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1991 Johnson 150hp Fast strike no longer starting

T

TMala

New member
I have been reading this forum substantially and read a wealth of knowledge pertaining to my engine and previous issues previous people have had, unfortunately I still can't figure out what is going on with this engine.

The engine is Model 150 GLEIS bought in March 2019 (new to me).

Boat from March to June was running OK, often sneezing out the exhaust and would shut down at idle but would quickly restart. This I figured was due to the fact that the boat had not had any service done to it for quite some time. So I performed the following

Bought OMC service manual
Replaced spark plugs with factory recommended plugs
Rebuilt all six carbs
Replaced cracked fitting on primer solenoid (the red valve was cracked and spewing gas when key pushed in)
Replaced gasket for vapor separator (I could see a gas leak in there when ball was pumped)
Performed a link and sync, replaced a missing sleeve on cam next to throttle
Changed water pump and new lower unit lube (don't think that would do anything?)

Boat started first crank on muffs, I thought I had fixed the sneeze. Boat is kept in slip so I put boat in water, as soon as it was in water it started sneezing as usual, not much really changed. Brought the boat to the slip and over the last week has gotten so bad engine will not start until after two minutes of cranking. I can keep engine going at about 1500 rpm but anything below that and it dies. Previously engine was running strong, great top end and WOT lots of power.

Here is what I know:
- engine is hard to start while tilted and easier to start when level
- sometimes it appears to run better with primer solenoid set to PRIME position
- When engine sneezes and dies, I can visible see the gas line on the right side running from vapor separator to right bank move back and forth as if under some type of pressure. I can not feel or see a sneeze come out of the carburetors but I can hear and almost see a sneeze come out of the exhaust.
-Some of the gaskets around the fuel bowls appear wet when I pump the ball, as if the gaskets could possibly be leaking or fuel bowls warped?
-On the top left carb, if I pump the ball fuel spills out into the air silencer, if I leave the solenoid primer on the "prime" position on the top left fuel spills out continuously into the air silencer.

I bought a compression tester today fearing the worse as I was pretty sure engine was cooked # in Lbs/ft: 94 95 98 85 91 91. The 85lbs is troubling me, I tested it twice (keep mind I can not warm up engine at this point it will not start so maybe not the most accurate readings)

I also used an inline spark tester to at least see if there was power going to each plug and there was.

I took the fuel hose off from the vapor separator to the right bank so I can visible see fuel being pumped, looked ok

I am at a loss! Any thoughts on what to do next? I have the OMC manual and been trying to follow everything by the book.
 
When I used the lisle inline spark tester each spark tested as a yellow/orange light in the tester. According to the instructions the tester mirrors what the spark should be in the engine (which I thought should be a solid blue). Not sure if this is something that could be contributing to the issue (low spark)

I also drained the gas from the carb bowls into a clear glass jar, there is some black particulate floating in the gas, not sure how it could get there past the inline filter and fuel/water seperator, another possible cause perhaps of no longer firing?
 
It is next to impossible to properly start and have a engine running normally when it is "tilted" ... Keep in mind that the cylinders are horizontal and you're trying to get the "liquid" mixture to run uphill!

You mentioned leaking carburetors... that'll require correcting.

Spark plugs should be Champion QL77JC4 plugs gaped at either .030 (long life) or .040 (super hot spark).

Spark must be checked with a air gap type tester whereas a 7/16" gap can be set. With all spark plugs removed in order to obtain the fastest rpm, the spark should jump that gap with a strong blue lightning like flame... a real SNAP! Does it?

Spark testers are available at most any auto parts store... or build the one at the end of this reply.
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When you rebuilt the carburetors, hopefully you noticed that the jets are marked with their sizes and they were returned to their original positions.

The "sneezing" is normally caused by a lean setting of the carburetors via the "Idle Air Bleed" jets.

NOTE that the idle jets as per their name measure "air" not fuel... SO... to richen the mixture, the ID of the jet would need to be "smaller".

Trouble shooting involves having the engine running at idle and sneezing as usual. Then stick a couple fingers into the carburetor throats, one at a time, acting as a manual choke. When the sneezing stops and the engine rpm increases somewhat... you've found the offending carburetor.

As mentioned above, in not so many words perhaps, the culprit is usually a wrong size jet... BUT...unless changed at one time, the engine probably ran properly at one time with that jet... With this in mind, when you find the offending carburetor, do not overlook a leaking gasket, O Ring,whatever that may be affecting that same cylinder.
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(Spark Tester - Home Made)
(J. Reeves)

You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:

..........X1..........X2

.................X..(grd)

..........X3..........X4

This can obviously be modified to a 6 or 8 cylinder setup tester.
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The correct plugs are QL78YC for a 60° motor. Has VRO been bypassed as you should not have any fuel flow till VRO clicks? What color are the gaskets behind intake manifold? If black they need changed as TSB on this. Need to fix carb flooding and go thru carbs, plus the sync and link may be off as this will cause sneezing too.
 
Race: as I was rebuilding the carbs I did not check each bowl for warpage, this will be something I do next as I thought I noticed fuel leaking out of the bowl on two carbs.

Joe: I did not know that about engine tilt, makes sense! We had low water one morning and it would not start. I will try to find a proper spark tester or build what you mentioned. Should I be concerned about timing at all here? I think you produce a cool ez timer is that something I should be looking into?


Bullet the plugs I recently put in are QL77jC4 as per the omc service manual, the manual is old. Should I be using different plugs? The plugs I took out were a different number, I thought maybe the previous owner screwed up maybe I screwed up? The color of the gasket I think was orange. The vro is bypassed I do not remember hearing a click although sometimes if I pump the ball real hard I can maybe hear a click? I will perform another link and sync after going through crabs again, I wish there wasn’t 6 of them!
 
I performed another lync and sync, carbs are no longer leaking. The top left carb will leak if engine is tilted but at level no carbs are leaking.

I replaced the plugs and engine started on muffs after a few cranks and died out shortly after, surging and sputtering. After a few more attempts I can get it to stay running for about a minute or so but it always eventually dies out. The engine is staying around 1000 rpm for idle on muffs, I do not know if the quick start feature is always engaged its running so rough here and surging up and down 100-200RPM its hard to tell whats what.

I noticed something new since on muffs I can hear a popping sound coming from exhaust. I hooked a timing light to cylinder #1 (top right cylinder when looking at engine spark plugs from stern of boat correct?) And the timing at about 1000 rpm (with or without quick start engaged hard to tell engine is running so rough) was -20 degrees, this seems way off doesn't it? Idle timing according to service manual is supposed to be 6 degrees +/- 1 ATDC #1 cylinder also once or twice in the few minutes I was testing it fired a spark near the #3 marking on the timing wheel as opposed to the -20 degrees, i'm not sure if my timing light screwed up or it really did throw an intermittent spark.

I bought a spark tester with adjustable gap to test spark should be here today and hoping to get into this a bit more.
 
Ok, I used a spark tester set at 7/16 in and tested all spark plugs. Cylinder #5 showed eratic spark, sometimes there sometimes not. I changed out the cables and the same cylinder still showed erratic spark firing and not firing, all other cylinder showed bright blue snap of a spark.

I pulled the fly week to inspect the stator, some black goo under the stator, it will need replacing in the future but I am not sure if that would be causing my hard starting rough running right now.

I tried to start it today mid day afternoon heat and she would not start. I took the small hoses off the primer solenoid to see if they were shooting fuel when I pressed the key and they were not, should i spit fuel when key is pressed but engine is not turning over? How much?

I noticed a crack in the fitting that fuel from the tank enters and houses the filter, fuel was spilling from this crack. I will replace this immediately to see if any changes, possibly sucking in air with the fuel?

I am possibly going to buy a new power pack and coil to see if that helps cylinder #5 as this one is likely nearly 30 years old anyway.

Should I be concerned with my PSI numbers Lbs/ft: 94 95 98 85 91 91?
 
If the stator is dripping a sticky looking "goo" on the powerhead, that would cause a voltage drop to the powerpack... yes, replace the stator if it's in the meltdown stage.

The fuel primer solenoid is NOT a pump... fuel flows theu it only when pressure is applied to it, either via the fuel primer bulb or the engine running.
 
Thank you Joe, I will replace the stator.

I made some progress today. I found a crack in the 90 degree fuel fitting that houses the fuel filter. I replaced that part and was able to start engine right up on muffs. I am assuming that was sucking in air with the gas and causing irregularities with fuel delivery. It was a small crack but definitely leaking fuel when enought pressure with priming bulb was applied otherwise I would not have found this.

Will run the boat on the water tomorrow to see how it goes!
 
In the water the boat has the same issue, it will come down on idle and stall out almost every time and is hard to start, but at least now it is starting

I took the carbs off and replaced the gasket at the intake manifold and re torqued everything with a torque wrench. I took the carbs apart and noticed all fuel bowls are warped which is why I see the minor leaking of gas. I read somewhere that the fuel bowls being warped will not cause any engine symptoms but leaking gas is an issue obviously so this has to be fixed. Is it true that warped carb bowls don't necessarily mean the engine will run rough because of it? I will try to fix these tomorrow.

If I advance the timing I can get the engine to idle for a bit longer but it idles at 1000 rpm while the lower unit is in a trash can full of water not under load, this is obviously higher than what it should be.

I have ordered a new power pack and spark plug wires, stator will be ordered next as I believe a poor working stator could fry a power pack. The culprit could be a bad powerpack as I thought I noticed my timing light going off at the wrong time.

Very frustrating but I feel I made a little progress.

I also hooked two clear 5/16in hoses up from the vapor seperator to the fuel rails supplying the carbs, I did notice two bubbles at the top of the clear plastic hoses but 100% clear good fuel mix going into the rails supplying the carbs, I'm assuming fuel supply is good at that point. I'm running out of ideas!

While taking off the carbs today I took off the intake manifolds to observe the reeds, I noticed one reed was not exactly seated as tight as the others leaving some light shining through at rest. I adjusted this reed, I did not notice a difference in performance, all other reeds are metal and look really good.
 
Here is a follow up. I know a lot of these threads dry up and you never figure out if the problem was solved by the owner!

The boat is starting fine now, mostly by advancing the idle ignition timing as much as it will go, this leads it to idle at about 900 RPM in gear and 1000 RPM in the water. Top end has not changed, boat runs great about 3000 RPM and above, from 2000-3000 RPM at times I could swear I hear an engine popping as if the timing is still off.

The boat still has a lean sneeze at idle and occasionally will stall out, not nearly as much as it was doing and 90% of the time it stays running. I am still trying to figure out this lean sneeze. As a follow up here is what I have done.

Rebuilt and cleaned carb's, adjusted float valves, sanded down float bowl bodies to get rid of warp, installed new intake gasket along with carbs.
Lync and sync after every carb adjustment.
New Spark plugs QL78YC
New water pump and lube
New Power pack, one new coil, and new inductive spark plug wires.
Replaced gasket to vacuum pump
Replaced red knob to solenoid
Replaced main fuel inlet fitting and filter
I took the flywheel cover off and need a new stator as I could see some goo, everything else in there looked ok.
This morning I tried some 16 oz seafoam to 1 gallon gas with 6 ounces 2 cycle oil and ran that until the gallon was about gone and now letting engine sit (lots of smoke)
I tested the fuel system, about 1-2 PSI vacuum before the pump and 6-7psi pressure after the pump, seems ok. VRO is still in the engine acting as a fuel pump but not an oil pump. I premix and the previous owner was responsible for disconnecting the system, I do not know if it was done correctly.

I can try the tooth picks in the idle air orifices trick but she still has a lean sneeze at idle. I have tried sticking my fingers in the throats of the carbs but it does not seem to solve anything

I have a propane torch, anywhere I should be directing the spray to try and eliminate a possible vacuum leak?

I made some progress, boat is in the water and can get from point A to B but I am afraid the lean sneeze could be an indicator of a massive failure down the road, still trying to figure that one out.
 
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