I've had my 20B on a test stand all wired up and ready to run for
    months.  But even after endless troubleshooting I haven't been
  able to   achieve a successful start.

    Today I hooked up a compression tester and I?ve probably found the
    problem.  Rotors one peaks out at 35 ? 40 psi and leaks down the
instant
    I stop cranking the engine, rotor two peaks around 50 psi and
  leaks   slowly down, rotor three peaks and will hold about 60 psi.
  I didn?t own   a compression tester when I did the rebuild and
  figured since I replaced   practically everything but the rotors and
  housings I should be OK.

    Any thoughts, comments, or suggestions before I start tearing
  down the   engine?

    TIA

    Jay

    Remove the schrader valve from the compression tester and watch it
    while the starter turns the engine over. It should equal pulse 70
  to 80   psi three times in a row on each rotor.

    Sounds like you have one or more stuck
    apex seals. Remove the exhaust manifold and use a small screw driver
    to push on the apex seals through the exhaust port. If you cannot
    feel them move in and out under the influence of the springs you
    have a stuck seal. Spray WD40 in there and keep trying.
    Remove the plugs and put some auto transmission oil in the engine.
    Turn it over a few times and let it sit over night. Then check the
    seals again. Once you get it running it will clean itself up.

    Are you mixing oil with the fuel?

    Paul Lamar

  I have heard a few comments over the years of leftover carbon in the
  apex slots sticking seals after a rebuild. Do you recall any issues
  getting the apex seal springs inserted, that is a hint. As Paul says,
  pull the exhaust, check the apex springs for spring.  Try ATF in
  the plugs/exhaust, turn over the engine and work the apex seals manually.

  How bad was the edge flaking on the rotor housings you used?
  vendor seals?

  Cheers
  Cary

  Paul is right,
  One other suggestion, give it a squirt of ether as you crank.
  Milo

  My 20B sat for over a year before I tried to start it. It also had
  the seals stuck from sitting. I poured lots of ATF down the intake
  and let it sit overnight. Then spun it over the next day without
  plugs in it. I didn't run a compression check before hand, I've done
  enough of these I could tell by the sound what was going on. I spun
  the plugs back in and it fired right up. Smokes like hell for a bit.
  Don't worry about your leak down test. Rotaries don't fare so well
  with a leak down test. Too many places to leak. A piston ring has
  one leak down spot.(not counting the actual sealing surface, but the
  ring gap)  Rotor motors have at least 8, more if you want to get really
  technical. That's why cranking speed is very important. It cant have
  too much leak down time during cranking. More speed, less time. I'll
  bet you fire it up once and it will be good to go.

  Bob Mears


 What size battery cables are you using? While cranking it over, does a
cable
 or terminal get warm or hot? I would put a bit of oil in either the intake
 or
 remove the leading plugs and put a small amount of oil in. Spin it over
for
 a
 couple of seconds to spread the oil. Put the plugs in and try to start it.
 NOTE: you only want about a tablespoon of oil per rotor housing. When you
 rebuilt the engine, did you smear a bit of oil on the end housings and
rotor
 housings like you would in a cylinder bore of a piston engine? ATF is good
 as
 it will not "dry out" like engine oil will. Piston engines sometimes will
 not
 start well after they have been flooded. The gas dries the cylinder walls
 and
 the blowby increases. If it is cranking a bit slow, it will not start.
 Remedy
 is a little oil in the intake to seal up the valve seats and cylinder
walls
 long enough to start it.

 Like my buddies used to plead me to do when I had the worn out R100;
 Rotor...Do a smoky!

 Dale Davies

300 cranking amps is unlikely to be enough.  Even more, the reserve
(how much cranking you can do) is most likely smaller than you
should have.  Have you tried jumping to a car battery?

Dan F

I assumed you have checked the timing. Should be 22 degrees BTDC on
rotor one.

Paul Lamar



I just bought another larger battery Paul, I'm going to give that a try
before anything else.

Jay