On Mon, 12 Jan 2009 10:17:27 -0800 (PST), stryped
wrote:
On Jan 12, 11:01*am, Andy Asberry wrote:
On Sun, 11 Jan 2009 18:02:58 -0800 (PST), stryped
wrote:
Been working on this engine. Took the carb apart as others have said.
Let it soak in mineral spirits and sprayed carb cleaner in passages.
Used can air to blow out passages. Had a heck of a time once I put it
on to get it to start. It seems that once it warmed up, I was able to
get it to finally run without choke after adjusting the carb what
seems to be hundreds of times. It helped that I had a battery charge
connected to my battery. (Once I disconnect the charger it seems to
not want to start).
I have a feeling that after it sits overnight, I wil not be sucessful
getting it started when it is dead cold. Also, it ocassionally
backfires and once made a loud pop out the exhaust.
I was worried maybe it did not have good compression was the reason
for trouble not starting. I did a test. Cranking with the choke closed
I got a reading of 50 psi, choke open 45 psi. Is this normal?
When I did take the carb apart the side adjustment needle with the
spring I noticed the end was flat. I can turn that screw with it
running and it seems to have no effect on the engine. Everything else
seemed ok the best I could tell.
Where can I go from here? It is starting to get frustrating.
Here is a short video of when I had it running. DOes everything "look"
like it is right?
SO do you think my 31380c rod in place of the 34750 rod was a sucess?
Here is a video of when it was warm and running:http://www.youtube.com/watch?v=h92ZPUMEB3Q
I collect and restore old garden tractors. There are two particular
pitfalls to these old cast iron Tecumsehs.
One is the Walbro carb. During manufacturing, the main jet is
installed in the carb body and THEN the passages are drilled through
the body and the side of the jet. Then the external hole is sealed
with a welch plug.
If you remove the jet, it is almost impossible to reinstall it with
the holes lined up. Replacement jets have a groove machined around the
jet so orientation isn't critical. You can file a groove in your jet
or chuck it in a lathe and machine one. Or get the replacement jet.
To clean the passages, some simply remove the welch plug, clear the
passage and install a new plug. That way the jet is undisturbed.
Number two is valve clearance. Specifically the exhaust valve. These
engines have compression releases on the cam that prevent the exhaust
valve from completely seating below about 600 rpm. This allows them to
be started with the small starter motors or ropes. Too much valve
clearance and the compression release can't do its job. It only cracks
the valve about 0.005".
With this info, you can see how your compression reading can be low.
To get an accurate reading you have to increase the valve clearance so
the compression release can't lift the valve. Better yet is a leakdown
test.
Give us the model and serial numbers and I can get you specs for your
engine.
Or join the Tecumseh group on Yahoo.
http://groups.yahoo.com/group/tecums...yguid=34062665
--Andy Asberry--
------Texas------ Hide quoted text -
- Show quoted text -
My model number is HH60 105116H ser 23230.
I am frustrated to the point of almost giving up. I cleaned the carb
twice but I did not take the welch plug out. I am starting to wonder
if it is just that the compression is not adequate. I honed the
cylinder and put new rings on. But I did not use ring expanders under
the 2nd compression ring. When I took the engine apart it did not have
them. I tried to install them but somethign did not seem right, the
piston did not want to go in the bore.
I used all new gaskets, torgued the head in sequence, cleaned
everythign, cleaned and gapped the points, timed the engine at .080
BTDC with a dial indicator. I put so much work into this. I dont want
to give up but I am wondering if I should just buy a new engine.
It seemed to run decent in the video once I got it warmed up. But it
took a battery with a battery charger hooked up and lots of cranking a
fooling around with the choke to get it going.
I feel defeated....
First, a correction: the mechanical compression release raises the
valve 0.050", not 0.005".
I don't have a manual for anything less than a 10 hp. The manual
doesn't give a psi reading for compression. They say to roll the
engine backwards. If it bumps against compression, that is enough to
run. I suspect they use this method rather than try to explain the how
and why of the compression release.
Have you tried cranking with the plug out? Does it spin easier? If so,
that indicates the compression release is not working. (A pin holds
the exhaust valve open until a centrifugal weight pulls it aside.) The
pin can be worn down.
Did you check the end gap of the new rings?
Are there numbers or letters on the carb?