Egil wrote:
I wouldn't say the metering unit shuttle is a particularily complex item,
on the contrary it is quite simple. It does, however, involve a couple of
high precision parts with minute clearances.
I've never seen any failure og the internal parts of the metering unit,
and I'm really unsure whether they can be repaired as such, other then
by replacement.
What DOES fail, however, is the external vacuum control contraptions.
Some failure points:
1. Vacuum leaks.
2. Leaking diaphgram.
3. Breakage of the small plastic parts connecting the diaphgram
to the cam roller.
None of these could of course never have anything to do with fuel
lubrication properties.
These are all easily repairable.
> If any internal component fails, the entire unit must be
> dissassembled, repaired and relcalibrated. The latter is the tricky
part.
Not really, it is in fact pretty easy to do.
It involves a reasonably accurate vacuum meter, a common feeler gauge,
and a couple of pices of plastic tubing, including a T-piece.
The first time I tried this I had an arrangement that also involved
using a vacuum pump and a valve. I soon discovered I had more control
simply sucking with my mouth, and using the tongue placed over the end of
the tube as a valve!
Egil,
This is great to hear! Thanks for sharing this and I would love to get
more details on how one may recalibrate the metering unit. I may be naive
enough to take at face value the "warnings" expressed by others concerning
unleaded fuel and repairs to the PI system. Right you are about the Lucal
manual NOT mentioning anything on leaded fuel requirements. Nor does the
owners manual. It just suggests using 4-star or 97 RM grade pertol.
There is talk about one of the list members creating a web page for PI
owners. One of the major contributions to that page would be the knowledge
you have about the PI system and keeping it running. We all would sure
appreciate passing any tips and techniques on to your fellow PI owners.
Thanks,
Dave,
San Diego,
1970 PI TR6 CP51649
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