Hi to all you knowledgeable folks.
Amongst the collection I have a small Wolf Garten Scooter ride-on (yes I know, maybe a bit of a toy but still immensely useful in tight situations). It needs a new engine - main casting catastrophically broken around the upper main bearing. The existing engine is a Tecumseh VLV60 502045D: Vertical crank, single cylinder, electric start, 207cc, 6HP. I know about Tecumseh ceasing small engine production, I've had a bit of a hunt around without success and I don't hold out much hope of finding one of these engines ready to fit. So, now I'm looking for an alternative from another manufacturer but it seems that this engine has a non-standard output shaft. Details of the shaft are:
Length: 86.2mm (from engine mounting face to end of shaft)
Diameter: 22.2mm (7/8")
Keyway: 4.75mm wide (3/16") (19.45 from base of slot to other side of shaft, so probably standard)
Internal thread: 3/8" x 24TPI, approx 25mm depth of thread
So, as far as I can make out this seems to be pretty standard except for the shaft being around 6mm longer than the longest standard shaft I've found so far (being 3-5/32" or 80.2mm). Unfortunately the shaft does need to be this length as it drives firstly a vee-belt pulley (at the top of the shaft) for the traction drive and a friction clutch (at the bottom of the shaft) for the cutting blade drive. The axial compression of the clutch during assembly is done by the bolt mated with the internal shaft thread. The overall height of the vee-belt pulley/clutch assembly is governed by the shaft length and so the long shaft is important. It may be possible to use a more standard engine with a 80.2mm shaft and to introduce a simple 6mm spacer at the end of the shaft but this would mean that the axial bolt has substantially fewer threads engaged and might just be likely to fail. Of course this could be fixed by using a longer bolt having the correct large head diameter (and presumably forged for strength??)
Does anybody have experience of this sort of problem? As far as I can see the best solutions would be to either:
1. Find a standard new engine with a longer than usual shaft, or
2. Use an engine with a standard shaft length together with a suitably robust modified spacer/bolt combination.
In terms of physical size, the Briggs 8.75 gross torque unit would just about fit in the space available with very little clearance on all 4 sides and with about 40mm space above.
Any assistance/insights/wisdom gratefully accepted.
Thanks in advance.
Amongst the collection I have a small Wolf Garten Scooter ride-on (yes I know, maybe a bit of a toy but still immensely useful in tight situations). It needs a new engine - main casting catastrophically broken around the upper main bearing. The existing engine is a Tecumseh VLV60 502045D: Vertical crank, single cylinder, electric start, 207cc, 6HP. I know about Tecumseh ceasing small engine production, I've had a bit of a hunt around without success and I don't hold out much hope of finding one of these engines ready to fit. So, now I'm looking for an alternative from another manufacturer but it seems that this engine has a non-standard output shaft. Details of the shaft are:
Length: 86.2mm (from engine mounting face to end of shaft)
Diameter: 22.2mm (7/8")
Keyway: 4.75mm wide (3/16") (19.45 from base of slot to other side of shaft, so probably standard)
Internal thread: 3/8" x 24TPI, approx 25mm depth of thread
So, as far as I can make out this seems to be pretty standard except for the shaft being around 6mm longer than the longest standard shaft I've found so far (being 3-5/32" or 80.2mm). Unfortunately the shaft does need to be this length as it drives firstly a vee-belt pulley (at the top of the shaft) for the traction drive and a friction clutch (at the bottom of the shaft) for the cutting blade drive. The axial compression of the clutch during assembly is done by the bolt mated with the internal shaft thread. The overall height of the vee-belt pulley/clutch assembly is governed by the shaft length and so the long shaft is important. It may be possible to use a more standard engine with a 80.2mm shaft and to introduce a simple 6mm spacer at the end of the shaft but this would mean that the axial bolt has substantially fewer threads engaged and might just be likely to fail. Of course this could be fixed by using a longer bolt having the correct large head diameter (and presumably forged for strength??)
Does anybody have experience of this sort of problem? As far as I can see the best solutions would be to either:
1. Find a standard new engine with a longer than usual shaft, or
2. Use an engine with a standard shaft length together with a suitably robust modified spacer/bolt combination.
In terms of physical size, the Briggs 8.75 gross torque unit would just about fit in the space available with very little clearance on all 4 sides and with about 40mm space above.
Any assistance/insights/wisdom gratefully accepted.
Thanks in advance.