New Boat Owner

[boostin_7]

Hi all.
My name's Greg & Ive recently purchased a 70's Bellboy Speed boat with 1966 100hp Johnson outboard.
When i acquired the boat it wasn't running, but since then I've remedied the starting issues with adding the factory fitted nut to the top of the starter assembly & using a Optima dry cell starting battery.
Since then Ive used her on the ocean for 2 fishing trips & all has been good until this weekend when i took her skiing down the river for the first time.
Firstly, when we arrived she wouldn't start & i had to pull all the plugs, crank to clean her out, then plugs back in she ran fine.
Q: What may i have done to make it flood so badly, possibly pumped the primer bulb too much?

Secondly after around half a day of skiing, the battery was drained to a point where it could no longer kick the engine over fast enough to start. I decided to pull the lid & she pull started fine, so off we went for some more skiing. When i got home i tested the alternator diodes & they seem to be stuffed because they measure close circuit both ways with the diode tester (my understanding is that a diode works by only letting current flow one way & when coupled like on this battery ignition style motor with another set it converts the alternating voltage generated into a DC for battery charging).
Q: Does anybody know where i can source parts like this for such an old engine. Ive got access to the part numbers but are having trouble finding stockists.

And thirdly, we werent paying attention to the fuel level & we ran one tank out & the engine stalled. I flicked the switch to the second tank, squeezed primer bulb until firm, but couldnt get her to pull start again.
The first time i pull started her, it was very easy to pull. This time it was extremely hard to pull. After about 10 goes, i decided to call it quits for the day & rowed back to the ramp.
Q: What seems like the possible cause here?

Also i would like to get the engine tuned & serviced professionally, as there is a miss/hesitation point at mild throttle. Then when once you extend throttle to a certain point it ramps up speed without adding more throttle, then it slowly dies off again. So you add more throttle & it over speeds again then slowly drops again.
I got used to it to a certain degree, but it was really hard on the wakeboarder i was pulling.
Does anyone know of an outboard mechanic/tuner in Adelaide that would be interested (& have the knowledge) to work on such an old engine? Ive ran a couple of places & the standard response i seem to get is to buy a newer motor.
Id really like to just get this one sorted though.

Sorry for the long post, but ive got a lot on my mind..: )

Any advice would be greatly appreciated,

Greg

 

[mekkamaz]

Re: New Boat Owner

Ok, First of all if the carbs float valve maybe dirty and this will flood your engine. If that is clean and close well by simple priming the bulb you cannot flood the motor. Also if you choked a lot, maybe you can flood it. Check if the float valve are ok.

On your rectifier, I do not know what kind this yr has, but if it has 4 wires (2 for the ac and one v+ and v-) then you can swap it meanwhile you get the original for a diode bridge, amps according, of course, or simply go higher (40 A).

Finally, I think that gas have not reached all passages, and maybe you were tired by this time!! LOL..You only try again...If this does not work whit your fully charged battery, let me know and try to figure it out...

 

[boostin_7]

Re: New Boat Owner

Thanks for the reply mekkamaz.
I will check the carb float vlave as soon as i get the chance. To be honest I havent played with carb setups at all, as Im a reasonbly young guy & every car Ive owned has been EFI.
In regards to the rectifier, I read through my new service manual & realised that Id tested the diodes wrong. I did the diode test across the terminals instead of between each terminal & an earth reference.
Now Ive re-tested them I see they are working fine.
According to the manual, when i turn the ignition on the Amp meter should move slightly to the negative side, if it moves to the positive then something in the system is wired in back to front.
The needle on my meter moved to the + but i cant work out whats around the wrong way. All the wiring to the diodes/regulator/battery/starter ectonly appears to wire up one way?
Finally, with a new battery I got the engine to fire up yesterday But didnt get to do any more testing because i had to go to hospital for some surgery. Hopefully by the weekend Ill be rested up & will measure the battery voltage before & after the engine is running with a flush attachment.
Oh Its a 1966 100hp with distributor style ignition system

 

[mekkamaz]

Re: New Boat Owner

Ok. Hope to be any help. REgards.

 

[boostin_7]

Re: New Boat Owner

I fired the outboard up again today & it appears the charging system is working because the voltage at the battery went from 12.8v to 14.5v with it running. Maybe all the cranking at the start of the day trying to start the flooded engine drained enough of the battery, so that when we accidently left the ignition on for 20-30mins when eating lunch it no longer had enough to fire it up again.

 

[inthedirtagain]

Re: New Boat Owner

I have the same outboard on my 1966 Starcraft Holiday. When I turn the key over to the "on" position, I get a slight discharge showing on the voltmeter. My manual doesn't state that this is a normal condition, so thanks for that info. But what my manual does state is that the charging systems on these older O/Bs are not all that strong. If I am remembering correctly (manual is not in front of me), it is only putting out 20A @ WOT. Leaving the key in the "on" position while having lunch is a sure fire way to deplete the voltage in the battery, especially with multiple starts throughout the day and a long cranking session to fire it up at the start of the day. If you are worried about voltage drain in between uses, keep a solar trickle charger hooked up to it. If you are like most, you aren't on the water every day, so the trickle will help keep the battery topped off at all times.

Out of curiosity, what size prop are you using and what kind of speeds are you getting out of your boat/motor combination? With my 18ft aluminum Holiday, I've reached a best of 32mph with our family of 5 and all our skiing crap/food. This is with a 12x14 3-blade, but I also have a 12.5x16, but I lose holeshot with that prop.

 

[boostin_7]

Re: New Boat Owner

I normally leave the battery on a trickle charger when not in use, but would love to try & get a larger amperage charging system working in the boat so i can run a stereo without drawing more from the battery than can be replenished.
To be honest, i dont have any idea what spec my prop is.
Basically i was looking to buy a small fishing boat & when i saw this one i thought id give it a shot on the river as well. I was told by a couple of people that i'd struggle to pull a wakeboarder out of the water, but if i throttle on hard & ease back a little when the boat starts levelling out it does a decent job.
Are there any ways i can check the prop specs? Its got 3 blades & i cant find any markings on it anywhere. I got a brass prop with the boat also.
The speedo on the boat isnt working yet either, so im unsure of what speeds we're hitting.