Ali, why are you changing the oil every 125 miles? The first time you change the oil after the rebuild was at 62 miles. Did you consider that the grits you found could be left over from honing the cylinder or lapping the valve during rebuild? By using the paper filter to filter the old oil, how is that going to remove the acids from by product of combustions that have saturated the oil?
The manufacturer recommend oil changes to replace the oil before it looses it's lubricating qualities and becomes thick from saturated acidic particles and unburn gases. It is not worth it Ali to filter your own oil unless you have a veriable speed centrifuge.
________________________________
From: Ali Khan <ak6666666@yahoo.co.uk>
To: Honda-C70@yahoogroups.com
Sent: Thursday, June 14, 2012 9:40 PM
Subject: [Honda-C70] Home Oil Filtering made simple
After getting new rings, piston (#150, the largest size), crank shaft bearings, con rod and new oil, I took out oil every 200 km (first drain at 100km) and filtered the oil and reused it.
1000 km running in done and completed. Good compression. Bike engine must be so happy on getting clean filtered oil every 200 so km. Found grit in oil at first 100 km change.
I have two white paper filters, one thin, one a bit thicker. Each is placed in a funnel over a plastic bottle. Bad oil passes first through thin filter. Then its passed through the thicker paper filter. Whole process takes over one day, about two days. I need to change filters when flow becomes too slow. The filter paper I found cheap A2 sheets (5 sheets per dollar) and I cut it into A4 sheets, folded it and placed in the plastic funnel.
By going this filtering, I can use oil (20w50 and straight 50) for more than 1000km, maybe 2000km (by adding a dash of stp).
Funnels are covered by polythene to stop dust from falling into oil.
I feel proud of myself.
Im still thinking of putting magnet on drain plug but it has not worked so far. Magnet is too large for the plug even after some grinding of magnet.
Ali Khan
Lahore, Pakistan
45 degrees C (114F) in heavy snail pace traffic
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1970-73 C70 Honda Service Manual: http://tinyurl.com/6ebwtw
1970-73 C70 Troubleshooting Guide:
http://tinyurl.com/6ebwtw (scroll to sec.7.1 page 101.jpg)
1980-83 C70 Honda Service Manual: http://tinyurl.com/hu42c
1980-81 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec.18-1 page 170.jpg)
1982-83 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec. 20-28 page 205.jpg)
1980-81 C70 Maintenance Schedule: http://tinyurl.com/z4zn6
1982-83 C70 Maintenance Schedule: http://tinyurl.com/hw35c
More resources for C70 Passports and Cubs:
http://www.shlaes.com/Vehicles/Scooter.htm
http://www.velodrome.com/HondaC70/HondaC70.html
