My boat run slowly. 120HP,2.5L,1989

[kenny nunez]

If the rotor shaft bushing in the distributor is worn out that will cause the timing and dwell to continually go out of range. That could be what caused the spark plug damage. Also if the pins that hold the fly weights under the breaker plate are allowing the timing to over advance.

 

[liusigou]

I replaced the gasket of distributor which led to the timing off. Later I set the timing by myself according to following viedo. I am not sure if it is correct or not.

 

[alldodge]

should work

 

[liusigou]

Can anybody confirm my timing setting correct or not? I stopped at the multi-meter changed from 0.3 to 6.7.

Before doing the timing setting, I have put the yellow line at the 0 postion(seen the first pict).

My multi-meter does not have the function of beep. The max value of multi-meters is 6.7 even there is a obvious gap. I should be very big value. So I am confused.
View attachment PXL_20230627_203153032.TS.mp4

 

[alldodge]

Guess I have to back track a bit.
I didn't watch the entire vid in post 22 and assumed he was showing how they open and close. Also how gap was set, but turns out he was just getting it real close to start.

Doing it his way will get the motor to run but timing can be anywhere from on spec to a bit off.

Its best to use feeler gauges and then check with dwell meter. Timing is set using a timing light. Should be able to borrow both from a local auto parts place

 

[liusigou]

I did another timing setting by multi-meters with beep function. It continued to beep even there is a obvious gap. So I stopped when it changed from 0.3 to 6.9 and mounted the cap and connected the line to spark plug. also I started the motor. it worked.

I will do a water testing and check it run smoothy or not.

What reason caused the third cylinder drop from 120 to 100 for the pressure. I concerned another cylinder will be damaged again.

 

[liusigou]

Should I replace this because it is not complete open.

 

[Scott Danforth]

I did another timing setting by multi-meters with beep function. It continued to beep even there is a obvious gap. So I stopped when it changed from 0.3 to 6.9 and mounted the cap and connected the line to spark plug. also I started the motor. it worked.

I will do a water testing and check it run smoothy or not.

What reason caused the third cylinder drop from 120 to 100 for the pressure. I concerned another cylinder will be damaged again.

stop.

get a dwell meter (borrow from your local auto parts store)

set dwell to 30 degrees.

if dwell doesnt read, you have a points or condenser issue.

 

[alldodge]

Agree with Scott
and do replace the points, condensor, cap, rotor

 

[liusigou]

I have ordered the distributor tune up kit in Amazon. it will be deliveryed in Jun 30.

 

[liusigou]

So sad for the third cylinder. Its' pressure drop from 120 last year to 100 this year. What reason caused the dropping?

 

[liusigou]

I have got my new ignition tune up kit and I have also installed it. But the old one should work

 

[dubs283]

But the old one should work

Based on previous pics/info posted it won't. Maybe 50/50

Did your properly installed new ignition system components get the motor running well?

 

[liusigou]

Based on previous pics/info posted it won't. Maybe 50/50

Did your properly installed new ignition system components get the motor running well?

The engine fires very well with the new spark plug and the new ignition system components. I also set the correct timing. But boat still run only with the maximum speed of less than 10mph. and the third cylinder pressure is 110(cylinder is warm) and 100(cold). How can I fix the issue of slow?

 

[dubs283]

With the ignition system now sound I would investigate fuel supply

 

[liusigou]

With the ignition system now sound I would investigate fuel sup

Could you please guide me do the investigation?

 

[dubs283]

Not very easily over the internet

Best advice I can provide is to start at one end of the fuel supply and work the opposite direction until the problem is located

 

[liusigou]

Not very easily over the internet

Best advice I can provide is to start at one end of the fuel supply and work the opposite direction until the problem is located

How?

 

[dubs283]

How?

Pick one end of the fuel system. Either carburetor or fuel fill/vent system

Start at the chosen end and begin inspection of components and fuel present. Continue towards the other end with proper inspection until the problem is located.

Repair as necessary

 

[alldodge]

What reason caused the third cylinder drop from 120 to 100 for the pressure. I concerned another cylinder will be damaged again.

Your entire motor is tired. If 100 is accurate then the motor is basically running on 3 cylinders. The 100 cylinder is working but not much power is coming from it. The other 3 are tired also with 120 and then add in blow by and if motor was mine I would rebuild it