Yamaha 2B Outboard

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SteveIOW

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I need to replace water pump impeller on my Yanmar 2B Outboard but am having problem with dismantling.

Have managed to remove the two bolts securing the bottom (gearbox) section to the leg above it. Have also drained the gearbox oil, removed the prop shaft bearing housing and removed the small circlip than retains the small bevel gear on the bottom of the drive shaft. So far, so good. Have managed to prise apart the bottom and leg sections by about 10mm but that is as far as it will go. What is stopping it coming apart? Could the drive shaft be seized onto the engine output shaft at the top of the middle section? What else could it be?

Need to get it sorted ASAP. Getting too old to row to the mooring!
 
SteveIOW said:
I need to replace water pump impeller on my Yanmar 2B Outboard but am having problem with dismantling.

Have managed to remove the two bolts securing the bottom (gearbox) section to the leg above it. Have also drained the gearbox oil, removed the prop shaft bearing housing and removed the small circlip than retains the small bevel gear on the bottom of the drive shaft. So far, so good. Have managed to prise apart the bottom and leg sections by about 10mm but that is as far as it will go. What is stopping it coming apart? Could the drive shaft be seized onto the engine output shaft at the top of the middle section? What else could it be?

Need to get it sorted ASAP. Getting too old to row to the mooring!
Click to expand...
Yes
You will probably have to invert the engine and try to get some release oil to run down the shaft and soak into the seized/ rusted joint for a few days or weeks

With the circlip removed from the bottom of the drive shaft too much brute force could wreck the pump housing. I would have not removed that until the gearcase was separated from the leg.

When you reassemble lightly grease the splines or IIRC just a square to stop it happening again
 
Steve
If you don't have the workshop manual for the engine, and you think it might help, I can send you a PDF copy, or you can download it from the internet.
 
VicS said:
With the circlip removed from the bottom of the drive shaft too much brute force could wreck the pump housing. I would have not removed that until the gearcase was separated from the leg.
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Thank you for the warning VicS. Unfortunately I had already tried a bit of brute force, and Yes, the pump housing has started to break up. Didn't achieve much either as the drive shaft is still seized on at top. Will have get a new housing before I can eventually complete the job.
 
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