Tune Ups
"Well Nick how do I do
my own tune up on my …?"
"I would suggest
purchasing a Owners manual or even better a Workshop manual and following that
!"
"No I haven’t got one,
so you must help me.."
By this time my eyes start
rolling and I feel Nauseous. There are writers getting paid loads of money
(unlike me) to try and show the biggest moron on "How to…" and some
dimwits are too cheap to purchase said literature. Sorry I can’t help you- buy
a Horse, actually I could be dragged into court for cruelty to Animals, by
making such a suggestion to certain individuals.
What I will do for those of
you more technically inclined is try to explain how it works and the Logic
behind all this plus little tricks. And for those of you preferring to keep the
posterior planted in their upholstery, some further wisdom to add to your
collection.
Most idle Airscrews meter
more fuel as they are turned out, so a good starting point is 1.5 turns out
from LIGHTLY seated . Well from your manual you can see how to set up initial timing (normally between 5-10 deg.), please in 99% of all cases this is done
with vacuum disconnected. See that you have enough oil in the motor and Oil
Filter. And "slinger away". If it Fires through the carb, your Dizzy
is probably 180 degrees out. If it pulls the starter dead, you have too much
Advance or were too cheap to buy a healthy battery. If it just starts to catch
but then runs really Ill you are too retarded (sorry your timing is). Once
started let her warm up at 2000 Rpm and then set up timing as by the book. By
ear you can normally advance timing until she runs real smoothly and any more
timing does nothing. Some say best timing has the most manifold vacuum.
Thereafter turn the Idle richer at idle speed, until you achieve the highest
rpm with the Mixture screw and then go ½ turn back. Set idle again, and if you
really want to be meticulous redo the timing procedure described previously.
Timing and Mixture go hand in hand.
Solid lifters can be
adjusted as follows, if you have no specs. Start at about .15 gap all round and
warm up the engine. Then back out each screw by 1/8 turn run and repeat the
screw turning, until you can just start hearing the tappets. This should be all
right for that cam, but see if your exhaust and Intake valves all have the same
lash and if not set them all to the tightest and then redo the procedure of
listening to noisy tappets. Normally the In. valves first make a Noise and then
you only carry on with the EX. Rather go loud than soft on valves- remember
that mistakes only crop up later and could cost you a Burnt valve or replacing
worn parts.
If your hydraulic valves
are adjustable, this is the way us old-timers do it:
On a warm Motor (Oil Temp
above 180 F) which is running, make sure all valves are Silent, otherwise find
the noisy one and screw down onto the Lifter until it shuts up.
Then each Follower gets
loosened until the Valve starts ticking and then SLOWLY turn the follower down
1/2 to 1 full turn. This you do for all valves.
Again set timing and idle
mixture as you have no specs. Right ? Hopefully by now you will have called CNA
for a Manual or asked the Engine builder for specs.
Problem being timing and
mixture are very correlated. The leaner you go the more Advance you can give-
at least until the Piston melts. Now you can tune the rest of the system. Get a
looooong gradual hill and accelerate up it in the tallest gear your motor can
pull. First at ¼ throttle and note if the engine pulls smoothly or pings etc.
by the way if the Motor is not really healthy, don’t bother ! When the Motor
runs out of steam or a fraction before redline (5500 Rpm at 6000 Redline), rip
your foot of the accelerator and cut the ignition. Now turn out all plugs and
compare them to one of the handy charts provided free by your Friendly Spark
plug distributor. Peering down the insulator with a Loupe and strong light you
can see a Brown ring forming advising you whether she is running rich or lean,
in the middle is about right- adjust the carb if you are out. Then repeat the
run at the same procedure until the plugs read right. Then give your
distributor 2 deg. More advance, make the run and inspect the plugs. Repeat
until the plug shows trouble or the vehicle pings- of course you are making
notes all the way. Then go slightly back on your adjustment for safety. Repeat
this procedure for ½, ¾, and full throttle.
Peering at your exhaust tip
does not do much in the way of Rich or lean, and much less if you have a hole
down the pipe and nothing at all if you run unleaded. Normally you can hear a
Motor whistle if it runs to lean or it may pop through the carb. If your Motor
runs rich enough it will Blubber like a brides Mother. When your Motor sounds
like a loose timing chain- that is detonation (normally a Engine only does that
shortly until it comes to a final rest, so you are unlikely to come into much
enjoyment of this kind of noise). Low Rpm knocking noises show too much timing
and if the motor runs flat it is too lean, not good for Bearings etc. but it’ll
take time to rattle your Motor to death.
Ah yes, the infamous Manual
and those Afraid to read it. COLD means just that-3 Hours after Engine Shutoff
on a Cold Winters day- or for me the Morning after the Car stood overnight.
Engine warmed up and Vacuum of does not mean that it can run on choke with the
vacuum canister pulled wide open and you subtract those degrees from your
present timing mark to calculate timing hot. You did not get the past sentence
? Good, neither did I, but I heard somebody do it that way ! By the way your
vehicle has a certain timing position at idle (at least piston #1 has just
before TDC). Then it has a certain advance on vacuum (easy suck the canister
open and check your advance with a light) and then a certain amount of advance
at certain revs. If these are out- you have a problem and if your local
mechanic tells you differently, consult someone else!
You want to know how to
adjust your points and Condenser quickly and effectively? Easy, buy an
Electronic Ignition!
You have more chance in
getting a response from Home affairs, than asking me for advice on a problem
that can be solved by a workshop manual. Said manual is probably the cheapest
way to extract the most power with the least Fuel consumption from your Motor.
Read it apply it and you will smile.
Since I am getting quite a
few requests on weird problems plus tune-up solutions, I have thought up the
Following:
Write me the nature of your problem
to Box 21469 Windhoek, e-mail me or Fax Windhoek 216883. I will then publish Question
(no I wont mention your name unless you think that is the way to Stardom) and
my Comment. Actually all I want to test if these Individuals with the quick
dialling finger are just as handy with the pen!
Now, if you want
to read more of my Personal comments (who
would ?), please hit