1971 35 hp will not open up need help

bstroupe · Oct 23, 2011

I have rebuilt carb and fuel pump. Carb adjusted at 2 turns out. replaced pulgs, points gaped at .20, and replaced 1 coil its getting good fire. The problem is it won't open up it just boggs down. doesn't matter how you set the carb. Also getting fuel out of the two small drain holes just above the foot. Also replaced gaskets in foot and impeller. acts like it has a miss. The cam is new as well. The old one was broke just befor the lobe. Can anyone help me I have done everything I know. Please help.

fucawi · Oct 24, 2011

Re: 1971 35 hp will not open up need help

Sounds like the float level is wrong or (I have had this ) the needle valve seat is no good ...1 1/2 turns out from a light seating is enough. Also ensure all passages in the carb are clear ..blow with compressed air ...

jerryjerry05 · Oct 25, 2011

Re: 1971 35 hp will not open up need help

Compression???Then try rebuilding the fuel pump.Profile??Ethanol?
Ethanol is messing with a lot of old hoses.Soft/mushy?
First thread in the Force forum from FrankA is called a linc and sinc.do this too.J

bstroupe · Oct 25, 2011

Re: 1971 35 hp will not open up need help

I rebuilt the fuel pump when I built the carb. The compression is within 2psi between the 2 cylindres. I am going to set the float level and try that this weekend. I will keep you posted.

fucawi · Oct 25, 2011

Re: 1971 35 hp will not open up need help

you can set the float level but if the needle valve is bad you are wasting your time ..blow into the fuel inlet and see if moving the float up and down cut off the air flow.
Are you sure the flywheel has not moved as its linked to the timing ring ....could be a timing issue ..if the carb is good that is where I would go next ..ie take flywheel off .

patrickj · Oct 25, 2011

Re: 1971 35 hp will not open up need help

my 85 horse force did this would start and run fine until you went wide open... i had water in my fuel and lots of it.

fucawi · Oct 25, 2011

Re: 1971 35 hp will not open up need help

appreciate your input pat but I tend to asume...... maybe wrong that people have the very basic covered before asking for help ....

wickware · Oct 25, 2011

Re: 1971 35 hp will not open up need help

A broken cam is new to me. Would it be asking too much to post a pic of the broken cam close to the new with their direction arrows showing? Please double check the point?s gaps with one showing opened in the pic. So I can check the gap at the right cam location. LOL!

On my 1970 35 HP Chrysler the bogging has always been dirty points vs burned since 1985. I have only changed the points once in the 80s as routine maintenance since the motor was new to me. Plus, I have not touched the timing. Only running it summers 6-12 gal of gas on an avg probably save something. Short runs w/n good for the engine, it ran better after wot 5 mi trips and Sta-Bil Etc.

Good Luck! I am sold on the 35 HP for fishing at short distances. jow

bstroupe · Oct 26, 2011

Re: 1971 35 hp will not open up need help

I have found a wiring problem. The top cyl. not firing. I have a short some where. I am getting 12 volts all the way to the coil, but also 12 volts on the engine block. I have to trace wires and try to find it.

patrickj · Oct 26, 2011

Re: 1971 35 hp will not open up need help

i had 2 marine mechanics look at mine, one replaced the fuel pump, the other told me it was my stator, my wife noticed there was water in the glass filter when i was running it in a barrel. hooked it to a portable tank after draining the carbs, ran perfect, so id assume... but i may be wrong that not everyone would check for water in the gas when their motor will start fine.

As for the wiring problem it sounds like you have a chaffed power wire shorting to the block but im not sure it would cause your cyl to not fire, seems like if it were to cause a cylinder to not fire it would cause both not to fire, im not sure how the coils work on the 70's but i assume its one of the ones that has a non removable plug wire, the coil maybe shorted inside causeing you to read 12 v to the block.

bstroupe · Oct 26, 2011

Re: 1971 35 hp will not open up need help

No water in fuel. Always check simple things first. Number one rule. I'm a 20 year auto mechanic. Boat motors are new to me.

wickware · Oct 26, 2011

Re: 1971 35 hp will not open up need help

Troubleshooting:
1. With your points closed, check for continuity between the contacts with your meter.
2. Switch your condensers to see if your problem switches.
3. Switch your coils to see if your problem switches.
4. With the plugs out, I would think you could spin the flywheel by hand to check the fire.
5. A few shots of my 1970 35 HP?s magneto dist.. jow

bstroupe · Oct 26, 2011

Re: 1971 35 hp will not open up need help

Nothing changed. I tried all 4 sugestions. Everything is going to ground. That can't be normal can it? I don't under stand it. No wires touching. No naked places on wires. I even took the starter off, didn't change. Could it be the key switch wired wrong? Or could it be bad? The pics look just like mine. What all this is doing is with a multi meter if you put the black or ground probe on neg batt terminal then touch the red probe to anything grounded on the engine even the block you read 12.5 volts. I can't figure out why.

wickware · Oct 26, 2011

Re: 1971 35 hp will not open up need help

My troubleshooting was related to the bogging vs the grounding problem. The ground issue is one I have not seen. You might try a PM to Frank or some of the Technicians that have more experience (on the old Chryslers). I am trying to visualize this issue w/o it being a short and killing your battery. jow

Frank Acampora · Oct 26, 2011

Re: 1971 35 hp will not open up need help

The blue wire on the switch is connected to the "I" terminal. It supplies power to both coils anytime the switch is on. There should be two siamese blue wires on the engine terminal going to the pos of each coil. Off the neg of each coil there should be a white wire going to one set of points. The points are normally closed, allowing the power through the coils. When the points open, the power is interrupted and the field collapses, generating the high voltage spark pulse. One set of points controls one coil. BOTH must be set to .020. If one set is either constantly open or constantly closed, or if that set is incorrectly adjusted, corroded or oil fouled, that coil will not produce spark. Check that no wires are rubbing on the flywheel and check that the condenser is not shorted.
JOW showed the magneto ignition. Battery and coil is the same except for the wiring and an alternator stator in place of the two magneto coils.

bstroupe · Oct 26, 2011

Re: 1971 35 hp will not open up need help

The blue wire only goes to the lower cylender point set. The white wire goes to the upper one. Do I need to make a jumper wire to go between them?

Frank Acampora · Oct 26, 2011

Re: 1971 35 hp will not open up need help

Yes. Wire it as I described: From the engine terminal where the blue wire from the switch attaches run another blue wire to each pos. terminal of the coils. Then run a white wire from the top coil neg. terminal to the top set of points and another white wire from the bottom coil neg. terminal to the bottom points. Top coil is obviously the top cylinder. I am not certain, but I think the rear set of points is the bottom cylinder. If you set up the electrical and turn the flywheel by hand, it will show if the correct set of points is wired to the correct coil.

Do not leave the switch on when the engine is not running. One set of points will be closed and you will drain the battery in addition to possibly shortening coil life.

bstroupe · Oct 30, 2011

Re: 1971 35 hp will not open up need help

I just today got the chance to work on it. I found and fixed the ground problem, bad wire. The one cylender still would not fire, A bad brand new condenser. Running and ideling fine. Going to the lake friday or sat and we will see. Thank all of you for your wisdom and advise thank you once again.

B.Stroupe

1971 35 hp will not open up need help

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