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Author Topic:   1988 Johnson 70hp Engine alarm

Sfef84 posted 08-15-2011 03:19 PM ET (US)
I have twin 1988 Johnson 70hp motors on my Raider. I have run the motors on the hose for 10-30 minutes at a time with no sputtering, coughing, popping, wheezing etc. This Saturday, the Raider finally went in the water. Seeing as I have never had them run on anything but the hose, I let them idle for 15 minutes with no [sputtering, coughing, popping, wheezing etc.].
Ran them at 5-MPH for about ten minutes. Ran them on a plane for about three minutes, and I heard the alarm going off for the port motor. The motor was turned off and allowed to cool down--assuming that is what the alarm went off for--until the alarm did not sound when key was turned. Turned on--then died. Trimmed it up and put boat back on trailer.
Next morning, with the port motor on the hose, I turn the key for a split second and the motor turns on and runs like a champ. Let it sit for 20 minutes running and no [sputtering, coughing, popping, wheezing etc.].
I do the same procedure as on Saturday--let idle at dock, put put around, get on plane--and the alarm goes off again.
Both prime bulbs do not stay hard but does not seem to effect the starboard motor.Both motors run from same fuel source--one 1 tank, dual pickups water separators. I will do the aux fuel source test today with a 5-gallon tank with fresh gas-oil mix and working primer bulb, and see what happens.
Any other checks I should make?
Port motor had [sputtering, coughing, popping, wheezing etc.] idling until the carburetor was re-built, and [sputtering, coughing, popping, wheezing etc.] went away. Motor has been on a total of an hour on the hose and 20 minutes in the salt water since. Cooling system indicator stream is just as strong on the hose as in the water. Do not have temperature gauge on the engine. Port engine will run all day in idle, forward and reverse on hose but once the alarm sounds, I can only keep it running at 2,000-RPM, but [the engine] will die when put in gear
A2J15Sport posted 08-15-2011 06:23 PM ET (US)
The telltale stream is no indication of actual cooling.
Only an infared temp sensor can give you a true sense of what is happening.
If the alarm was steady, it's overheat.
Sfef84 posted 08-15-2011 10:52 PM ET (US)
Talked to my mechanic buddy and said that a stuck thermostat is probably the [cause of the alarm]. He mentioned that the combination of high ambient temp under the cowling and 95-degree-F water, the gasoline in the carbs could be vaporizing the fuel, causing the motor to run lean. That would explain [all] of my problem.
Time to pull the thermostat and hopefully the [overheat alarm] will be resolved.
jimh posted 08-15-2011 11:02 PM ET (US)
To interpret the meaning of the aural alarm on older OMC outboard engines, see
Warning Horn Signals
http://continuouswave.com/whaler/reference/warningHornSignals.html
Sfef84 posted 08-16-2011 09:02 AM ET (US)
Referring to Note #1:
If you engine overheats you should leave it in idle and not turn it off immediately?
Wouldn't that do more harm than good?
jimh posted 08-16-2011 08:01 PM ET (US)
Please explain how you came to have that idea.
Tohsgib posted 08-16-2011 10:13 PM ET (US)
"If you engine overheats you should leave it in idle and not turn it off immediately?"
Yes/wrong! turn it off immediately.
dgoodhue posted 08-16-2011 11:27 PM ET (US)
My 60hp Evinrude was constantly giving me over heat alarms after about 5 minutes of driving. My engine clearly wasn't over heating, the head was barely warm when took the cover off. My false alarm was because my powerpacks ground wasn't hooked up. ( put your hand in the water before touching the head in case it's truly over heating.). OMC also had a service bulletin for the 60/70 on over heating.
seahorse posted 08-16-2011 11:45 PM ET (US)
Those 3 cylinder 60's and 70's had service bulletins back in the early '90s to help overheating problems. Be sure to use the complete factory water pump kit as it is a high-flow design and comes with the fittings to reposition the water tell-tale from the side of the exhaust cover to the top of the exhaust area. That removes trapped air better and increases water pressure. A new thermostat relief spring is also included because of the higher water pressure.
There are also service bulletins about improved temp senders and on jetting and timing changes for '91 thru '93 motors.
See an established dealer to find out if any or all the improvements apply to your motors.
Sfef84 posted 08-17-2011 08:58 AM ET (US)
"Please explain how you came to have that idea"
Think of what the responses would have been to my original post if I said the following:
"engine alarm went off due to overheating. Engine stopped running after backing it down to idle. The powerhead was hot to the touch. Any ideas on why it will not turn over"
The responses would have been:
"You are incompetent"
"Why would you leave it running if you knew it was overheating"
"Why do you think the alarm is so loud and annoying? So you will turn your motor off"
etc
etc
I can MAYBE see the logic IF and only IF
- you see a strong tell tail that is warm
- you are offshore and are willing to take a calculated risk
- you have a motor that will go into SLOW mode or a 4 stroke that will shut itself down to maintain a proper operating temp
- Temperature gauge holds steady(Even in this case, I would shut it down)
dgoodhue and seahorse. Appreciate the info. Ill check it out.
Sourpuss1 posted 08-17-2011 12:51 PM ET (US)
Sfef84,
I don't see that instruction in note #1, but I think I know what you are getting at.
If you starve an outboard of water and get a temperature alarm, what do you do? Stop the boat, put it in reverse and try to clear weeds/mud/plastic bag from the pick-up right? then proceed carefully forward and monitor temperature and tell-tale. This is a 30 second fix after the alarm. If the alarm continues and the motor does not return to normal temp (another 30-60 seconds), then you have a real problem. Shut the motor down and wait....
Tohsgib posted 08-17-2011 03:24 PM ET (US)
Granted I do the same but tell-tail usually starts pumping immediately, just like when you start it in the morning. If not then shut it down. An engine will cool much quicker with water running through it. However...on an OMC that went into SAFE mode you must restart the engine to reset it, at least with my 225.
tedious posted 08-22-2011 09:23 AM ET (US)
Here's a collection of notes from when I owned a 1989 70 - various TSBs, part numbers, and stuff I collected. I am sure the formatting is going to be a bit off, but maybe some of it will be helpful.
OMC 70 TSBs
SB2221 dated Feb1990 changed temp sensor, PN 584166 new switch has 7 1/4 inch tan wire with blue stripe.
SB2225 dated April 1990 change thermostat seat from 2 piece to 1 piece, old has stainless cup for rubber seal, you remove old seal and cup, replace with 1 piece seal PN 336416.Also applies to V4/6/8.
SB2276R1 dated April 1994 relocated tattle tail nipple from side of block to top of engine to vent air for better cooling at idle. Waterpump kit 432955 has SB 2276R1 in kit, a choice of 2 new pressure relief springs depending on model of engine with cover, and improved impeller.

60 & 70 hp service bulletins for cooling and overheating
SB 2221 Temp sensor new sensor pn 584166, tan/blue stripe wire.
SB 2225 thermostat seat new seat pn 336416
SB 2271 jet and timing kits
SB 2276R1 relocate tattle tale nipple to top of block.
SB 2276R1 and new pressure relief springs comes in waterpump kit pn 432955.

The late production carbs have adjustable slow speed jets. There were a couple of bulletins out dealing with issues about water pump changes, overboard water outlet relocation, high speed jet changes, temp sender changes etc.
One of the things we noticed early on was that the motors that had issues with #2 cylinder all had some similiar things going on. Most motors were set up at less than 5800 rpm, some had incorrect spark plugs and some were run almost all the time in the mid range (cruise) mode. Motors that were run at wide open didn't seem to have issues.
On motors we were involved with we made all the recommended changes but some still had some repete issues. We then started to make changes to the mid range jets. (That's basically what you're running on in cruise mode) In the cruise range you're running on full spark advance and very little fuel. On those motors #2 runs the hottest. On prolonged mid rane running the heat in #2 built up enough to cause problems. If you made the same trip at wot there was enough fuel going in to control the combustion temp.
On motors that we richened up in the mid range by 2 or 3 numbers didn't seem the have repeat issues.

Here are the important bulletins concerning the 60-70hp 3 bangers.
60 & 70 hp service bulletins for cooling and overheating
SB 2221 Temp sensor new sensor pn 584166, tan/blue stripe wire.
SB 2225 thermostat seat new seat pn 336416, may not need this in fresh water.
SB 2271 jet and timing kits ds
SB 2276R1 relocate tattle tale nipple to top of block.
SB 2276R1 and new pressure relief springs comes in waterpump kit pn 432955.

Parts Order
584166 updated temp sensor (not sure I want this – new one is hotter?) $39.34
336416 new thermostat seat $3.08
432955 waterpump kit includes telltale relocate kit $74.68
318581 shift rod seal $4.08
394409 Thermostat assembly (also 434137, 18-3500) $15.00 or so
776964 Adhesive M = 3M 847 $17.35
329830 Thermostat cover gasket $1.40
330273 Thermostat valve seat cup $4.48
320880 Thermostat seal $2.00
326567 OMC Seal Installer (probably not)
18-9070 Gasket Sealant $7.49
432230 Lanyard $11.95
0583891 Warning Horn $73.88
0582399 Rectifier and Lead $48.99
051733 Ring Terminal (3 required) $0.73
398729 Carb Repair Kit $29.23
***************************************************** 10/22/09
329833 Exhaust cover gasket
314021 Exhaust manifold bumper
321886 Telltale Elbow
Sfef84 posted 08-23-2011 01:04 AM ET (US)
Tedious-
Excellent list. I will refrain from saying it must have been ________ to put together.
To follow up on my issue, I pulled the thermostat but did not do the hot water test.
Credit must go to my mechanic. He stated that my overheat issue was most likely was a stuck thermostat. He continued to say that the motor would not start because of vaporized fuel. This was caused by ambient temp in cowling, 95F water and 110F weather. To take it a step further, the fuel pump was working fine but the motor was running extra lean.
To confirm that the motor was running lean, I pulled the spark plugs and what do ya know? Full of oil.
After cleaning the plugs, my buddy and I got the motor started and let it run in high idle (2500-3500[only because that was the only RPM it would stay running]) to burn off the oil in the cylinders. She smoked like a chimney!
All is in good working order (knock on wood)
mb159 posted 08-23-2011 03:40 PM ET (US)
Just went through this myself with a 1996 Johnson 88SPL. Replaced thermostats,( $200.00 ), still had alarm at WOT Replaced water pump, ( $150.00 ), still had alarm at WOT...
Removed engine cover, checked head temperature with infrared temperature sensor, had NO overheat problem. Replaced BOTH temperature sensors, ( $ 34.00 ea. ). NO MORE alarm at WOT.
The key is to immediately check the temperature of the heads when the alarm sounds. This will let you know pretty quickly whether you have a REAL overheat problem or a sensor or horn problem.
At least I have peace of mind that my thermostats and water pump are PRIMO!!
EHA posted 10-16-2011 09:19 PM ET (US)
Please contact me at eander31@gmail.com if you would be willing to sell your raider or if you are able to help me locate one.
Thanks
Erik

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Author	Topic: 1988 Johnson 70hp Engine alarm
Sfef84	posted 08-15-2011 03:19 PM ET (US) I have twin 1988 Johnson 70hp motors on my Raider. I have run the motors on the hose for 10-30 minutes at a time with no sputtering, coughing, popping, wheezing etc. This Saturday, the Raider finally went in the water. Seeing as I have never had them run on anything but the hose, I let them idle for 15 minutes with no [sputtering, coughing, popping, wheezing etc.]. Ran them at 5-MPH for about ten minutes. Ran them on a plane for about three minutes, and I heard the alarm going off for the port motor. The motor was turned off and allowed to cool down--assuming that is what the alarm went off for--until the alarm did not sound when key was turned. Turned on--then died. Trimmed it up and put boat back on trailer. Next morning, with the port motor on the hose, I turn the key for a split second and the motor turns on and runs like a champ. Let it sit for 20 minutes running and no [sputtering, coughing, popping, wheezing etc.]. I do the same procedure as on Saturday--let idle at dock, put put around, get on plane--and the alarm goes off again. Both prime bulbs do not stay hard but does not seem to effect the starboard motor.Both motors run from same fuel source--one 1 tank, dual pickups water separators. I will do the aux fuel source test today with a 5-gallon tank with fresh gas-oil mix and working primer bulb, and see what happens. Any other checks I should make? Port motor had [sputtering, coughing, popping, wheezing etc.] idling until the carburetor was re-built, and [sputtering, coughing, popping, wheezing etc.] went away. Motor has been on a total of an hour on the hose and 20 minutes in the salt water since. Cooling system indicator stream is just as strong on the hose as in the water. Do not have temperature gauge on the engine. Port engine will run all day in idle, forward and reverse on hose but once the alarm sounds, I can only keep it running at 2,000-RPM, but [the engine] will die when put in gear
A2J15Sport	posted 08-15-2011 06:23 PM ET (US) The telltale stream is no indication of actual cooling. Only an infared temp sensor can give you a true sense of what is happening. If the alarm was steady, it's overheat.
Sfef84	posted 08-15-2011 10:52 PM ET (US) Talked to my mechanic buddy and said that a stuck thermostat is probably the [cause of the alarm]. He mentioned that the combination of high ambient temp under the cowling and 95-degree-F water, the gasoline in the carbs could be vaporizing the fuel, causing the motor to run lean. That would explain [all] of my problem. Time to pull the thermostat and hopefully the [overheat alarm] will be resolved.
jimh	posted 08-15-2011 11:02 PM ET (US) To interpret the meaning of the aural alarm on older OMC outboard engines, see Warning Horn Signals http://continuouswave.com/whaler/reference/warningHornSignals.html
Sfef84	posted 08-16-2011 09:02 AM ET (US) Referring to Note #1: If you engine overheats you should leave it in idle and not turn it off immediately? Wouldn't that do more harm than good?
jimh	posted 08-16-2011 08:01 PM ET (US) Please explain how you came to have that idea.
Tohsgib	posted 08-16-2011 10:13 PM ET (US) "If you engine overheats you should leave it in idle and not turn it off immediately?" Yes/wrong! turn it off immediately.
dgoodhue	posted 08-16-2011 11:27 PM ET (US) My 60hp Evinrude was constantly giving me over heat alarms after about 5 minutes of driving. My engine clearly wasn't over heating, the head was barely warm when took the cover off. My false alarm was because my powerpacks ground wasn't hooked up. ( put your hand in the water before touching the head in case it's truly over heating.). OMC also had a service bulletin for the 60/70 on over heating.
seahorse	posted 08-16-2011 11:45 PM ET (US) Those 3 cylinder 60's and 70's had service bulletins back in the early '90s to help overheating problems. Be sure to use the complete factory water pump kit as it is a high-flow design and comes with the fittings to reposition the water tell-tale from the side of the exhaust cover to the top of the exhaust area. That removes trapped air better and increases water pressure. A new thermostat relief spring is also included because of the higher water pressure. There are also service bulletins about improved temp senders and on jetting and timing changes for '91 thru '93 motors. See an established dealer to find out if any or all the improvements apply to your motors.
Sfef84	posted 08-17-2011 08:58 AM ET (US) "Please explain how you came to have that idea" Think of what the responses would have been to my original post if I said the following: "engine alarm went off due to overheating. Engine stopped running after backing it down to idle. The powerhead was hot to the touch. Any ideas on why it will not turn over" The responses would have been: "You are incompetent" "Why would you leave it running if you knew it was overheating" "Why do you think the alarm is so loud and annoying? So you will turn your motor off" etc etc I can MAYBE see the logic IF and only IF - you see a strong tell tail that is warm - you are offshore and are willing to take a calculated risk - you have a motor that will go into SLOW mode or a 4 stroke that will shut itself down to maintain a proper operating temp - Temperature gauge holds steady(Even in this case, I would shut it down) dgoodhue and seahorse. Appreciate the info. Ill check it out.
Sourpuss1	posted 08-17-2011 12:51 PM ET (US) Sfef84, I don't see that instruction in note #1, but I think I know what you are getting at. If you starve an outboard of water and get a temperature alarm, what do you do? Stop the boat, put it in reverse and try to clear weeds/mud/plastic bag from the pick-up right? then proceed carefully forward and monitor temperature and tell-tale. This is a 30 second fix after the alarm. If the alarm continues and the motor does not return to normal temp (another 30-60 seconds), then you have a real problem. Shut the motor down and wait....
Tohsgib	posted 08-17-2011 03:24 PM ET (US) Granted I do the same but tell-tail usually starts pumping immediately, just like when you start it in the morning. If not then shut it down. An engine will cool much quicker with water running through it. However...on an OMC that went into SAFE mode you must restart the engine to reset it, at least with my 225.
tedious	posted 08-22-2011 09:23 AM ET (US) Here's a collection of notes from when I owned a 1989 70 - various TSBs, part numbers, and stuff I collected. I am sure the formatting is going to be a bit off, but maybe some of it will be helpful. OMC 70 TSBs SB2221 dated Feb1990 changed temp sensor, PN 584166 new switch has 7 1/4 inch tan wire with blue stripe. SB2225 dated April 1990 change thermostat seat from 2 piece to 1 piece, old has stainless cup for rubber seal, you remove old seal and cup, replace with 1 piece seal PN 336416.Also applies to V4/6/8. SB2276R1 dated April 1994 relocated tattle tail nipple from side of block to top of engine to vent air for better cooling at idle. Waterpump kit 432955 has SB 2276R1 in kit, a choice of 2 new pressure relief springs depending on model of engine with cover, and improved impeller. 60 & 70 hp service bulletins for cooling and overheating SB 2221 Temp sensor new sensor pn 584166, tan/blue stripe wire. SB 2225 thermostat seat new seat pn 336416 SB 2271 jet and timing kits SB 2276R1 relocate tattle tale nipple to top of block. SB 2276R1 and new pressure relief springs comes in waterpump kit pn 432955. The late production carbs have adjustable slow speed jets. There were a couple of bulletins out dealing with issues about water pump changes, overboard water outlet relocation, high speed jet changes, temp sender changes etc. One of the things we noticed early on was that the motors that had issues with #2 cylinder all had some similiar things going on. Most motors were set up at less than 5800 rpm, some had incorrect spark plugs and some were run almost all the time in the mid range (cruise) mode. Motors that were run at wide open didn't seem to have issues. On motors we were involved with we made all the recommended changes but some still had some repete issues. We then started to make changes to the mid range jets. (That's basically what you're running on in cruise mode) In the cruise range you're running on full spark advance and very little fuel. On those motors #2 runs the hottest. On prolonged mid rane running the heat in #2 built up enough to cause problems. If you made the same trip at wot there was enough fuel going in to control the combustion temp. On motors that we richened up in the mid range by 2 or 3 numbers didn't seem the have repeat issues. Here are the important bulletins concerning the 60-70hp 3 bangers. 60 & 70 hp service bulletins for cooling and overheating SB 2221 Temp sensor new sensor pn 584166, tan/blue stripe wire. SB 2225 thermostat seat new seat pn 336416, may not need this in fresh water. SB 2271 jet and timing kits ds SB 2276R1 relocate tattle tale nipple to top of block. SB 2276R1 and new pressure relief springs comes in waterpump kit pn 432955. Parts Order 584166 updated temp sensor (not sure I want this – new one is hotter?) $39.34 336416 new thermostat seat $3.08 432955 waterpump kit includes telltale relocate kit $74.68 318581 shift rod seal $4.08 394409 Thermostat assembly (also 434137, 18-3500) $15.00 or so 776964 Adhesive M = 3M 847 $17.35 329830 Thermostat cover gasket $1.40 330273 Thermostat valve seat cup $4.48 320880 Thermostat seal $2.00 326567 OMC Seal Installer (probably not) 18-9070 Gasket Sealant $7.49 432230 Lanyard $11.95 0583891 Warning Horn $73.88 0582399 Rectifier and Lead $48.99 051733 Ring Terminal (3 required) $0.73 398729 Carb Repair Kit $29.23 ***************************************************** 10/22/09 329833 Exhaust cover gasket 314021 Exhaust manifold bumper 321886 Telltale Elbow
Sfef84	posted 08-23-2011 01:04 AM ET (US) Tedious- Excellent list. I will refrain from saying it must have been ________ to put together. To follow up on my issue, I pulled the thermostat but did not do the hot water test. Credit must go to my mechanic. He stated that my overheat issue was most likely was a stuck thermostat. He continued to say that the motor would not start because of vaporized fuel. This was caused by ambient temp in cowling, 95F water and 110F weather. To take it a step further, the fuel pump was working fine but the motor was running extra lean. To confirm that the motor was running lean, I pulled the spark plugs and what do ya know? Full of oil. After cleaning the plugs, my buddy and I got the motor started and let it run in high idle (2500-3500[only because that was the only RPM it would stay running]) to burn off the oil in the cylinders. She smoked like a chimney! All is in good working order (knock on wood)
mb159	posted 08-23-2011 03:40 PM ET (US) Just went through this myself with a 1996 Johnson 88SPL. Replaced thermostats,( $200.00 ), still had alarm at WOT Replaced water pump, ( $150.00 ), still had alarm at WOT... Removed engine cover, checked head temperature with infrared temperature sensor, had NO overheat problem. Replaced BOTH temperature sensors, ( $ 34.00 ea. ). NO MORE alarm at WOT. The key is to immediately check the temperature of the heads when the alarm sounds. This will let you know pretty quickly whether you have a REAL overheat problem or a sensor or horn problem. At least I have peace of mind that my thermostats and water pump are PRIMO!!
EHA	posted 10-16-2011 09:19 PM ET (US) Please contact me at eander31@gmail.com if you would be willing to sell your raider or if you are able to help me locate one. Thanks Erik