1971 100 hp complete tuning sequence (can't find detailed instructions)

[thelegion]

That's pretty slick, there is no reason those switches should be that expensive other than people hoarding parts for later resale. I've fixed the wires on mine and their cheap cheap quality.

 

[jbuote]

Well, that and It seems the switches aren't manufactured anymore, so the rarer they get, the more expensive.. lol

​Anyway,
Didn't mean to digress or sidetrack you from your issue at hand.. LOL

 

[thelegion]

Thumbs up,

I'll rip it apart after work today "again" and see what I come up with with that spring. I'll take a picture and see if I can label it with numbers, maybe some form members can jump in and comment, or even better maybe someone can scan a couple of pages outa a good shop manual and post em on tuning sequence.

After work,

I pulled apart the throttle linkage and it's a combination of the old stiff wire covering fron the timer base and lube that touches any of the linkage. I cleaned it and used a dry lube and the timer base follows the throttle linkage nice, it's worth a note that tempature has a huge impact on any type of greasy lube you use.

There were some funny wavey washers tossed in linkage too with the cottepins , all these little restrictions add up and lessen the spring effectiveness. I have learned since starting this that you never know what the previous owners have done and have put back wrong or just guessed at, and where washers went after sitting on a bench for many weeks.

One of the biggest issues I found is the previous owner had 1&2 plug wires mixed, not to mention all 10+ tiny things that add up to "why won't this tune " . All said, I've had it almost perfect on the water , this motor will push a 94 16.5ft campion to 60kmh/37mph.

So if I'm rambling it's because I think they're worth saving, providing you don't need to re mortgage the farm and you have something worth saving.

 

[thelegion]

No Title

So this is how I started my tuning, I have “no” idea if this is correct or not. The motor will flash right up when warm or hot, I’ll do a cold start tomorrow and post results.

1. removed the throttle cable

2. I loosened the timer base stopper 2 and aligned mark on distributer (really hard to see) with base stopper

3. backed off “4” and align the start arrow “3” so the switch plunger “5” mates up with the bottom grove behind the start arrow, look close there are two groves. then I adjusted 4 in to the stop.

4. I then removed 7a and adjusted 6 out, (without washer and cotter pin), I then put 7a and 6 back together minus washer and cotter pin to do a function test. By grabbing the base of the throttle I advanced the throttle to full making sure the stop pin 7b was just touching the carb body.

5. adjust the throttle linkage stop 8 so you can just see light between the roll pin and carb body and then tighten 8.


I had to mess with sequence 4 a bit to get the roll pin nice and close to the carb, and then used 8 to make sure the roll pin did not hit the carb at full throttle.


Now when I started it appeared the throttle butterflies were in sync, I did not adjust the screw 7c as it was not going to budge and I didn’t want to break or bend anything so I left it alone.

6. I then turned the slow speed needles in (9) and and backed them out 1.5 turns, I then primed the carbs and started the motor while leaving 1 disconnected. After the engine warmed I began to tune the SS needles, I have a big test bucket the leg can sit in, when it sounded nice and after all 4 needles were adjusted the rpm’s were fairly high so I turned out 4 maybe 1/2 a turn or until I thought it sounded fine.

7. I then connected 1 and adjusted 1a till it lined up with the post on the throttle arm and locked it in.

So that’s it in a nutshell, I’m sure there was a bit of fussing here and there. Like I said “I don’t know if this is correct” but so far so good. I will have to get it in the water to check WOT.

 

[racerone]

The full throttle stop ( 2 ) is set at the factory and requires no adjustment.----Unlesss of course it was tampered with.-----Check full throttle advance with a timing light now.

 

[thelegion]

I guarantee it was messed with, now I don't think I can time it in a bucket can I?

 

[jbuote]

Nope.. not in a bucket..
​If you had a proper test "Tank" with the right Test Wheel for the outboard, then you could do that..

Otherwise,
​Could use the Joe Reeves method:
http://forums.iboats.com/forum/engi...ns-faq/234008-joe-reeves-wot-timing-procedure

​Only other way would be on lake at speed..

 

[thelegion]

A follow up to "cold" starting, it's a bugger to start cold.

 

[racerone]

If it is hard to start then there is something wrong.--You have to know the basics.--Have you looked at adjusting the choke solenoid ?----Advancing throttle properly ?-----Not the same as starting a modern car !

 

[thelegion]

I'm learning as I go, by braille

So, when the motor is cold I start by

priming the fuel bulb to firm

ignition on, then the auto choke (solenoid) will do a 1/2 choke on its own,

lift the start lever which advances the throttle

turn it over and fingers crossed


There is a full choke toggle below the key and I'll hit it to encourage things along but I don't think it likes this for some reason. Should the solenoid be "full choking" on it's own when cold? I can and have adjusted it up and down in the bracket to get it where it looks right.

My current shop manual stinks and a year specific one is on the way. I just built a spark tester and will time it the next reasonably nice day. My motor has the pointer with the screw hold down for timing. I read that I also need to find tdc on #1 and then rotate the flywheel counter clock wise until #1 comes back up to tdc, then measure the distance between the two marks and divide by two to set the pointer and then time off that???

This motor seems to be a royal PITA to tune!

 

[racerone]

You have to use the full choke switch when motor is cold.-----The thermo-electric choke stays " on for 1/2 choke " untill motor warms a bit.-----Most of those had that feature disconnected per a service bulletin.

 

[thelegion]

So should I disconnect the thermo choke and use either all choke or nothing?

 

[jbuote]

For what it's worth, That's how my 71 50 is set up.. No auto choke, and it's either Full choke or No choke via the toggle. (push to choke on mine.. lol)
Mine however, the wires were cut to stubs at the sensor on the block.
The only way I could get partial choke is to use the manual lever at the engine itself, which I've yet to have to do..

​Like I said before, maybe disconnect the auto choke without cutting anything so you can hook it back up if you want, but at least you can try it without the auto choke and see if there's a difference..

Worth a shot? lol

 

[thelegion]

I'll try the full choke cold.

I just finished making a spark plug gap tester and it appears my timing is 28 deg, -4 deg as per "joe R" recommends.; so after I try the full choke I'll give the timing a go.

 

[jbuote]

I guess I have to wonder, being new, if the Auto choke is holding 1/2 choke, which is not enough on it's own, but then too much after full choke to start..
​
​I don't know.. Maybe what I mean is, that with the Auto Choke still active, you'll only get Full choke or 1/2 choke till it warms up.. ONLY when warmed up, would you get full or no choke, but by then you wouldn't need the choke.. lol

​With Auto Choke disconnected, you'll get full choke or NO choke all the time.
​Maybe that's what you need so you can then bump the choke when it stumbles to keep it going till it warms up?

​Really just newbie(ish) guesses, but throwing the thought out there in case it's worth something.. :noidea:

 

[thelegion]

I'll try all the ideas, one thing I noticed or it just might be a coincidence is, when it's not starting I will seat the 4 needles in and back them out 1.5 turns and this seem to get things going. I even tried a squirt of fuel in the carbs and you would think that would kickstart everything, but Noooo. There has to be something so small and overlooked on my part thats causing this. Like I say, it starts like a beast when warm.

 

[thelegion]

Cold Start,

So today after work I disconnected the auto choke and pulled the manual full choke out and gave it a couple of kicks with the key and "whala" it started right up. I then looked over and noticed I didn't pull up on the start lever, hmmm? after it started to run I closed the choke and toggled up the start lever to give it a bit of a warm up boost.

So now what do I think, have I been flooding it all along? I know it's not rocket science but really. I guess every motor just has it's own quirks and this one my not like a fuel heavy environment.