1972 Chrysler 20 hp Runs intermittently

[Wilsonsk1966]

I’ve been fighting with a 1972 Chrysler 20 hp, model 202HD. I recently got it and it had a lot of little issues most of which were adjustments, I muddled through those and when starting it started hard, it’s a spool starter so it doesn’t spin the motor very fast, the emergency sheave and 5’ of rope spin it faster and I got it running but it took a lot of pulls cold. I checked the points they were around .015 so I regapped to .020, it fired right up, checked in the morning and one pull cold as well. Figured I had it fixed. Took it to the lake, ran great for 20 minutes or so, died, was pumping water and running great up til then, wouldn’t start again, even the next day. In checking plugs I found the grippers that make the connection to the plug in the boot were both really rusty. I had spark but it seemed intermittent. I got new spark plug boots and also a couple of the nova II chips, put those all on, started hard, didn’t want to idle, tried reverse polarity on the nova chips, ran the same, went back to points, seemed like it ran pretty good then popped and died, doesn’t want to start again now. I had 90/95 psi compression, not stellar but should run. I guess I haven’t been in the carburetor yet, in hindsight it feels like I have been misdiagnosing something I still haven’t fixed. I guess I should go through the carb?

thoughts?

thanks in advance.

 

[The Force power]

It would be a good start to clean the carburetor thoroughly blow out/clean, also check the fuel-lines/ the vent / the fuel-tank.

if fuel-lines are not replaced in the last 10-15 years; replace them.
if you can't clean the tank & don't know whats in it; test-run it on a different jug

 

[Wilsonsk1966]

Thanks, I’ll start going through the fuel stuff, I know I should have already done that but I kept chasing my tail thinking I had it fixed.

 

[Wilsonsk1966]

I pulled the carb, it’s spotless, nice simple carb. Everything looked great. I had put new line on from the can, I think the guy before me replaced the lines on the fuel pump. A couple notes I forgot to mention, it wants pretty much full throttle (as full as it gets in neutral) to start cold or hot, takes about 10 pulls or better cold, 4 or 5 pulls hot (wants full throttle hot too). That day after I gapped the points it started cold on 1 pull at home and 1 pull at the landing a couple hours later. It didn’t need a lot of throttle, started and ran normal til it died. I really thought the point gap had it fixed on Sunday, now back to this hard starting thing. It also seems like it loads up if I run it in neutral in the barrel for 5 minutes or so, I bogs a bit before raving back up again. I feel like it could use a good dose of wide open throttle, but I realistically don’t think it would help. It just seems I’m working around the problem on these other things. It still seems like ignition, I had high hopes for the nova II modules but they didn’t fix it and I’m unsure if they are really as good as points.

 

[Nordin]

I would suggest you to check how far the ignition coils can jump spark.
It should jump about 3/8 in in atmosphere at least 1/4.
Spark at the plugs.... yes but that is only 020-025 in in atmosphere.
In compression it has to have more energy and 1/4-3/8 in in atmosphere is okey.
If spark do not jump so far it can be the condensers or the coils.
I have worked with Chryslers and other brands such as OMC and japanese engines for over 20 years and coils used in Chryslers (Wico brand) last for really long time. OMCs coils from 60:es and early 70:es cracks and fail often.
9 times of 10 you have to change them because they are "rotten".

Also check the throttle pick up point.
There is a marked line at the throttle cam at timing plate.
The throttle butterfly should start to move when the roller is at the mark.
My experience are that sometimes you have to adjusted so it starts to move just before or just after the mark.

How is the air/fuel screw in the carb adjusted? Should be 1-1 1/2 turn out from seated.

Do a check again at the ignition system, clean the points really well and gap them to 020.

 

[jerryjerry05]

You didn't mention anything on using the choke to start the cold motor???
How long did it set before you got it?
Go through the carb again and make sure the jets are clear.

The more you try to start it the harder it gets, the gas/oil leaves oil on the intake side and that builds up
making it harder to start. Maybe clean the plugs or a quick shot of starting fluid.

Running for 20min then stopping: getting hot?
Or a fuel delivery problem: open the vent on the tank? One or more fittings leaking and sucking air?
Does the squeezie pump up firm? does it collapse when running?
Check the fuel pump diaphragm?

 

[Wilsonsk1966]

I don’t think it was getting hot when it died on the lake, it was spraying good out the back, didn’t give any other indication that it was hot, smelled normal, pulled over fine, just dead. I slowed and put it in neutral and it was at a fast idle and died, when I do get it to run that is typically when it dies, at a mid to high idle, just like you turned off the ignition. When cold it wants very little choke, choke til it fires, then choke off and it starts again. The previous owner did a lot of work to it, water pump, pump housing, he said it ran good but did say it started hard cold. He got fed up with a shifting issue that was just out of adjustment. I don’t know much history about it before that, he didn’t have it long. It’s really puzzling why it ran so good for a little bit on Sunday. One thing I have noticed when checking spark, sometimes I see more spark going from the edge of the electrode then off the end of it, nice and blue but more from the edge then the end. I’ve tried a couple different new sets of plugs. One other detail, It smokes like crazy, there was a couple gallons of fresh mix from the previous owner, I mixed up at 32:1 not knowing for sure what it should have. My experience with 2cycles hasn’t really been that too much oil (within reason) doesn’t cause running issues, just oily smelly exhaust. I could be wrong though. I just keep hoping to find something really stupid simple and it runs great again, these things aren’t really that complex, I have spark, fuel and compression, just something wonky with one or all of them.

 

[Nordin]

Fuel/oil ratio 50:1, 32:1 is to rich of oil.
Yes you have fuel, compression and spark, BUT check how far the ignition system can jump spark.
020 at the plug in atmosphere does not indicate good ignition system.
3/8 in in atmosphere or at least 1/4 in, then you know it would create spark at compression.
The components (condensers and coils) get hot when running and they can fail when getting warm.

 

[jerryjerry05]

Fuel/oil ratio 50:1, 32:1 is to rich of oil.
Yes you have fuel, compression and spark, BUT check how far the ignition system can jump spark.
020 at the plug in atmosphere does not indicate good ignition system.
3/8 in in atmosphere or at least 1/4 in, then you know it would create spark at compression.
The components (condensers and coils) get hot when running and they can fail when getting warm.

Nordin probably covered it when he said the condenser and coils get hot and fail.
I've found that you can touch the coils and while they're hot, but not hot enough to burn you.

 

[Wilsonsk1966]

This sounds like a pretty dumb question but what’s the best way to see how far the spark will jump? Never had to look at that before?

 

[Nordin]

Put a steel pin or similar in the plug boot and hold it about 1/4-3/8 in from engine block (some place where there is not paint) and crank it over.
Maybe you have to have an assistant or you fix something that hold the HT boot in place so you can pull the magnapull with out holding the boot.
If you are a bit handy you make an adjustable gap tester by your self or buy one (but they are not cheap) from CDI electronics or some other OB ignition tool shop..
I have made one by myself from some screws and plastic blocks. It can handle a 6 cylinder engine.

 

[Wilsonsk1966]

I saw guys do that back in the 70s, always wondered why they didn't just use a plug, now I know, I can rig up a plastic c-clamp frame and make it adjustable and consistent. I also was wondering about how well the ignition plate with the points and coils in it is grounded, I see a wire going from that to the block, I'll check that too, while it's not always the cause, bad grounds can cause lots​​​lots of weird stuff.

 

[Wilsonsk1966]

I take the plugs out and spin it with a drill to check spark.

 

[jerryjerry05]

Auto Zone has a spark tester that you can use to measure spark.

 

[Wilsonsk1966]

I built a spark checker, both plug wires snapped nice big blue arcs. I hadn’t messed with it since last week, I put the plugs back in and primed it, fired on the second pull with choke, choke off, started on the 3rd pull and ran great. Idling pretty well too, I let it run for 5 minutes, shut it off, started on two pulls, ran another 10 minutes, shut it off, wouldn’t restart, I quick put my spark checker in to see if I had heat related loss of spark, both snapped across the big gap. I put the boots back on and gave it a shot of ether, nothing. I mentioned my extra oil-heavy premix, is it possible it’s drowning in oil?

 

[jerryjerry05]

Yes replace the plugs.
These 2 strokes the more you run them at slow speeds, the more they clog
with oil.
I clean them with Dawn or carb cleaner, blow dry then a propane torch, i get them hot, then cool them off
that seems to make them fire quicker.

 

[Wilsonsk1966]

Is it just possible I'm choking this thing on oil? I pulled the plugs this morning after running it a bit last night, a big gob of carbon was bridging the spark plug gap. I washed the plugs in dawn dish soap, hit the wire wheel with them and sprayed them with contact cleaner (no residue) to dry them. Started on 4 or 5 pulls, not awesome but I did get it to restart on 2 to 3 pulls a couple of times. I'm going to dump the gas and mix up fresh 50:1, like I said, I did 32:1, the PO may have been going rich too as it was new to him. How do I de-carbon it?

I'm attaching one of the plugs from when it died on then the other one looks pretty normal but this has a ring on the insulator...

 

[Wilsonsk1966]

I see I muddled up the words about the spark plug with the weird ring on the insulator, this was one of the plugs from when it died on the lake after about 20 minutes. I was in no wake zone so just putting along, I actually slowed down because it was smoking so bad to see if it was pumping water (it was) then it died and wouldn't restart. Could this all be carbon and too much oil?

 

[Wilsonsk1966]

I picked up a pint of Sea Foam, I'm going to try to de-carbon it, I have a recipe of 3 quarts gas, 3 oz oil, 16 oz Sea Foam, run for 15 minutes, let it sit for 15 minutes, do this 3 times. We'll see how it goes. I don't think spark is my issue. Hopefully I can get it running decent enough that I can try the Nova II modules again and see how they work when I'm not fighting a couple of other issues.

 

[Wilsonsk1966]

This is after round 1 of the sea foam treatment, I see that ring on the insulator on the lower plug. Thoughts?