'72 65hp 3 cyl fuel/carb probs... I think

[crewcabz]

Been around the block with this motor (a few times) replaced the fuel lines which meant the air box and adj. link on carbs had to be removed. It ran PERFECT (past tense) just leaked at a fitting. Cleaned fuel filter at this time also, since I had the lines off (had been done two months ago, but what the hey...) All three adjustment screws were exactly 5/8 turn out (oddly enough just like the initial adjustment stated in the manual). Re-assembled, set screws to 5/8 turn and now it wont idle for nothing. Not leaking at the filter housing, bowls are all full, pump seems to deliver consistent fuel supply, WHAT ELSE could it be? This was all done while the lower unit was being worked over (off of the boat) and re-installed... which took some force... so the engine was jiggled, shaken, etc in the tilted position before I attempted to re-start after the fuel work. I am wondering if the bowl was empty and I shook the snot out of this thing in the tilted up position if the carb/float/needle seat etc. might have been thrashed out. Before I pull carbs off and REALLY get into it, any input would be GREAT-

Thanks

 

[crewcabz]

Re: '72 65hp 3 cyl fuel/carb probs... I think

By the way, it is a Johnson...hydro electric on top of that. Getting to the point where I gotta keep it along side my collection of hens teeth

 

[jonesg]

Re: '72 65hp 3 cyl fuel/carb probs... I think

Maybe that lower end is binding up.?

 

[crewcabz]

Re: '72 65hp 3 cyl fuel/carb probs... I think

If I toss it into gear right after it fires, and give it a little throttle it comes to life... prop spin seams right (speed) and does not sound like it's under load. Playing with the choke and carb adj. seems to make some differance, but not enough. I'm inclined to think it is some unrelated consequence from my work... Replaced throttle cable today (old one was getting sticky)... no changes... ARGHHH! It's back in the garage instead of the water- New tank and hose next (just incase). Shot gun more parts and $$$!

 

[jonesg]

Re: '72 65hp 3 cyl fuel/carb probs... I think

I would drop the leg and try test running again.

 

[John Bussom]

Re: '72 65hp 3 cyl fuel/carb probs... I think

Been around the block with this motor (a few times) replaced the fuel lines which meant the air box and adj. link on carbs had to be removed. It ran PERFECT (past tense) just leaked at a fitting. Cleaned fuel filter at this time also, since I had the lines off (had been done two months ago, but what the hey...) All three adjustment screws were exactly 5/8 turn out (oddly enough just like the initial adjustment stated in the manual). Re-assembled, set screws to 5/8 turn and now it wont idle for nothing. Not leaking at the filter housing, bowls are all full, pump seems to deliver consistent fuel supply, WHAT ELSE could it be? This was all done while the lower unit was being worked over (off of the boat) and re-installed... which took some force... so the engine was jiggled, shaken, etc in the tilted position before I attempted to re-start after the fuel work. I am wondering if the bowl was empty and I shook the snot out of this thing in the tilted up position if the carb/float/needle seat etc. might have been thrashed out. Before I pull carbs off and REALLY get into it, any input would be GREAT-

Thanks

I am not an authority on this engine for sure or I would be out fishing instead of working on my 73 Johnson stinger but I am curious as to what set screws you are talking about
There may be some differences (I sure hope so) between 72 and 73 but I just went through my manual and cannot find anything with a 5/8 reversed turn, thought maybe I set something wrong!

 

[crewcabz]

Re: '72 65hp 3 cyl fuel/carb probs... I think

Three carbs on on the '72 65 HP three cyl. motor. Fuel/air mix adj. screws on each carb. Adjustments for idle and high RPM based on which carb you do... Rough and ragged explanation-

 

[crewcabz]

Re: '72 65hp 3 cyl fuel/carb probs... I think

I would drop the leg and try test running again.

May have to go that route... Seems like I'm flooding, but choke at high rpm actually helps. Makes me think I've thrashed something out of place in carbs. Same results in Nuetral (maintained nuetral by jumpering shift circuit) as dropping into gear... still thinking lower end? It'll have to wait a week now, too many other commitments

 

[jay_merrill]

Re: '72 65hp 3 cyl fuel/carb probs... I think

He's talking about the low speed needle valves. The high speed fuel metering is done with fixed orifices.

When you adjusted the LS needle valves, did you overtighten them, causing the needle to become crimped and deformed? Did you turn them back out from a lightly seated position? Did you then set the idle in gear, in the water, with a warm engine?

These are all critical issues and if you did the wrong thing on any of them, that might explain your problems.

BTW, I have a '72 Johnson 65hp that I run 2 - 3 times a week, 12 months a year. After I went through it when I bought the motor, plus a little further servicing in the first months afterwards, I ended up with a "rock solid" motor. In fact, I can thank it for my supper tonight - I have a few crab traps just for personal consumption and my trusty old Johny brought a bunch of them to my "bur-lin pot," late this afternoon!



???

 

[crewcabz]

Re: '72 65hp 3 cyl fuel/carb probs... I think

Jay... I seated the vavles by hand only (no screwdriver...just fingers), but did NOT turn them out off of the seat until I was re-assembled on hte whole motor (30-45 days). I was mainly hoping to keep the bowls full so as not to drop that needle valve and never seat it again. May have caused another prob. instead I guess. AWESOME to hear the praise for this old tank. Mine had minimal routine service in the first 37 years of it's life (Father in law's fishing boat) and is still a darn good runner ('till now). I figure it's like an old workhorse/seahorse... that's all it knows how to do! Any advice on the needles and seats? I'm doubting they're easy to find anymore... I'll keep you posted-

 

[jay_merrill]

Re: '72 65hp 3 cyl fuel/carb probs... I think

As long as the shift system is in good shape, these motors can be worth putting a few bucks in. Once you get the carbs straightened out, including a link & sync, plain on redoing the ignition system. The stators tend to do pretty well over time, but the powepacks and timer bases usually need to be replaced, along with the ignition coils. When you do this work, buy Sierrra and CDI parts - the cost of BRP parts has reached to point of complete stupidity. You should be able to get everything you need, right here at iboats.

If you look in the ignition section of your OEM manuel (Chapter 4), there are some simple tests that you can do of these components with a standard multimeter. See page 4-11. Depending on the results, you may want to replace some parts soon, or wait awhile, if the numbers look good and the motor is running well. Eventually, however, you'll probably have to do this work, unless someone else did so in the past few years.

Just to give you something to chuckle about, when I first got my motor almost five years ago, I was insanely busy at work and in life, so I sent it to my local OMC/BRP dealer to go through it. One of the lead mechanics, who I already knew well, snickered and told me that I was wasting my money of a piece of ..... well, you know. While I buy a lot of parts online, I often have to get things at the dealer (I have a bunch of motors), so I'm in the shop frequently. You can bet that I never miss a chance to pull the guy's leg about how well my '72 J65 runs! Every once in awhile, I'm also sure to ask .... "how much are those new ETEC 60 hp motors going for?"



???

 

[crewcabz]

Re: '72 65hp 3 cyl fuel/carb probs... I think

Awesome... Thanks Jay. I'm afraid my family will be outgrowing my little fishing boat in the next few years, but I'll atleast be able to tell the next guy an honest condition on the old Johnson!

Hey, I don't suppose you're anywhere on the West Coast are you?