96 johnson 60hp, stall at 4200rpm, no alarm horn

[Beaux]

here is the situation:<br />was running my 15'boat (Tooth "ferry" ) for about 30 minutes at around 4200 rpm, no problem with motor in past or during that day. all of the sudden it feels as though my skeg hits the bottom as my motor immediately bogs and stalls. I was in 10' water and had plenty of fresh fuel/50:1 mix in tank. No warning horn sounded and no other sounds besides the motor stalling were heard. I tilted up/checked prop for tangle/etc. and found nothing. i tried cranking and motor spun fine but did not catch at all. I tried cranking a few times and then decided to anchor and let it sit. After about three-five minutes, i crank it up no problem and ran back home after slow idle in gear to make sure everything was running okay. The motor ran great and the water was peeing thru the telltale the entire time (although not a real strong stream).... does this sounds like an overheat issue? No alarms sounded (I have the older style controls that only use alarm not the lit panel and alarm) but i cant figure out what else it could be....any suggestions?? thanks

 

[ob]

Re: 96 johnson 60hp, stall at 4200rpm, no alarm horn

Beaux, There are several things that could cause this syptom.Fuel restriction(possibly pickup tube in tank ),Intermittent spark problem(possibly lanyard kill switch),overheat as you mentioned.When was the last time cooling system was serviced ie(waterpump replacement,thermostat)?You can carry a 163 degree temp stik along with you and check by touching to head and engine block after engine is up to temp.Should be temp alarm test slot on older style controls for testing overtemp alarm by inserting key.If not ,try grounding the tan wire over top of thermostat housing with key turned on.This test only insures that your buzzer is working ,not the temp sensor.

 

[Beaux]

Re: 96 johnson 60hp, stall at 4200rpm, no alarm horn

thanks OB...i will check those thigs and report back.

 

[Beaux]

Re: 96 johnson 60hp, stall at 4200rpm, no alarm horn

the cooling system has not been checked/changed since I have owned it....only 2-3 months... That will be my next project. The last service I have done to the motor was a lower unit lube change and I sync and linc'ed my carbs. The motor runs great though, before and after this stall incident, with WOT of 5800rpm and much better idling and transition to plane w/o stumble. The lower unit makes no noises and shift into gear is perfect and normal..... I always tend to look back on what I did last when something goes wrong...neither of these should cause this glitch should they?

 

[ob]

Re: 96 johnson 60hp, stall at 4200rpm, no alarm horn

Beaux, I would check out all of the easy things first .Remove each plug wire and if you have an ohm meter , check for good continuity form end to end while slightly bending back and forth.You mentioned having the older style controls. If you have the old style lanyard switch with rubber cover ,push button in and out and check for excessive travel.New style fork clip can also be borederline in holding switch points in open position.Next common problem is fuel restrictions in fixed jets on carbs to include pickup tubes in bowl.Gummy deposits are very common problem on outboards that have not been run regularly.<br />Did you happen to notice if your primer bulb was colapsed or firm when engine stalled at higher rpms?If it colapsed or was very soft it is indication of restriction or faulty primer bulb on suction side of pump.

 

[rudeafrican]

Re: 96 johnson 60hp, stall at 4200rpm, no alarm horn

Beaux,<br /><br />I know this sounds too obvious but have you checked your tank vent? An intermittant problem like this can be a real pain in the rear. It would be great if it never happened again but it if it does you'll have to trace it in logical steps such as checking temp at time of stall, checking primer bulb, opening fuel tank to check for vacuum, check for spark etc etc.<br /><br />Good luck