1990 E70TLESB Motor
Problems I was trying to fix:
1. Motor would not idle in gear, forward or reverse. You had to put it in gear and goose the throttle as quick as you could to try to keep it running. Last time I was out with it had a slight miss around 3000rpm that cleared up at full throttle.
2. VRO pump was leaking both fuel and oil.
What I did to try to resolve problems
1. Rebuild kit in all 3 carbs.
2. Replaced VRO with a 3 hose 438559 OMC fuel pump
3. I have OMC Service Manual so after doing the above 2 things I went on to synchronization and Linkage adjustment procedure. Method B in the manual.
4. Idle speed adjustment. This is where things started going south for me. (note: I was cheating, was not in the water unrestrained, it was in a 100qt cooler with the hose constantly feeding it) When I adjust the idle speed down to 800 motor just dies in gear, it will idle there but don't try to spin that prop. Upped the idle to about 1100 and moved on to next step to see if I had problems elsewhere that were showing up here.
5. Cam follower pickup. No problem doing this adjustment.
6. Throttle Cam adjustment. No problem here
7. Wide open throttle stop. No problem here
8. Maximum Spark advance. This is where I started getting confused what was going on and jumped all around trying to figure out what exactly is going on, I hooked up timing light, Cylinder 1 (1 is the top cylinder correct?) and looked at where it was timed at idle. It was showing 4-5 degrees after TDC. Long story short I tried adjusting the idle screw to bring it closer to TDC, which it does but then the idle goes way to high.
Found in service manual under adjustments for 65RS motor that at idle timing should be about 1 degree before TDC so I am assuming 70 should also be somewhere close to that. If i slide the timing advance all the way to where it would be at full throttle it shows 14 to 15 Degrees before TDC.
I at first thought my flywheel might be tweaked but at the start of the procedure you set the pointer on TDC by checking it against the piston which I did, was only off a slight bit.
Seems that if i could get my timing to before TDC motor would run much better but when I adjust towards that idle goes way to high. Carbs on this model have no low speed adjustment screws so no adjustments to be done on carbs.
What am i missing or where do I go from here. Motor sounds much better than before the work, I am just totally confused on this timing issue. Will have it on the lake tomorrow and see how it actually runs moving the boat around and will update this when I get home.
Thanks in advance for any wisdom you all can share with me.
Thanks,
Chris
Problems I was trying to fix:
1. Motor would not idle in gear, forward or reverse. You had to put it in gear and goose the throttle as quick as you could to try to keep it running. Last time I was out with it had a slight miss around 3000rpm that cleared up at full throttle.
2. VRO pump was leaking both fuel and oil.
What I did to try to resolve problems
1. Rebuild kit in all 3 carbs.
2. Replaced VRO with a 3 hose 438559 OMC fuel pump
3. I have OMC Service Manual so after doing the above 2 things I went on to synchronization and Linkage adjustment procedure. Method B in the manual.
4. Idle speed adjustment. This is where things started going south for me. (note: I was cheating, was not in the water unrestrained, it was in a 100qt cooler with the hose constantly feeding it) When I adjust the idle speed down to 800 motor just dies in gear, it will idle there but don't try to spin that prop. Upped the idle to about 1100 and moved on to next step to see if I had problems elsewhere that were showing up here.
5. Cam follower pickup. No problem doing this adjustment.
6. Throttle Cam adjustment. No problem here
7. Wide open throttle stop. No problem here
8. Maximum Spark advance. This is where I started getting confused what was going on and jumped all around trying to figure out what exactly is going on, I hooked up timing light, Cylinder 1 (1 is the top cylinder correct?) and looked at where it was timed at idle. It was showing 4-5 degrees after TDC. Long story short I tried adjusting the idle screw to bring it closer to TDC, which it does but then the idle goes way to high.
Found in service manual under adjustments for 65RS motor that at idle timing should be about 1 degree before TDC so I am assuming 70 should also be somewhere close to that. If i slide the timing advance all the way to where it would be at full throttle it shows 14 to 15 Degrees before TDC.
I at first thought my flywheel might be tweaked but at the start of the procedure you set the pointer on TDC by checking it against the piston which I did, was only off a slight bit.
Seems that if i could get my timing to before TDC motor would run much better but when I adjust towards that idle goes way to high. Carbs on this model have no low speed adjustment screws so no adjustments to be done on carbs.
What am i missing or where do I go from here. Motor sounds much better than before the work, I am just totally confused on this timing issue. Will have it on the lake tomorrow and see how it actually runs moving the boat around and will update this when I get home.
Thanks in advance for any wisdom you all can share with me.
Thanks,
Chris
