The tach drive does have a seal, but normally the leak comes from inside the cable. One way of sealing the cable is shrink wrap (like you use for electrical wires. Then back it out and see if the rubber seal is on the inside of the cable. Lots are lost because of an owner removing the cable and pulling on the cable housing causing the seal to come off, then when they put it back in the seal pops out and is lost (parts book #17). So you are really looking for two seals, one in the housing and one on the cable.
Bill
> -----Original Message-----
> From:
> 2cylinderhondas@yahoogroups.com [mailto:2cylinderhondas@yahoogroups.com] > On > Behalf Of > jeffanson2005 > Sent:
> Friday, October 12, 2007 7:25
> PM
> To:
> 2cylinderhondas@yahoogroups.com
> Subject:
> [2cylinderhondas] Re: trouble starting engine after
> rebuild
> Yup! Bill game me a clue. Found some oil coming out of the tach > cable, > not speedo area. I need to check if there is supposed to be > an o-ring in > there.
> Also tach indicator jumps around (while tach should show around > 1000 > rmp its around 4000 then jumps in the red area while giving it a
> slight rev.) Dont know if thats a cable problem or tach
> itself.
> Jeff
> Miami, FL
> --- In
> 2cylinderhondas@ yahoogroups. com
> ,
> wrote:
> > Jeff;
> > Try looking at
> the speedometer cable seal. Many I mean many
> leak.
> > Also, check the
> torque on the 6mm bolts, including the one under
> the head.
> > All of
> them should be at least 90 inch pounds.
> > Bill
> -----Original Message-----
> > From:
> 2cylinderhondas@ yahoogroups. com
> [mailto:
> 2cylinderhondas@ yahoogroups. com
> ]On
> Behalf Of jeffanson2005
> > Sent: Sunday, October 07, 2007 3:38 PM
> To:
> 2cylinderhondas@ yahoogroups. com
> Subject: [2cylinderhondas] Re: trouble starting engine after
> rebuild
> > Hey all. Just an update about the engine
> problem we had and how we
> > managed to fix it.
> > With big
> help from excellent advice from Bill and Dale, we
> retorqued
> > the
> head to 30 ft/lbs and oil leak has stopped. A few drops are > > coming out > now, but havent located the exact position yet. Car was > > assembled > slightly off time where the cam wheel line was not > > horizontal when > setting the time. Once properly set we rechecked > > compression and now > have 180 drivers, and 160 passenger cylinder.
> > Much higher than I
> expected. I'll check it once a month during
> break
> > in
> period.
> > I'm a happy boy again now I can finally drive the
> Z.
> > Thanks again for all the helpful replies.
> Jeff
> > Miami, FL
> > 1972 Z600
> > --- In
> 2cylinderhondas@ yahoogroups. com
> ,
> "jeffanson2005"
> > wrote:
> > 1 if the battery is low it will not crank enough to start. Batt
> is ok
> > > and turns over engine easily
> > > 2 if
> it flooded out, it will not start, need to pull plugs and > dry
> out.
> > > Replace and try again. Plugs are nice and dry on both
> cylinders
> > > 3 check the braker plate to see if it is
> moving up and down ?
> > (this
> > > is a problem with points
> maintaining their gap) Gap seems to be
> ok
> > and
> > > moving
> normally
> > > 4 What did you torque (Ft. Lbs.) the head
> to? Torque was
> applied as
> > > Haynes manual states proper
> lbs
> > > 5 The engine leaks, did the cylinders have "O" rings at > the > > base of > > > the cyliner? Leaks can occure from the rear > of the engine > when "O" > > rings > > > are not replaced on the > early cylinders, later ones didn't use > > them.
> > > And, the
> shop manual doesn't show or talk to them. Did not
> notice
> > any
> O
> > > rings when we disassembled cylinders, but you could be right
> about
> > where
> > > the leak is coming from. I'll pull the
> fan off and turn over the
> > engine
> > > and see if I can spot
> any leakage in that area 6 Did you check
> > the
> > > spark plug
> wire ends to ensure they didn't come lose? The engine
> > will
> > not start if both plugs are not fireing. Yes, they seem tight
> and
> > > getting good spark 7 Did you change the cam chain? (use a > new > > one) > > > No. Used existing chain 8 when the head was > rebuilt, was it > > checked > > > to see if it was warped? No, but > had machinist check for > anything > > > abnormal and all was ok. 9 > when replacing the head, were cap > > nuts > > > used on the rear > center studs? Not sure. I'll look and see 10 > > When > > > you had > the cylinder bored, how many thousands over the piston > size
> did
> > > you bore them to? Good question. I left that to the machinist
> and
> > gave
> > > him all the specs from the Haynes manual. 11
> When you put the
> > > pistons in were they put in with the IN mark
> toward the intake
> > valve?
> > > Arrow on new pistons (1mm os)
> pointing forward as per directions
> > from
> > > manufacturer of
> new pistons. got them from O'connors. 12 did
> > you
> > > use
> factory gaskets? Somewhat. O'connors sent us sheets with
> printouts
> > > on the gasket which we had to cut out ourselves and
> seemed to
> be ok,
> > > however we did not get a gasket for space
> between cylinders and
> > head, so
> > > we used the one that was
> already there checked compression today
> > and
> > > got nothing
> on either cylinder. thinking the whole thing is out
> of
> time
> > > and possibly valves are open when they shouldnt be and or > oil > leak > > is > > > cause of not having any compression.
> Since engine did run right
> > after
> > > I filled it with oil,
> I'm thinking the oil had something to do
> with
> > > giving the
> engine some compression while it was coming through
> the
> seams. Thanks for the help! You guys sure know your stuff. Hope
> to
> > > remedy this soon.
> > > --- In
> 2cylinderhondas@ yahoogroups. com
> ,
> "jeffanson2005"
> > > wrote:
> > > Need some guidance with getting my 72 Z600 to fire. Recently
> rebuilt
> > > > the top end of engine after having a valve bury
> itself into my
> > > > drivers side piston. Had the cylinders
> machined and bought 1mm
> > > > oversize pistons from Oconnors.
> Brass valve sleeves from
> Miles and
> > > > some other items from
> here and there.
> > > > Got the engine to start, but ran really
> rough and had little
> > power.
> > > > I had a tow truck on the
> way to pick it up and take it to
> another
> > > > shop for a
> custom exhaust system to be installed. I ran the
> car
> > for
> > > mabey 3 or 4 minutes and when I parked it outside I noticed > a > > large > > > > amount of engine oil coming out after I had > turned the engine > off.
> > > > Didnt have time to mess with it
> but it seemed to be coming
> from
> > the
> > > > rear of the
> engine say around the cylinders and near the fan.
> > > About two weeks later the car returned with the new exhaust > in > > place > > > > and I proceeded to inspect where the oil > leak was from but > could > > not > > > > start the engine > again. I check the timing, static, pulled the > > spark
> plugs and I'm getting a nice spark when trying to start.
> Pulled
> the
> > > > carb to see if there was any flooding involved, but
> didnt
> notice
> > too
> > > > much fuel in the manifold. I'm
> getting fuel up to the carb
> and can
> > > > smell it when I'm
> trying to start with the aircleaner off. I'm
> > > > assuming fuel
> is getting into the carb.
> > > > Many experts on
> this forum could give me the basic things to
> check
> > > > for
> to get the engine to fire. Hope anyone could help. It
> would be
> > > greatly appreciated. Tomorrow, I'm checking for proper
> compression
> > > > on each cylinder. Any other tips would be
> great.
> > > > Engine cranks but does not
> fire.
> > [Non-text portions of
> this message have been removed]