Chrysler 140 HP Power Issue

[Ed_1976]

I have a 1981 140 hp Chrysler outboard and when I give it full power it only gets up to 3000 rpm and the bow goes up in the air and it bogs down. After a few seconds sometimes minutes it'll plain out and go with no issues. I know things like this are fuel related but could use some help pin pointing it. Thank you.

Ed

 

[jerryjerry05]

Do a compression test then spark test each cyl.
Those OK?
Check the burn on each plug.
Check the fuel pump diaphragm.

 

[Ed_1976]

I ordered all new parts for the fuel pumps and will be replacing them as soon as they come in. The first time I took this boat out it had brand new plugs in it. I will do a compression check as well. Jerry, I also read that it could be a blocked fuel vent on my gas tank. Is that a possibility?

 

[jerryjerry05]

When the vent is blocked: it usually dies slowly and then
will get better after setting and then die again.

Wasps/bees can get in the vent hose and make nests a
and block the air.

 

[Ed_1976]

Jerry,

I see a 135hp Chrysler on ebay, could I use that as a parts motor for my Chrysler 140hp?

 

[Nordin]

Yes you can use the 135Hp as spare.
Depending on the year of the 135Hp the gear case and the ignition system can be different.
I suppose your 140Hp has a 1 piece gear case and Prestolite ignition system.
The 135Hp may have 2 piece gear case and Motorola Magna Power ignition system with a belt driven distributor.

 

[jerryjerry05]

When asking specific questions??
Always include the year, model and serial#
Makes answering question much easier.

While the 135 and 140 are close in HP
They can be worlds apart when it comes to ignition
and gear boxes(Nordin)

 

[Ed_1976]

Ok Jerry here is what I had:

1. The fuel diaphragms were old and wrinkled and only had the diaphragms, there was no gasket installed. So I rebuilt both fuel pumps.

2. Did a compression check on all cylinders and got 100, 120, 105, and 120.

3. Changed all spark plugs, the only one that seemed fouled was the #4.

4. Adjusted idle mixture.

Took the boat out Sunday and when I gave it WOT, the bow went up in the air for 3-5 second and then leaned into the wind and ran great the whole day. I understand this engine is 40 years old and will not perform like a brand new one. I'll let you know how it did when I take it out again this weekend.

 

[jerryjerry05]

Wrong about the performance!!
The Chryslers were one of the ones that didn't get tired
as they got older.
Had a pair of 88/85hp Forces(Chryslers) that ran as good at 28
as they did new.
The only reason I changed them was the salt water destroyed the
mid section and they ended up bending the softer parts.