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M5B 2 stroke - some issues

So I was all fat and happy rebuilding the water pump and carb. Have the factory manual, etc.

Somewhere I screwed up - at least the with carb I think, the water pump is doing fine...;>

1) For some reason when the motor is OFF, i can't shift into reverse. When motor is running, I can. I find that odd. maybe a slight adjustment of the shift linkage perhaps?

2) It starts and idles fine, when I try to give it throttle, the throttle slips - lever turns back down - i think the plastic thingy is worn - so that is no brainer.

3) When I do accelerate, it seems revs up - but then seems to stop revving fairly early and won't rev much beyond that - before I get to the start mark on the throttle lever. I don't have any meter to meaure RPM...I guess time to go to Harbor Freight to check what is going on..

4) Getting some smoke from the back, not excessive, but you can see the color when boat is not moving. Can't really see it when boat is moving. Perhaps too rich? Maybe I messed up the float level? argh....

5) Want to check timing. Is the timing adjustable on the M5B? I have the factory manual and seloc, both are not clear.

Factory manual only has this info re timing:

The magneto of the 5 engine uses an “electrical lead angle” where
ignition timing is advanced as engine RPM increases.
1. Start engine and check ignition timing using a timing light.
2. Two marking lines are cast on top of the flywheel,
topand lead angle: BTDC 30°.

this really doesn't tell you how to adjust the timing if it's not to spec....am I missing something???

6) Carb setting pilot adjust screw., Factory manual is not so clear. What is the "standard setting"?

Adjustment Procedure
• Tighten the pilot adjusting screw slightly, loosen it to adjust to the
standard setting. Set the specified RPM by regulating the throttle
and stop screw while monitoring the engine speed with a
tachometer.
• Set the pilot adjust screw to a position where the engine speed is
the highest within ± 1/4 turn of the reference position.
• Set the specified speed with a throttle stop screw.
Thanks...
 
Last edited:
1. Normal on all outboards. Either the driveshaft or prop must turn to shift into reverse.
2. You may need a new friction piece in the tiller handle.
3. Are you able to open the throttle plate, or does the linkage jam?
4. Probably normal for a 2-smoke motor.
5. The spark advance is hard-programmed into the CD, and varies with RPM. No adjustment needed.
 
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