The engine starts fine, idles fine, has good RPM's in neutral, but has a top RPM in forward of 1200. So what's changed?
2004 Season
3 bladed Indigo 10x7.4 prop.
2400 Max RPM's
Before 2005 Launch
1) Replaced propeller with 2 bladed 12x8 folding.
2) Installed a dripless shaft seal.
Launch 2005
2100 Max RPM's. Assume drop in RPM's is due to different propeller.
Spring 2005
1) Installed Ignitor electronic ignition (Moyer).
2) New distributor cap (Moyer).
3) New spark plug wires (Moyer).
4) New spark plugs.
5) Installed new water temp sending unit (gauge was fine, sending unit was bad).
Same 2100 Max RPM's after installation.
Summer 2005
Max RPM's seems to gradually decreased to 1200. One day out it was 1900, next time it was 1700, then 1200.
Round 1:
Noticed a small amount of oil on top of coil. Replaced coil with Moyer coil part IGLM_05_31.
Still 1200 RPM's max.
Round 2:
Decided problem may be fuel related, so:
1) New fuel line from the gas tank (Moyer).
2) Installed manual in-line primer bulb on the gas line just before the Racor filter per Moyer web site suggestion.
3) Added a Racor fuel filter (Moyer).
4) Added a engine mounted electric pump (bought Moyer kit FPMP_10_52).
5) In-line gas filter (came in Moyer kit).
6) Oil safety switch. (came in Moyer kit). Engine didn't have one before.
7) Also replaced the oil pressure adjustment with an early model style (Moyer) as oil pressure has always been erratic. Press is steady now at 40 pounds. (The one thing I was able to correct!)
After all of above, still max RPM's of 1200. One change... engine now stalls under load after a few minutes. Just stops running like the key was turned off. Will restart either immediately or after a minute or two. I've run it at about 1200 RPM's in neutral for more than an hour with no stalling. When running wide open at 1200 RPMs, it sounds like its laboring.
Round 3:
Then I checked compression.
#1 = 130
#2 = 90
#3 = 130
#4 = 130
I put some MMO into #2 and it retested at 130.
Round 4:
Then I checked timing. Under load pulling at the dock lines, I made a very slight adjustment to the timing which improved the RPM by a very small amount. Now at about 1220.
The engine does have a small amount of blow by at times with exhaust coming out of the oil filler cap. It has had this for a few seasons.
I added 10 oz of MMO per 10 gals of gas and ran the engine in neutral at 1200 RPM's for an hour.
Rechecked TDC of #1 piston and rotor was positioned at #1 plug wire. Then check that order, going clockwise, is 1,2,4,3.
Tonight I got the boat out from the dock far enough to be in clear water and checked the prop and shaft underwater. There is nothing wrapped around it. The shaft turns freely in neutral. It does take quite a bit of force to shift into forward, but then the shifter has always been fairly stiff. With the shifter in forward, I can easily hand crank the engine and shaft.
The engine stalled 3 times in the ten minutes of running under load (may be the oil safety switch?). It runs fine at about 1/3 to 1/2 throttle, past that and it sounds like it's laboring and bogging down.
I'm out of ideas.
2004 Season
3 bladed Indigo 10x7.4 prop.
2400 Max RPM's
Before 2005 Launch
1) Replaced propeller with 2 bladed 12x8 folding.
2) Installed a dripless shaft seal.
Launch 2005
2100 Max RPM's. Assume drop in RPM's is due to different propeller.
Spring 2005
1) Installed Ignitor electronic ignition (Moyer).
2) New distributor cap (Moyer).
3) New spark plug wires (Moyer).
4) New spark plugs.
5) Installed new water temp sending unit (gauge was fine, sending unit was bad).
Same 2100 Max RPM's after installation.
Summer 2005
Max RPM's seems to gradually decreased to 1200. One day out it was 1900, next time it was 1700, then 1200.
Round 1:
Noticed a small amount of oil on top of coil. Replaced coil with Moyer coil part IGLM_05_31.
Still 1200 RPM's max.
Round 2:
Decided problem may be fuel related, so:
1) New fuel line from the gas tank (Moyer).
2) Installed manual in-line primer bulb on the gas line just before the Racor filter per Moyer web site suggestion.
3) Added a Racor fuel filter (Moyer).
4) Added a engine mounted electric pump (bought Moyer kit FPMP_10_52).
5) In-line gas filter (came in Moyer kit).
6) Oil safety switch. (came in Moyer kit). Engine didn't have one before.
7) Also replaced the oil pressure adjustment with an early model style (Moyer) as oil pressure has always been erratic. Press is steady now at 40 pounds. (The one thing I was able to correct!)
After all of above, still max RPM's of 1200. One change... engine now stalls under load after a few minutes. Just stops running like the key was turned off. Will restart either immediately or after a minute or two. I've run it at about 1200 RPM's in neutral for more than an hour with no stalling. When running wide open at 1200 RPMs, it sounds like its laboring.
Round 3:
Then I checked compression.
#1 = 130
#2 = 90
#3 = 130
#4 = 130
I put some MMO into #2 and it retested at 130.
Round 4:
Then I checked timing. Under load pulling at the dock lines, I made a very slight adjustment to the timing which improved the RPM by a very small amount. Now at about 1220.
The engine does have a small amount of blow by at times with exhaust coming out of the oil filler cap. It has had this for a few seasons.
I added 10 oz of MMO per 10 gals of gas and ran the engine in neutral at 1200 RPM's for an hour.
Rechecked TDC of #1 piston and rotor was positioned at #1 plug wire. Then check that order, going clockwise, is 1,2,4,3.
Tonight I got the boat out from the dock far enough to be in clear water and checked the prop and shaft underwater. There is nothing wrapped around it. The shaft turns freely in neutral. It does take quite a bit of force to shift into forward, but then the shifter has always been fairly stiff. With the shifter in forward, I can easily hand crank the engine and shaft.
The engine stalled 3 times in the ten minutes of running under load (may be the oil safety switch?). It runs fine at about 1/3 to 1/2 throttle, past that and it sounds like it's laboring and bogging down.
I'm out of ideas.
Comment