1976 Chrsler 135hp

[matshallard]

Hi All,

I would really appreciate any assistance needed for my 1976 Chrysler 135hp engine. I'm reasonably new to boating and have an issue with fuel mixture (probably a bacic one). I currently run the mixture at 50:1, a few times now I have got the mixture wrong and the engine doesnt start or it does start but as soon as you put the engine in nutural to engage the gear it stalls, or even when the revs are low it stalls. On previous occasions I have added more petrol and it started working fine.
My last few trips out I have had the fuel mixture right at 50:1 but it seems to be doing the same thing and stalling when you drop the revs and go to put the engine in nutural?
Can anyone help me with a reason why? Is the fuel mixture wrong at 50:1? Should this be causing it to stall at low revs or nurural?
Many thanks
Mat

 

[IamCanadian]

Re: 1976 Chrsler 135hp

How wrong was the mix? An outboard will run with the mix between 25:1 and 50:1. It sounds more like the carbs may be dirty or out of sync, Maybe he fuel pump or it could also be a timing issue. Have you checked the compression? Have you ever mixed it over 50:1? like closer to 100:1?

You really need to be sure you do have the right oil mix and have no doubt about it before you even start a 2 stroke.

50:1 is correct for that motor.

 

[jerryjerry05]

Re: 1976 Chrsler 135hp

Like Iam suggests do a compression test.
If you ran it low and it scorched a piston it can hurt the compression.
Post the results.Any difference,don't run it.Till you remove the head and check the cylinders.
What's the rpm's at idle in gear in the water? They should be about 750-800
On the hose.about 1150-1200rpm.s

You say "petrol" so I guess your not in Alabama,maybe Africa? Fill out the profile.
Location? You might be close to someone who can help?

 

[Frank Acampora]

Re: 1976 Chrsler 135hp

The fuel mixture is correct at 50-1 but there is a bit of leeway so you don't need to be anal about getting the correct mix. I usually add 1 pint oil to 6 gallons gasoline for a 48-1 mix. If you are metric, 500 ml to 24 liters will give the same result and you don't need to think about it.

Before you do anything else, remove all four sparkplugs and either clean them or replace them. These surface gap plugs tend to foul easy. The first symptom is difficulty starting, or stalling in neutral and when you put the engine in gear. SO: Clean the plugs then check the idle speed.

Idle speed can be reset (if necessary) using the idle stop screw located on the timing tower at the carb link. It is a screw held tight by a locknut. Loosen the locknut and turn the screw in about 1/2 turn at a time. Blip the engine then come back to neutral and check idle speed. Do this until it is correct.

The correct idle speed will give a "clunk" when the engine is put into gear. Too high and the clunk will be very loud or the lower unit may make grinding/crashing noises. The boat may move too fast. Correct idle speed will move the boat slowly through the water.

Watch the end of the video in my post Cougar Cub powered with a Chrysler 50. You will see the correct idle speed along with the correct water speed while I am docking. Note that I control the speed by putting the engine in and out of gear as needed.

 

[matshallard]

Re: 1976 Chrsler 135hp

Hi Guys I wrote a big reply last week but for some reason it has not appeared. I'm in Sudney Australia. Thanks for all your assistance. I will take them all into account and try and work out what the issue is. Being that the mixture then seems ok I'll be cleaning the carbs this weekend (not sure the best way to do that but I'll youtube it)
Thanks again for your help

 

[jerryjerry05]

Re: 1976 Chrsler 135hp

Cleaning the carbs: don't use a carb soak.
Some of the Chr/Force has rubber o-rings in the needle/seat.
The soak will expand the rubber and it can swell closed.
No gas will pass the o-ring.
It can take a week for the swelling to go down.
I use Dawn dishwashing liquid. Or the purple stuff from Auto Zone(guessing no AZ in AU) .
Then rince with water and blow dry.
Any spray lubes can/will leave a residue and make the parts sticky.
The gas/oil leaves residue(after time)and you don't wanna add anymore sticky.