4hp Chrysler

carleton

Seaman Apprentice
Joined
Jun 30, 2012
Messages
34
I am having a problem with this 4hp Chrysler model 42H79F.I have gas and a spark but it want hit a lick.Where should I look for where the problem could be?
Thank you
Jack
 

wickware

Lieutenant
Joined
Jun 20, 2009
Messages
1,286
Re: 4hp Chrysler

Pull the plug and check for compression. With a gauge it should be close to 90-100 in 3-4 pulls IMO. Without a gauge you s/n be able to hold the compression in with your thumb or finger. It takes Spark/Fuel/Compression To Fire!!
 

carleton

Seaman Apprentice
Joined
Jun 30, 2012
Messages
34
Re: 4hp Chrysler

Pull the plug and check for compression. With a gauge it should be close to 90-100 in 3-4 pulls IMO. Without a gauge you s/n be able to hold the compression in with your thumb or finger. It takes Spark/Fuel/Compression To Fire!!

Compression is good.What am I missing?
carleton
 

IamCanadian

Petty Officer 3rd Class
Joined
Oct 22, 2012
Messages
78
Re: 4hp Chrysler

is the spark strong and blue? is the timing set right?
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 4hp Chrysler

Assuming it is the two cylinder, water cooled 4: Are the plug wires on the correct cylinders? If they are switched, it will spark 180 degrees out of timing. It will not fire and will not even backfire. It will just sound like it is not getting either spark or fuel.
 

wickware

Lieutenant
Joined
Jun 20, 2009
Messages
1,286
Re: 4hp Chrysler

What year model related to Mag or electronic ignition?
Have you changed the plug?
If Mag Sys, have you checked the point?s condition?
When did it last run with good performance?
Do you have the history of the past that led to this matter?
 

carleton

Seaman Apprentice
Joined
Jun 30, 2012
Messages
34
Re: 4hp Chrysler

I bought it and it would run very ruff. I put a new carb. and a new set of points on.Has not started since.
 

wickware

Lieutenant
Joined
Jun 20, 2009
Messages
1,286
Re: 4hp Chrysler

Please post a pic of the new set on points you installed (up close but showing all the inside of the magneto system. Please post your steps and specs of setting the points. Such as: .030 at TDC which is only an example vs correct. No harm intended in this info vs trying to help you. Attached is my 1970 35 HP Chrysler Mag sys If You Have Not Seen It Before. LOL! I feel we'll have this Monster running soon.
 

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  • 1970, 35 HP Chrysler's Magneto System.JPG
    1970, 35 HP Chrysler's Magneto System.JPG
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