03-13-2020, 10:47 PM
pekingduck, when I get a call from him I will ask, probably middle of next week.
However, as you note, 1-4 and 2-3 share coils. 1 and 4 are piston pairs, the pistons are both at tdc at the same time, as are 2 and 3. Automotive systems that share a coil between piston pairs have a waste spark occurring and the same thing happens here. I have a 90 horse 4 cyl Honda outboard that does the same thing.
That is why I agree with you that it is not staggered. I also think I would have lost more than 5 hp if that were the case. Also, why stagger the closing of the intake valves for effect then reset ignition timing to try to "fix" it? Not saying it couldn't be done, but I think it would require one coil per cylinder.
Any question could easily be answered by removing the timing cover and using a timing light to compare 1 and 4. If the mark is in the same place, timing isn't staggered. I never considered it a concern or I would have done that.
Also interesting to note is the manaul shows the firing order 1-2-4-3 rather than the typical 1-3-4-2 usually seen. However, this still makes 1-4 and 2-3 piston pairs.
Ben
However, as you note, 1-4 and 2-3 share coils. 1 and 4 are piston pairs, the pistons are both at tdc at the same time, as are 2 and 3. Automotive systems that share a coil between piston pairs have a waste spark occurring and the same thing happens here. I have a 90 horse 4 cyl Honda outboard that does the same thing.
That is why I agree with you that it is not staggered. I also think I would have lost more than 5 hp if that were the case. Also, why stagger the closing of the intake valves for effect then reset ignition timing to try to "fix" it? Not saying it couldn't be done, but I think it would require one coil per cylinder.
Any question could easily be answered by removing the timing cover and using a timing light to compare 1 and 4. If the mark is in the same place, timing isn't staggered. I never considered it a concern or I would have done that.
Also interesting to note is the manaul shows the firing order 1-2-4-3 rather than the typical 1-3-4-2 usually seen. However, this still makes 1-4 and 2-3 piston pairs.
Ben