89 Gt150 running problem's

[moose8]

Could use some help. I have a Johnson GT150 (TJ150SLCEM)that had a low fuel alarm.Replaced anti-siphion valve on main tank.Did not find one on auxl.tank.That seem to stop alarm. Also replaced fuel filter and bulb. Also replace t-stat's.has new plugs. Did a compresson test all cyclinders around 95 on a cold engine. Had to replace recterfer a couple of years ago. Took boat to lake today very hard to start and does not wont to idle unless reved up.Also when in gear will not accel above 1500 rps (1/4 throttle)with out dying.Tried pumping bulb, no change.pressing in key for choke does not change. At WOT in gear will stall and is hard to get into gear with out dying. Last time boat was out (2 weeks ago)was slugish about getting on plane (like boat was full). Boat has not been used very much in last couple of years. I am an auto tech. but this thing starting to get me. Any help would be great. Thanks

 

[HighTrim]

Re: 89 Gt150 running problem's

Is she sparking on all cylinders?

 

[emdsapmgr]

Re: 89 Gt150 running problem's

Follow High Trim's advice and check your spark when idling in gear at the dock. An inductive timing light should help you determine if you have good spark on all 6 plugs. You can also use an insulated pair of plug pliers and pull each spark plug boot off each plug one-at-a-time. See what happens to the rpm's on each plug when the wire is unplugged.

 

[moose8]

Re: 89 Gt150 running problem's

Ok I will check for spark. It is very hard to start. Maybe low spark is the problem. Will bring tools home this weekend. Will let you know what I find. Thanks, if you think of anything else to try or inspect.

 

[moose8]

Re: 89 Gt150 running problem's

Ok checked spark today. No spark on any cylinder. Checked coils by ohm ing they all seem ok according to service manual. Power pack test not so good. I guess I will try to find a pack Monday. Everyone around here already closed. If anyone thinks of anything also let me know. Thanks

 

[emdsapmgr]

Re: 89 Gt150 running problem's

You are going the right direction. Unlikely all 6 coils failed at the same time. In addition to the power pack, you also have a timer base and stator. All are expensive to replace. Additional diagnosis from the factory manual should help you make the right component replacment decision.

 

[jonesg]

Re: 89 Gt150 running problem's

You are going the right direction. Unlikely all 6 coils failed at the same time. .

My mechanic said the same thing,
he was right, new pack and it fired right up.

 

[moose8]

Re: 89 Gt150 running problem's

Ok went to lake last Friday,boat still hard to start but did idle better and went into gear at first and did not stall.Took off and before planing fell flat on its face.Did idle back to boat dock.Had my timing light to check for firing at all cylinders.Showed spark at all wires,but right bank did not flash as even as left bank.pulled spark plug wires on right bank.No spark at any plug.Pull left side,would spark an inch from the plugs and just about stall engine. I will go back and re ohm as much stuff as possible. All coils ohmed ok last time.May swap coils from side to side. Had heard of possible stator could cause this.Any idea's,I am running out.

 

[emdsapmgr]

Re: 89 Gt150 running problem's

With a new pack, there are two more critical componets to check, the timer/sensor base and the stator. Either could contribute to the problem. Both are expensive. The factory manual has specific condemning voltage output targets which are measured with a peak-reading voltmeter. Worth your while to spend some time testing the output on both.

 

[moose8]

Re: 89 Gt150 running problem's

Ok took boat out after replacing stator and butting carb.'s in time.Boat runs like a champ. Starts right up idles good and gets on plane very quick.Thanks for every ones help

 

[HighTrim]

Re: 89 Gt150 running problem's

Ty for the update.