1985 120hp bogging down at higher speeds

[Joe Reeves]

Re: 1985 120hp bogging down at higher speeds

Since you've switched coils to no avail...... that is, the problem DID NOT follow the coil but rather stayed faulty on number one cylinder, I would assume that the spark problem is either a poor connection at one of the powerpack connectors (coil or timer base etc) OR a faulty powerpack.

The compression difference, if you're sure that the pistons and rings are okay, suspect the head gasket. Head bolt torque is 18 to 20 foot pounds, tightened in the following sequence.

9...10
5....6
1....2
4....3
8....7

 

[61fish]

Re: 1985 120hp bogging down at higher speeds

Again Thanks for all the input. I am going to replace the Head gasket and recheck the compression. I read somewhere that spraying some WD 40 in the cylinder will help compression if it may be dry. That cylinder seemed less oily than the other.

I will replace the bulb and check all conections in regard to the powerepack. From there I will do some more reading on checking out the powerpack.

As Charlie B suggested, I woill check the flow rate of the pump.

Are there any tips in checking this out out, Will I need any special meters? I have an older meter I used to set the points in my older cars. It has amps/volts/tach.

Again Thanks

 

[61fish]

Re: 1985 120hp bogging down at higher speeds

Well I finally have had a chance to check things out a bit further.
I have replaced the head gasket and rechecked compression compression now up to 112, 120 122 and 125.
I havent yet checked the flow rate on the pump as I am still working on NO spark to #1. I did fully charge the battery and check spark again, still no spark on #1
I did secure a multimeter and begin to learn how to use it. I started with CDI trouble shooting guide and checked the trigger resistance. I have no idea what this is or means but white to Purple/ green/ and pink were all between 27 and 28. From white to blue was 32.6. The guide said they should all be between 35-55. What does this mean?

Also from another thread, Joe Reeves said in regards to the stator;

<<<<<<<<(A weak failing stator could provide exellent spark when cold but erratic spark when hot, just exactly how erratic is unpredictable. A failed stator, completely failed, would result in no spark.

Check all of the wiring connections at the pins/sockets..... wires broken away from the pins/sockets, pins or sockets pushed slightly back into the rubber plugs resulting in poor connections, etc. This includes the connections between the timer base and the powerpack, and between the powerpack and the coils.

To check the powerpack circuitry to that one cylinder..... temporarily switch the timer base sensor lead that connects to the power pack, one that you know is firing some other coil, from that location to the location that should fire that non firing coil (without changing the coil wire to powerpack locations).

If the coil will now fire, the powerpack is okay and the problem would be either in the timer base to powerpack connector, OR the timer base, OR possibly the cranking speed of the engine.

The engine must crank over at least 300 rpm in order for the ignition to be energized.)>>>>>>>>

I wanted to check the circuitry of the power pack to the one cylinder that will not fire as suggested. What color wires are the timer base sensor leads? I only see two plug-ins to the pack from under the flywheel...Am I missing something here??

I appreciate all the input I recieve.
Thanks, Bill

 

[61fish]

Re: 1985 120hp bogging down at higher speeds

Well I am finally back to bring closer to this situation. After a considerable amount of reading, I decided to head out to the lake with a timing light, and different hose /bulb combo. I hooked up the timing light to the plug wich had not been showing intermitent if any spark. Cranked the engine, had little to no spark at first then started and it did not miss a beat. Repeated on all cylinders with good spark. Set it back to number 1 cylinder and off we went. After a few minuted at 3/4 to wot it started to cough and bog down again but spark was not the issue, it kept flashing just fine. I repeated on all cylinders just to make sure and It never lost a cylinder due to no spark. At about the third time I had my wife pump the bulb but she said it was very firm already. Joe Reeves had mentioned earlier that it should be soft as fuel is flowing. I swaped out hose/bulb and off we went. After almost 3-4 miles, the boat did not miss a beat, I believe it was healed!!!
I am still going to de-carb and recheck compression later but it appears all systems are a go. I sincerely appreciate this site and all the efforts of the experts who must spend hours sorting through the threads.
Many Many Thanks, Bill