Need An Experts Opinion on 1974 20hp Chrysler

[grizzrider09]

Alright guys I got problems, My motor will crank but will not run unless your squezing the bulb. Put new fuel pump kit in does the same thing. Took the motor to my mechanic who I trust knows his stuff and he cleans the carb puts anthor fuel pump in and the motor still will not run without squezing the bulb. He says he thinks its a tube in the carb sucking air and not fuel so we put a new carb on it and still the same thing. He then says the only thing he knows to do is change the reeds inside the motor but if its not that then the motor can be junked because it needs to be rebuilt and you cant find parts for these motors. My question is why cant I get it rebuilt? Do they not make pistons for them? I guess this motor has some sentimental value being that my grandfather owned and ran this motor when I was a child and he would take me fishing with it. I dont wanna give up on it. Any recomendations?

 

[emoney]

Re: Need An Experts Opinion on 1974 20hp Chrysler

I wouldn't give up, just yet, although I'm not sure how rebuilding it would correct a fuel issue. Not that I know much. Are you going to have him replace the reeds, or not?

You'll find a lot of mechanics that don't want to work on old Chryslers, mainly because of the parts availability issue, but also just because of rumor and innuendo. Folks in the same profession tend to talk, just like boaters talk to other boaters, and if one guys says "you can't get parts", before you know it, you've got 10 guys saying the same thing. Before I made any decision, I'd wait for one of these Chrysler guys here weighs in with an opinion as to what the problem may be and go from there. Might even be tomorrow before they reply, but they will reply. Out of curiousity, and I know this is simple, but does the motor act the same way regardless of which fuel tank you use? What I mean is, have you tried another gas tank to confirm it still won't run? I'm sure the mechanic checked that, but you never know, and I've had motors not run because of a bad vent on the tank. Just a thought while you're waiting.

 

[Frank Acampora]

Re: Need An Experts Opinion on 1974 20hp Chrysler

A couple of years ago, I bought the last two pistons in the USA. Wiseco will custom-make pistons but there is an 800 dollar upcharge so you would need a market for a number of pistons to be viable. So: at this time a Chrysler 20 horse is not rebuildable.

HOWEVER: If the engine will run while you squeeze the primer bulb, you do NOT need a rebuild. It is probably not the carb, so you are left with the fuel pump--put in a new diaphragm and examine the check valves to be certain they are opening and sealing correctly. Also check lines between the primer bulb and fuel pump, especially the quick connect female fitting (if the engine has one). The Female fittings have an O ring inside them that does go bad and then, the engine will suck air. The O ring is a special size so you would need to look around a bit to find them. OR---simply replace with Merc or OMC fittings. Check the female fitting for a partial clog.

 

[grizzrider09]

Re: Need An Experts Opinion on 1974 20hp Chrysler

Back to square one here, After taking this motor to the mechanic he let it sit around for about 6 months and he never did anything with it claiming he couldnt get parts. So I went and picked it up and gave him a piece of my mind. Now I still have the same problem but I noticed that the fuel line from the pump to the carb was rotten so I replaced with a clear one I had on another motor. I noticed when I squezed the bulb gas flowed to the carb and when i let off the bulb it seemed like it went back up to the fuel pump. I just replaced this fuel pump 6 months ago. Is this normal? Im lost as to what I need to do.

 

[jerryjerry05]

Re: Need An Experts Opinion on 1974 20hp Chrysler

Start with a compression/spark test.
If they are good then you can get it running!!!
Start with a carb cleaning, then replace the fuel pump diphram.
Replace ALL the hoses and any inline connectors.
Profile?? Location?? You might be close to someone who can help?

 

[grizzrider09]

Re: Need An Experts Opinion on 1974 20hp Chrysler

jerry, I have checked the compression and both cylinders are 105-104. I cleaned the carb and it has a new fuel pump diaphram. All thats left is replacing the hoses and connections. I am in Forest Mississippi so if you know of a good mechanic I would be happy to go see em. Thanks,

 

[pnwboat]

Re: Need An Experts Opinion on 1974 20hp Chrysler

I would suspect like Frank mentioned above that one of the check valves in the fuel pump is stuck. Not sure if your fuel pump is the same as in the diagram below, but they are replaceable. Item number 4. There are 3 of them in this particular pump. The check valves are one way valves that will only allow the fuel to flow towards the carburetor. If one is stuck open or closed, the fuel pump will not work.

Mercury, Mercruiser, Force, etc. - FUEL PUMP - 25 H.P.

 

[grizzrider09]

Re: Need An Experts Opinion on 1974 20hp Chrysler

Well guys I finally got it running and it only took about 5 min to fix. I talked to Franz at Franzmarine and he told me to put the hose from the tank straight to the fuel pump and it cranked and ran like that for a solid hour. So my problem was actually the fuel line connectors which were new. I swapped it over to a johnson style connect and everything is good to go except i need to clean the carb and put new plugs in. Thanks for all your help guys

 

[Frank Acampora]

Re: Need An Experts Opinion on 1974 20hp Chrysler

Ahh! Back on Sept 30, did I not say to check the quick-connect fittings and possibly replace them with OMC or Mercury connectors?

 

[grizzrider09]

Re: Need An Experts Opinion on 1974 20hp Chrysler

Ha, Frank indeed you did. I guess the only reason I didnt do that is because I had just bought new ones back in the summer and thought there was no way that could be it. I was wrong and sorry for not taking your advice earlier. Now on to new problems. I pulled the carb and cleaned it just to be safe and it ran like a top. A few ours later I load it on the boat and get in the lake and it wont crank. I had to spray gas in the carb to get it to crank and once cranked it only agrivated me further. First it would go dead when it was not choked. Ran it on choke for a good 15 min and it acted right so I let off the choke and rev it up everything is fine till i put it in gear and then it tried to go dead. Pull the choke back out and it runs in gear but has NO Power at all. Put it in nuetral it runs like normal and revs high. Back in gear same thing no power have to run on choke. Im lost and sick and tired of messing with this thing. You think it could be bad gas Im running and its clogging my high speed jet up?

 

[Nordin]

Re: Need An Experts Opinion on 1974 20hp Chrysler

You say you have clean the carb. Have you set it up right after that?
The float should be paralell with the casting, idlemixtureneedle should be about 1 1/4 turn out from lightly seated.
Then you may "fine tune" it, normaly it will be at 1-1 1/2 out of lightly seated.
Then you have the throttle pickup point.
At the throttlecam there is a mark, when the roller touch and is just at the cammark the throttlebutterfly shall start to move. If not, adjust the rollerfollower with the screw at left of carb.

Those 20Hp Chrysler are really nice engines. Runs smooth and with low noice. They are simple to work on.
Think I have three or four of them and have own more then ten.

 

[Nordin]

Re: Need An Experts Opinion on 1974 20hp Chrysler

You say you have clean the carb. Have you set it up right after that?
The float should be paralell with the casting, idlemixtureneedle should be about 1 1/4 turn out from lightly seated.
Then you may "fine tune" it, normaly it will be at 1-1 1/2 out of lightly seated.
Then you have the throttle pickup point.
At the throttlecam there is a mark, when the roller touch and is just at the cammark the throttlebutterfly shall start to move. If not, adjust the rollerfollower with the screw at left of carb.

Those 20Hp Chrysler are really nice engines. Runs smooth and with low noice. They are simple to work on.
Think I have three or four of them and have own more then ten.

 

[grizzrider09]

Re: Need An Experts Opinion on 1974 20hp Chrysler

Thanks for the advice man. I took the carb back off and let it soak for about three hours in carb cleaner then blew it dry with the air compressor. Put it back on with new gas in the tank and adjusted all that could be adjusted and its running fine again. I assume there may have been water in the tank or trash in the jets.