J
Jack Nienke
Guest
" Troubleshooting problems on
" Troubleshooting problems on 1992 Johnson 150 Silver Star with VRO still in use.
I think I have several issues, but don? have enough experience to know for certain if these are significant problems. Anyway, over the weekend I got out my Clymer manual and began with an annual physical for my motor. I first checked the compression using the following method:
1.Start engine on muffs to let engine warm to temp.
2.Removed all 6 spark plugs
3.Removed kill switch and engaged throttle to full (but out of gear)
4.Used screw-in type compression gauge in all six cylinders, cranking engine over with the starter for 5-10 seconds each
The compression is:
2=117psi 1= 120psi
4=115psi 3= 120psi
6=110psi 5=117psi
Please note that the cylinders were checked in 1,3,5,2,4,6 this may account for slightly lower compression in the 4 and 5 cylinders due to engine temp cooling some, but I am not sure. What do you guys think? I believed these numbers were okay so on to the physical.
Step 2
Used piston stop tool 384887 in 1 cylinder to align pointer Line A 1?ATDC ?Line B 1?BTDC - Line C exactly between marks A&B ?align pointer per manual
Step 3
I removed the throttle cable from the trunion pocket and disconnected from pin. Then synchronized the carburetor butterfly? to the closed position and tightened connector screws and link.
Step 4
Set Idle timing with OMC Analyzer 434017 6 degrees ATDC and Maximum advance at 20 degrees BTDC
Step 5
Set the pick up point so that the timing advance and carburetor butterfly? move ant the same time.
Finally, here are the problems:
The idle is around 1400 rpm per my OMC tach in the boat. I checked the Quick Start temp sensor (cold high resistance, warm low resistance) but the timing was not changed with the black and white power pack wire plugged in to temp sensor or grounded. I think the pack disables this above 900RPM?. I confirmed that the timing was not changing with a timing light. The timing light indicates the idle timing is 6 degrees ATDC with RPMS at 1400. I even moved the inner Timing Tab to retard the timing further (8 degrees ATDC), but RPMS remain too high. The fuel line nipple is clear and there doesn? seem to be any air bubbles in the fuel, and primer ball pumps up firm. I don? think there is a fuel restriction, What should my next steps be to get the Idle to reduce to 600-700 specification?
One last issue, I also checked the shift switch and all seems okay, but it does not seem to activate when shifting. If I manually activate the switch, it does cut 1,3, and 5 cylinders, just not when installed and shifting with the throttle control. It all seems free, lubricated, and has a fairly strong blue compression spring that appears to keep it pushed against the throttle pin. However, the throttle pin does not seem to move up enough to activate the shift switch. This seems like a strange design but I am not sure I understand if the switch is supposed to work every time it is shifted into or out of gear, or only when the shifter rod linkage kicks back from the gears meshing.
What to do about idle RPM? and shift switch operation?
Thanks in advance,
Jack Nienke "
" Troubleshooting problems on 1992 Johnson 150 Silver Star with VRO still in use.
I think I have several issues, but don? have enough experience to know for certain if these are significant problems. Anyway, over the weekend I got out my Clymer manual and began with an annual physical for my motor. I first checked the compression using the following method:
1.Start engine on muffs to let engine warm to temp.
2.Removed all 6 spark plugs
3.Removed kill switch and engaged throttle to full (but out of gear)
4.Used screw-in type compression gauge in all six cylinders, cranking engine over with the starter for 5-10 seconds each
The compression is:
2=117psi 1= 120psi
4=115psi 3= 120psi
6=110psi 5=117psi
Please note that the cylinders were checked in 1,3,5,2,4,6 this may account for slightly lower compression in the 4 and 5 cylinders due to engine temp cooling some, but I am not sure. What do you guys think? I believed these numbers were okay so on to the physical.
Step 2
Used piston stop tool 384887 in 1 cylinder to align pointer Line A 1?ATDC ?Line B 1?BTDC - Line C exactly between marks A&B ?align pointer per manual
Step 3
I removed the throttle cable from the trunion pocket and disconnected from pin. Then synchronized the carburetor butterfly? to the closed position and tightened connector screws and link.
Step 4
Set Idle timing with OMC Analyzer 434017 6 degrees ATDC and Maximum advance at 20 degrees BTDC
Step 5
Set the pick up point so that the timing advance and carburetor butterfly? move ant the same time.
Finally, here are the problems:
The idle is around 1400 rpm per my OMC tach in the boat. I checked the Quick Start temp sensor (cold high resistance, warm low resistance) but the timing was not changed with the black and white power pack wire plugged in to temp sensor or grounded. I think the pack disables this above 900RPM?. I confirmed that the timing was not changing with a timing light. The timing light indicates the idle timing is 6 degrees ATDC with RPMS at 1400. I even moved the inner Timing Tab to retard the timing further (8 degrees ATDC), but RPMS remain too high. The fuel line nipple is clear and there doesn? seem to be any air bubbles in the fuel, and primer ball pumps up firm. I don? think there is a fuel restriction, What should my next steps be to get the Idle to reduce to 600-700 specification?
One last issue, I also checked the shift switch and all seems okay, but it does not seem to activate when shifting. If I manually activate the switch, it does cut 1,3, and 5 cylinders, just not when installed and shifting with the throttle control. It all seems free, lubricated, and has a fairly strong blue compression spring that appears to keep it pushed against the throttle pin. However, the throttle pin does not seem to move up enough to activate the shift switch. This seems like a strange design but I am not sure I understand if the switch is supposed to work every time it is shifted into or out of gear, or only when the shifter rod linkage kicks back from the gears meshing.
What to do about idle RPM? and shift switch operation?
Thanks in advance,
Jack Nienke "
