1975 105 chrysler no spark

[Rpetersen]

1975 glastron 18 tri hull w/105 chrysler
Bought it end end of summer twoyears ago. I already have a 16' tri hull w/100 hp chrysler on it major transom issues. Saw the 18' for $400 couldnt pass it up.started up and ran great. Used it a few times that year and again the next year no problems.my oldest son stops by and we decide to take my younger two boys tubing. Start packing the boat up I hand him same quart of two cycle and ask him to pour it in for me. So we stop at gas station put in 12 gal. Gas and we are gone motor starts up runs great for about 10 min. Or so, died ,started it and started to accelerate died again to never start again.I know a little about repairs I (THOUGHT) I had good mixed gas in there because I just put it in myself. So I started thinking spark. I have the 100 horse and a bunch of extra parts.so to end this quick after several days of swapping out parts to no success I finally give up. Siphon the gas to park it for winter turns out my son somehow managed to put down the two cycle and he must have picked a gal. Of my used motor and and poured that in the gas I took out was so black I could not believe my eyes by the time it got to the bowl oil must have settled enough for me not to notice !!! Everything has been checked or replaced tried to start had spark couldnt get gas floats were set wrong reset and tried again fixed it. NOW i can't get spark !!!! New plugs wires reset points .010 good spark from coil to distibutor but not to cylinder. I have checked everything ten times need some help plese

 

[Nordin]

If you have spark from ignition coil but not to the sparkplugs the issue is in the distributer/distributer cap.

Check the hightension wires from cap to plugs and the center knob in the cap for the rotor and also the rotor.

 

[Rpetersen]

I will after work tomorrow and let you know how it goes thank you for the fast response desperately need to get on the water

 

[Rpetersen]

No luck regapped points,wires look good rotor seems to be a little worn it is at a little angle.is .010 correct gap? Is there a way to test points?

 

[Nordin]

Yes you can test the points. If you have a VOM check for resistance over the points.
If okey it should read 0,0-0,5. It depents on how good VOM you have and have good the test leads are.

BTW. Do you have the Magnapower CD box or aftermarket box. Or is it converted to automotive typ battery ignition? You say you have spark from coil.
How do you test for that? Are you testing with the points acting as trigger.

If you have Magnapower CD box or aftermarket you can test the CD box by unscrew the white/black wire at distributor and with the ignition key in ON position, number one piston at TDC and number one plug connected and grounded, srcatch the wire to ground and plug should spark.

If you do not have CD box and have a automotive battery ignition system you can do the same test.

Please inform how you do the test for spark from ign.coil.

 

[Rpetersen]

Not sure what I did but now I have spark and in all 4 cylinders now I'm only getting fuel in number two and number three it backfired once through the exhaust and that's all I got no clue as to what is happening

 

[elliotlake]

Rpeterson. Good luck. I am new to repair side of my 78 140...intermittent spark. Had it running. This is getting to be an adictive challenge. My wife wants it junked - not.
Indebted to each of you and previous mentors (auto ignition seems to offer new hope)
Will be gone for a month - I want to beat Cdn winter.

 

[Nordin]

Backfire is a timing issue.
Have you checked the flywheel key if it is shared?
If you put a screwdriver in top cyl. hole and check the TDC it should line up with the TDC mark at timing pointer.
If that is okey also check the curve at distributor pully. It should follow the flywheel rim.

 

[Rpetersen]

I have checked flywheel key still good

TDC GOOD
DISTRIBUTOR GOOD
Any other things to check
If it has spark and some gas it should at least fire a couple times shouldn't it ???
Could the spark not be strong enough ???
I am a couple hrs away from looking for a new motor and I don't give up very easy,but it's been too long now.
If u have any ideas I am willing to try anything
Really appreciate the help THANKS

 

[Nordin]

As you says the spark is good I assume it is sparking at right time. That is why I ask for the flywheel key and the curve at dist. pully lines up with the flywheel rimm at TDC #1 cylinder.

Then you have to check for fuel. Is the plugs get wet?
If not, clean the carbs and check the reeds for damage/broken or not sealing properly.

If wet plugs, then check the fuelpump diaphragm for crack/hole.
If bad diaphragm fuel can flood the cylinders.

BTW Have you checked the compression in all cylinders?


Converting to automotive battery ignition is not hard.
There are a couple of videos at Youtube, and as you have a points distributor you only need a automotive typ ignition coil, a condenser. Small changes in the wiring and change the plugs from surface gap style to regular with bent electrode.
NGK B6HS; B7HS or B8HS would fit.

 

[Rpetersen]

I have checked the fuel pump diaphragm looked good.
I did not check compression.
Last attempt at starting had spark all cylinders fuel only in #2 & 3 .
1 & 4 were dry does not make any sense
I am putting every thing back together today for one more try Thanks again I will let u know how it goes