Post by: M on May 18, 2015, 01:52:35 AM
This was my very first time to tear into an engine.
My riding mower started to smoke really bad, and common consensus online is that its the head gasket. Very common issue with this engine.
Took old one out, put in new head gasket and put it all back together. I really struggled with finding the correct position of the rods and when to measure the valve gaps.
When I tried to start it, the motor would spin about 3/4 and then stop. It will not start. Did I fuck up the rods and valve gaps, and need to redo it? Whats the trick in this area?
Post by: M on May 18, 2015, 02:43:48 AM
Here's a time lapse video I did: https://youtu.be/sMHfV5j6PSU
Post by: mr.mindless on May 18, 2015, 09:26:18 AM
Are you certain the lifters and pushrods are fully seated? Most common cause, and how I bent a pushrod in my truck after having rockers off.
Post by: M on May 18, 2015, 10:38:30 AM
if you can't turn a motor over by hand, NEVER try to start it.
I was able to move it over by hand when I put in the push rods and rockers. Then when I tried to start it, I can't move it by hand.
Are you certain the lifters and pushrods are fully seated?
No. How do I determine this? Before I mounted/tightened the rockers, I spun the motor by hand and both pushrods moved freely.
Post by: rejeep on May 18, 2015, 10:57:49 AM
I was able to move it over by hand when I put in the push rods and rockers. Then when I tried to start it, I can't move it by hand.
no bueno
Post by: mr.mindless on May 18, 2015, 11:33:16 AM
They probably fell out when you rolled over the engine without rockers.
Tapatalking in traffic
Post by: M4wdFab on May 18, 2015, 11:40:37 AM
Post by: M on May 18, 2015, 12:09:59 PM
Take the rockers off. Reseat the pushrods in the tappets. Put the rockers back on.
They probably fell out when you rolled over the engine without rockers.
I said the wrong thing. I did test the motor when the rockers were on it and was able to spin it by hand. It's 1:25 in the time lapse video when I was moving the cylinder to try to find 1/4 past the top stroke so that I can adjust rockers to spec.
Post by: mr.mindless on May 18, 2015, 12:52:32 PM
Readjust.
Watch for one to move while the other doesn’t. Set lash on the one that is closed. Easy. Especially when you’re not dealing with trying to optimize work on a 6 or 8 cyl engine that’s a pain to turn over.
Tapatalking in traffic
Post by: M on May 18, 2015, 08:20:09 PM
When the spark plug was inside the motor, I couldn't turn by hand. When I removed spark plug,I was able to turn by hand easily. Took a few times putting spark plug in and out adjusting rocker gaps until I was able to turn it by hand.
Post by: JEEPWERX on May 19, 2015, 08:17:22 AM
where is the quote where i say rebuilding motors is for the birdsI really enjoyed the challenge and the work itself when I rebuilt my first 258 that's in my street jeep.
Very detail oriented project compared to building a house.
Glad to hear you got it running.
Post by: mr.mindless on May 19, 2015, 09:18:26 AM
it was hitting the plug?
Or was it too much compression for you to overcome however it was you were turning it?
Post by: M on May 19, 2015, 09:31:04 AM
Post by: mr.mindless on May 19, 2015, 09:36:18 AM
There should be a spec, probably .007-.010" for intake and .018-020" for exhaust. I'm worried that they were adjusted too far if you made a notable difference in compression.
Post by: M on May 19, 2015, 10:34:44 AM
Post by: TrailTamer on May 21, 2015, 09:08:02 PM
Spark plug back in, started right up, but run funny.
I stopped it and drain the motor oil. I made a huge mess on my driveway because there was at least 1/2 gallon of oil/gas coming out and I had a jar that wasn't big enough. This is with a 14HP I/C B&S, it wasn't suppose to have that much oil (and gas).
New oil and fuel shut off valve, no more smoking exhaust. I'm back in business.