Recent content by Boffin

  1. Boffin

    Should I replace my old Yanmar motor mounts with OEMs or a newer design?

    In my 1GM10, the manual spec.the hardness of the engine mount is 70 near the gear box, while the other two is 50. I think it is adopted to reduce the vibration due to the shaft connection. I don't know whether it applies to 2GM. my friend recently replaced all mounting of his 3GM30.It looks good...
  2. Boffin

    More Yamaha 25 prop shaft Questions

    it works OK.
  3. Boffin

    More Yamaha 25 prop shaft Questions

    The OD of the cutlass bearing is 11/4 while the shaft is 7/8 . my boat was 25 mark 1 built in 1977.The length of the strut is 4 inches but most of the available cutlass bearing is 31/2. it works on.
  4. Boffin

    P = 97 on tachometer

    if you don't have an extra tachometer for calibration, set the VDO tachometer to pulse mode ,then set p=97. That would be OK. The flywheel of Yanmar 3GM given 97 pluse per rev.to the sensor then to the tachometer as reference. or you can go to the adj mode to cal by an individual tachometer ...
  5. Boffin

    P = 97 on tachometer

    It means the meter count the sensor from the engine of 97pulse per rev.. yes you have to set the tachometer at pulse mode of 97/rev.
  6. Boffin

    Yanmar YSM8G -engine racing w/ lots of smoke

    I have experienced this due to too much lub oil was filled. Then the engine racing with a lot of white smoke.I needed to plug the air intake to stop the engine. Taken out the excess oil and the engine resume normal. It is likely that the excessive oil affected the governer.
  7. Boffin

    Yanmar 1GM10 water pump impeller

    GThe engine mount is by Yanmar ,that comes with the engine.
  8. Boffin

    Yanmar 1GM10 water pump impeller

    The 1GM10 has two weakness . The impeller of the water pump that I have mentioned, better to replace it at every 300 hours. Next is the VDO hour meter in the panel . It failed after 90hours, search in the forum found out it is common on most Yanmar marine engine with VDO meter. It is bad, I then...
  9. Boffin

    Yanmar 1GM10 water pump impeller

    Here comes the picture. Pl note that you need to replace the propeller, the 1GM10 is R turn. Or you may need to adj the length of the shaft because of the new position of the engine.
  10. Boffin

    Yanmar 1GM10 water pump impeller

    Hi ,I am back. To fit a 1GM10 into the Y-25 ,you need to modify the engine bedding in the bilge . The original are two beam shape protuded on both side the bilge. You need to fix two strips of steel plate in the original bedding so the new engine seat can rest on it with the fixing bolts in...
  11. Boffin

    Muffler for Yamaha 25

    I have the YSM8 before , at that time I got a local made top in, side out muffler by stainless steel .
  12. Boffin

    yamaha 25 keel

    I fixed the transducer next to the sea water intake on the port side . It is some 1.2 m (3.9 feet) from the bottom of the keel. There may be some various depth of the keel . To play safe , you can allow the draft ( 5.5 feet)of the boat as the distance from the bottom of the keel to the...
  13. Boffin

    Yanmar 1GM10 water pump impeller

    The deep groove indicated some misalignment during installation. Yes , it is simple to reverse the cover plate. But the broken impeller after 240+running hours is not acceptable . The water pump in my previous YSM8 last for 12 years required no replaceemnt .
  14. Boffin

    Yanmar 1GM10 water pump impeller

    The water pump in my newly installed Yanmar failed after 240 running hours. The impeller was broken into several small pieces , and a groove of 0.5mm depth was formed in the brass cover plate . It is rather unusual for such short running hours, I suspected that the direction of the impeller...
  15. Boffin

    YSM 8 riser nipple, Y25

    If part 16 in your engine is 8-9" long , stay with it . It has the reason . My 25 original came with the 2.5" part 16, I found the sea water in the exhaust pipe l flow back to the cylinder head causing corrosion in the lower elbow and the cylinder head. It is because the opening of the exhaust...