1972 Chrysler 45hp

[ginnywinnieb]

I have a 1972 Chrysler 45 that was running fine until the last time I took her out. I could not get her to fire up and have not been able to get her to fire up since. I have replaced the spark plugs and now all she will do is back fire really bad. My Dad and I took her apart over the summer and cleaned her out completely. She was running well except for a little hesitation when open to full throtle. <br />Any help you can give me will be appreciated.

 

[eurolarva]

Re: 1972 Chrysler 45hp

So the motor was working fine before you took it apart? If so what is it you took apart? First check to see if you hooked the plug wires to the correct plugs. Also post your model number. It should be located under the carb somewhere.

 

[ginnywinnieb]

Re: 1972 Chrysler 45hp

Actually, the motor was taken apart and cleaned and all the good stuff when my dad bought me the boat last summer. It was running fine then except for a little hesitation when open to full throttle. <br />She put me down the last time I took her out and have not been able to get her started since. I will go now and get the model number for you.

 

[ginnywinnieb]

Re: 1972 Chrysler 45hp

The model number is 5591 and the serial number is 3118

 

[eurolarva]

Re: 1972 Chrysler 45hp

If 5591 is the correct number the motor is a 1969 55 HP chrysler. It is possible that the motor was a 55 Hp and a different cowling was put on the motor. Chrysler 45 and 55 are real similar and I believe a 45 cowling will fit on a 55.<br /><br />The last time you were out did the motor run fine (not including the hesitation) then just die on you? If so I am thinking your impeller in your water pump crapped out and you overheated. When this happens the pistons expand from being overheated and stop moving. After about an hour the motor cools off and the pistons go back to their original size and the motor will normally start up again. What may have happened is the torque on the flywheel may have sheared the flywheel key. This would cause the backfire you are experiencing. <br /><br />The hesitation sounds like an over rich carb which can be adjusted by the adjustment screw on the face of the carburator. About a 1/8 turn clockwise will lean it out a bit however chryslers are better running a bit rich.

 

[ginnywinnieb]

Re: 1972 Chrysler 45hp

The cowling was changed when we worked on it this summer due to the fact that it fell over and broke. We had the 55 for spare parts and used the cowling off of it. It is a 1972 45hp, I saved the model number plate, I just have to locate it.<br />The last time that I used the boat, she cranked just fine and ran fine all day long. The last time I killed the motor to fish, when I went to crank it again, she would not start. I took the plugs out and cleaned them just in case I may have flooded it, but it did not help.<br />I just went out and tried to crank with the top plug in only and she backfired like crazy, but with the bottom plug only in she would not backfire.

 

[eurolarva]

Re: 1972 Chrysler 45hp

Test for spark on both plugs. Remove the plugs from the cylinders and use a wire or something to ground the threads of the plugs to motor ground. Make sure the plug wires are connected to the plugs. It is best to do this in a dark area. Hae someone else engage the atarter while you watch the plugs. Are you getting a good blue spark on both plugs.

Chrysler calls for a champion plug that is no longer availible. The best plugs availible are champion L82C plugs. NAPA or any car dealer should sell these for about 2 bucks each. Maybe get a couple of these and try them.

If spark is good try spraying a gas oil mixture into the carb, choke it and try sarting it again. Also does the backfire come out the carb or out the exhaust?

If you have yahoo messenger I am online right now.

 

[ginnywinnieb]

Re: 1972 Chrysler 45hp

The plugs that you mentioned are the ones that I just replaced the old ones with. It backfires out of the exhaust. I apologize, but I do not have yahoo messenger.

 

[ginnywinnieb]

Re: 1972 Chrysler 45hp

Do you have any information on someone who may work on these motors in the Dallas Ft Worth area?

 

[eurolarva]

Re: 1972 Chrysler 45hp

Because of the age of chryslers and the lack of parts finding a mechanic for that motor is tough. Alot of us have resorted to buying service manuals and learning to do most of the work needed to keep them running. The first two things your mechanic should do for you is test compression and spark. My service manual says that backfiring out the exhaust is timing related. Ususally the timing once set does not move and that is why I am thinking the flywheel key. Good luck