1989 Force 150 hp question.

tigfit

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If I want to take a compression test of the cylinders is it ok to pull the kill safety link thats by the key so that I won't have to ground all the spark plug leads. Also is there any way of changing the spark plug leads on a presto lite electronic CD system? I Am trying to figure out why this engine runs rough at idle and the rpm's fluctuate 300 to 400 rpms at idle ! Thanks!
 
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jerryjerry05

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No the plug leads are built into the coil.
You should be able to see if the leads are leaking.
​I use heat shrink and liquid electric tape to stop the arcing.

Yes you can disconnect the kill switch to jump the motor.
If you jump it at the solenoid you shouldn't have a problem.

The 3-400 surge. reset the carb air screw.
​Turn them in slowly and record the amount of turns and post it.
Then turn them out 1 and 1/2 turns.
Then adjust from there.
​The top 3 posts have some good info.
 

tigfit

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I had already removed the carburetors and cleaned them although they seemed clean. I put new bowl gaskets in and set the idle needles one tun out to start with but it seemed to run the same way as before I cleaned carbs with rpm's fluctuating up and down at about 1000 rpm if I go up to 2000rpm it seems to run smooth! I also put new fuel pumps diaphragm in .I followed the Frank Acampora video on you tube everything but timing (need to get a timing light) and I can't believe how the idle became smooth! Thanks for your help.
 
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tigfit

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One question I still have is what is the purpose of the black roller with offset screw it can't just be for a marker to set cam position is it? Seems to turn easy even after tightening it. Thanks Again!
 

Jiggz

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The purpose of the black roller with offset screw is to adjust the pick up point for the carbs' throttle opening in relation with the cam. Which in turn is tied to the timing tower that is controlled by the control cable. The timing tower controls both the advancing of the timing (through the trigger plate) and also the opening of the carbs throttle (through the cam and roller and tie bar for multiple carbs). And both movement should be in synch.

At mechanical zero, i.e. carb throttles fully closed, idle screw backed off the engine block, and timing at zero, the black roller should be in contact with the cam at its hash mark. If not, then by loosening the locknut on the roller, you can adjust the eccentric screw to make it so. Usually, the slot of the eccentric screw will also be in line with the cam's marking.

Of course, as soon as you set your idle speed, the cam's marking will be a little bit lower than the roller, indicating the carbs' throttles are slightly open hence also the timing.
 

tigfit

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Thank you for your post. Even though I watched a few video's on you tube I wondered why the eccentric screw on roller which you described well the reason for it. Thanks Again!
 

Degrath

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I have a 1980 Chrysler 55hp with prestolite ignition and had an issue with both coils where the metal contact inside spark blug boots broke and what I did was found some mercury coil wires and pulled the boots off the ends. There was a kinda spring coil with a longer contact wire in the boot that I stabbed thru the metal collar on the wire that remained from the old connector then pulled the boots back over the new connection and hit it with liquid electrical tape to seal around it. Both my coils now work and the engine runs and idles nice and smooth.

This is not a picture of my wire but I uploaded it to show the spring deal (no Idea what its called) I pulled from the Mercury coil wires.

bad-connecton-at-plug-wire.jpg
 

Degrath

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it was the closest thing I could find to the thing I was trying to describe.
my Chrysler wires were crimped on the end with a folded over metal tab that wrapped around the plug.
 
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tigfit

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This 1989 Force 150hp is driving me crazy!! Last night primed the bulb hit the primer on the key and it fired right up! This morning did the same thing and nothing just keeps turning no fire. ?????
 

Jiggz

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You need to seriously troubleshoot and diagnose the source of the problem. Since it fired the night before and today is just cranking over without firing. Check the easy ones first.

FUEL. Is fuel getting into the carbs or even better to the cylinder. Pull one of the spark plugs and check the tip. Is it wet with fuel? If fuel is getting into the cylinder, yes it should be wet if it hasn't fired.

ELECTRICAL. If there's fuel in the cylinder then you need to check if the spark plugs are firing at all or have sparks. The best way is to have an inline spark tester which you can get at an auto parts store for less than $5

If there is fuel and spark, make sure you did not flood the carbs. If it was flooded due to frequent choking, you will need to dry the spark plugs. But before doing so you need to clear the flood by cranking it over (without choking) for about 5~8 sec for at least three times with the throttles in neutral (NO FAST IDLE).

If you have not done so, install a clear fuel filter between the fuel pump outlet and the carbs inlet. This is more for troubleshooting rather than fuel filtering. Finally, when starting from cold, make sure you follow proper starting procedures, i.e. prime, put throttles in fast idle, choke and crank it over. Do not crank more than 5~8 seconds when choke is engaged nor are you supposed to engage the choke unit more than 2X at the most. As soon as it "coughs" stop and re-start without the choke.
 

tigfit

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Thanks Jiggz ! I will get back on my results probably Monday. I read on one of the post about the wires on the stator & trigger and cdi units that sometimes the connectors corrode and don't make contact under shrink tube! Found one wire today that when I grabbed it fell apart in the shrink tube. So I think maybe I should check all terminations on block.
 

jerryjerry05

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You say no fire? no spark??

​The trigger leads, the connectors all need to be replaced.
Then do the ones on the packs.
 

tigfit

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Must have a carb problem 3rd cylinder down of the 5 when I pulled the spark plug had lots of gas run out of cylinder other four were just a little wet. Checked choke but didn't see any gas going through it when I pump primer bulb. Probably time to replace all needles and seats after 27 years.
 

jerryjerry05

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#3 and #4 run the fuel pumps.
​Excess fuel in either cyl. could be the diaphragm is bad and fuel getting in the cyl?????

Does the ball get hard when pumping??
 

Jiggz

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Open and inspect the fuel pump diaphragm. It's really very easy. If there's that much fuel into the cylinder, it's most likely a torn diaphragm.
 

tigfit

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I had just replaced them 6 months ago. I was wondering if I were to pinch of or plug fuel line to carbs and pump up primer bulb and then get gas in cylinder it would tell me for sure I have a bad pump?
 

jerryjerry05

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Yes that test would.
Post your results.

The 10 pumps might not be a problem.
You have a long way to draw gas from and push gas through 2 pumps.
 

tigfit

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Yes it is a torn diaphragm. Let you know how it goes when I get parts. Wonder how it ruptured so fast. must have been defective. Thanks!
 
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