1975 Chrysler 459he 45 hp running issue

[jimbass55]

Just bought a boat with a 45 hp Chrysler which was not running. I have installed a starter, solenoid, carb kit, fuel pump kit, new gas tank, new fuel line and bulb, new battery, fresh fuel, lower unit lube, impellar, and spark plugs. The motor fires off everytime while being choked, and will run for a second but dies. I can fire it right back up but same thing. It will die soon whether choke is on or off. I can convince it to run for a few seconds with some heavy throttle but it revs up and still dies. I feel like it is a carb issue but this novice is scratching his head. Fuel can be seen dripping from carb out of choke shutter area. I have been reading on here but this is my first post. Thanks in advance for any pointers. By the way compression is 95 and 107.

 

[jerryjerry05]

Re: 1975 Chrysler 459he 45 hp running issue

Get another guage and try the compression again.
Those #s seem way low.
With a good guage it should be above 145.

 

[wickware]

Re: 1975 Chrysler 459he 45 hp running issue

Check for carb flooding and too rich carb adjustment.

1. Is the carb float adjusted and stopping gas flow?
2. How far out is the carb?s needle adjusted from a light seat (per your manual or ref)?

 

[jimbass55]

Re: 1975 Chrysler 459he 45 hp running issue

I was thinking the float today...i have learned alot...this is my first dig into any motor. 145 compression? I thought guys bragged about 125. I am a newbie. I bought a spark tester today as well. I will get to it Sunday and see what happens. Thanks.

 

[jerryjerry05]

Re: 1975 Chrysler 459he 45 hp running issue

Yea 145 is a good # Mine are at 150-155#
Some are at 165#???
It sounds like the needle/seat might be clogged??
If the carbs are really corroded.I clean my carbs with any carb cleaner.Parts too.
Then I use Dawn dishwashing liquid to get all the oil, cleaner, any residue.
Then I blow dry the parts.
Letting them air dry completly.
The rubber on the end of the needle can swell and deform from the carb cleaners,so give it a day to get back to normal size..
Then when it's all dry and ready to re-assemble, I put them together dry.
No WD or sillycone spray.
If the float isin't set right it can do this too.

 

[jimbass55]

Re: 1975 Chrysler 459he 45 hp running issue

ok...adjusted float and idle screw...same thing...when I hold my finger over this hole it runs. Is it supposed to be plugged?

 

[jimbass55]

Re: 1975 Chrysler 459he 45 hp running issue

btw...i ordered a used carburetor off ebay that has the choke solenoid...this motor was missing it and someone installed a manual choke.

 

[wickware]

Re: 1975 Chrysler 459he 45 hp running issue

Is your finger over the carb?s adjustment needle?s port or carb?s throat? ?Guessing?!

1. If it?s adjustment, I feel the adjustment could be "way" off. What is the setting from seat?

2. If it?s over carb?s throat or needle port, it could be sucking air at another source.

3. How well is it running, accelerating or just idling?

4. Is it time to check the reed valves and what else Pros. I h/n experienced this prob.

 

[jerryjerry05]

Re: 1975 Chrysler 459he 45 hp running issue

That's the air screw, is it empty?
If so you need a needle valve.
If none needed it needs to be set right, turn in gently untill it bttoms and then out 1 full turn.
Then re-adjust after it's started and warm.
Running, turn in slowly till it stalls, kicks,bucks,stutters. Then back out 1/2 turn.
Idle should be about 1200 in the drive, 750-800 in gear in the water.

 

[jimbass55]

Re: 1975 Chrysler 459he 45 hp running issue

It is the small hole under my index finger. It attaches to the small tube inside the bowl.

 

[dropbear68]

Re: 1975 Chrysler 459he 45 hp running issue

Id be giving a look to the reed valve, could be cracked or broken, carbys can be a real problem on any motor even a car thats been left dry for many years, you never know how many weekend mechanics have had there input in it either, you sound like youve given it a good go over, start from scratch and do the old process of elimination, sooner or later you will find the culprit.

 

[jimbass55]

Re: 1975 Chrysler 459he 45 hp running issue

It was the guilty hole...I gues the weld or plug came out and it was sucking air making it run too lean. I installed the new (used) carb and she fired up. I couldn't get everything adjusted cause I had to shut it down but I am happy for now.

 

[jerryjerry05]

Re: 1975 Chrysler 459he 45 hp running issue



Was looking under the thumb.yes the hole should be blocked.
Some rebuild kits have the welch plugs in them.
When your done installing the plugs, use Indian Shelack to paint over the plug.It's gasoline proof.

 

[jimbass55]

Re: 1975 Chrysler 459he 45 hp running issue

Now she runs great. I took her out and no forward gear...new adventure I guess.

 

[wickware]

Re: 1975 Chrysler 459he 45 hp running issue

1. I see you had your shift rod disconnected changing the impeller.

2. Could you not have adjusted it between Forward and reverse?

3. Do you understand how to starting the coupling at both threads to center linkage?

4. Do you have reverse? Have you had forward before?

5. Have you tried disconnecting shift rod and shifting by hand directly at L/U rod?

6. Do you know any history of this motor?

 

[jimbass55]

Re: 1975 Chrysler 459he 45 hp running issue

I have zero history. I don't know if I had forward before. (just got it running) I do have reverse. I have been adjusting shift
rod.(still hoping that is the issue) It seems to work properly when just using lower shift rod but I have not ran it unattached for fear of damage....is it okay to do it? that would answer all the questions. thanks...

 

[wickware]

Re: 1975 Chrysler 459he 45 hp running issue

I would not run it not attached unless the Pros say that is safe. It sounds like it could be an adjust matter. Try and get the ?Monster? centered. Also consider if it could be a shift control box or cable matter. Take your time and Goooood Luck!

 

[jimbass55]

Re: 1975 Chrysler 459he 45 hp running issue

I ran it this morning with cables detached and I do have fwd...it is just a linkage/timing issue (dont know if that is proper terms)...I have to replace lower unit seals then I will get it done. thanks

 

[rickryder]

Re: 1975 Chrysler 459he 45 hp running issue

If you need the oem service manual for that motor go to my 4shared account and download it ob2803 - Download - 4shared

 

[wickware]

Re: 1975 Chrysler 459he 45 hp running issue

I used these marks (attached) to Ref my coupling being centered in N between R & F. After the challenge and success, of centering the coupling. I found it simpler for me to use a longer bolt and nut to hold a window open on the LU. While I removed and replaced the shift rod cotter to eliminate readjusting.