 

[tashasdaddy]

Re: 1971 50hp

that's what i paid for mine. the lower unit has solenoids in it, take direct the oil flow to shift the gears, use only Premium Blend Type C gear case oil for electric shift motors. you have a short (bare wire) in the control box shocking you. here' link down in it Joe Reeves explains electric shift, save it for future reference.
http://forums.iboats.com/showthread.php?t=166519&highlight=electric+shift

 

[elmogilmo]

Re: 1971 50hp

i have about the same motor 60 horse, which ran long enough to impress me in as much as quick starts nice idle throttle response until I put it in gear where it just wouldn't accelerate, accelerates fine in nuetral tho, back to the house troubleshooting in the barrel when surprise no spark at all, few minutes later spark comes back. I notice an electric pop or click around the terminal bar, with all those wire connections, any help appreciated.

paid 250 for this one

 

[larky]

Re: 1971 50hp

Allright carb kit is on order from iboats. On the BRP parts diagram(#38) they show a "needle valve bearing", is this something I should remove and clean and does it come in the kit? Next I checked the compression (with engine warmed up) and the color of the plugs. The compression was 140# on the top cylinder and 135# on the bottom cylinder. I will do a decarb and then check again. Now the top plug looked like it was running a little rich and the bottom looked a little lean. And the last thing was the spark. Adjusted my spark tester to the recomended 7/16 gap and it looked great. So in conclusion I'm hoping the carb kit will do the trick. Any words of wisdom on rebuilding the carbs, any tips or tricks?

And thanks alot for your time and experience

 

[BoatBuoy]

Re: 1971 50hp

...use only Premium Blend Type C gear case oil for electric shift motors. http://forums.iboats.com/showthread.php?t=166519&highlight=electric+shift

Use BRP Premium Blend NOT Sierra Premium Blend. If using Sierra, use Type C.

 

[F_R]

Re: 1971 50hp

The needle valve bearing is way deep in the hole. If it is worn, air will be drawn in around the needle. Remove it with anything you can devise to hook it and pull it out. Your wife' crochet hook will work. Some people start a long drywall screw into it and use that to pull it out. It comes with a kit.

 

[larky]

Re: 1971 50hp

thanks Boatbuoy and FR for the info, keep em coming

 

[larky]

Re: 1971 50hp

as i continue to reflect on the test run i think of more questions. this problem maybe fixed when i install the carb kits but I'll ask anyway. when i lake tested my motor and would put in gear it would idle down then die. I read that the idle should be set while in gear, so i did. but when it comes out of gear and aslo back into gear its rpms are a bit high and when you shift it will make a clunk louder than i'm used to. At what rpm is it ok to shift without damaging the cluchdog? tell me your ideas.

 

[tashasdaddy]

Re: 1971 50hp

you want your idle in gear 600-700.

 

[larky]

Re: 1971 50hp

ok did the carb rebuild, adjusted per joe's instructions, a little better idle, more peice of mind though.

some things i noticed were when the hood was off and the air silencer plugs were removed that thing would scream down the lake, but with them in place the rpms weren't as high. aslo when i was at WOT and backed off the throttle a little the rpms would increase a bit.

I know i need a manual.......but the wife will kill me if i go spending more money, maybe i'll sneak in an order for one in a month or so

Is it too much to ask to explain the link-n-synk prosess???? or maybe its some thing else