I have a craftsman rider with a 15 HP Briggs 28N707. I replaced the
connecting rod and reassembled and it wont start. The connecting rod
melted onto the crankshaft but the crankshaft was OK and all else was
fine. piston was fine and cylinder was OK. rings were OK. I gets
spark. It gets gas. It backfires when I crank it. When I turn the
flywheel by hand I hear hissing from the cylinder like air escaping?
I set the timing gear and cam gear exactly with both markers aligned.
Is there another way to set the timing markers? Do I need to position
the piston in a particular location before aligning markers? I just
aligned the markers and set the valves? Please let me know if you
have good ideas.
You probably have the marks aligned 180 degrees out.
If correct, with the cam gear timing mark and the crank gear timing mark
aligned, both valves are closed. If the marks are aligned and a valve is
open, you need to remove the camshaft and rotate it 180 degrees.
Have a look here for the procedure to degree a camshaft:
FYI if your exactly 180 degrees out rotate the crankshaft 1 full turn and
your marks will line up ( cam makes 1 rotation for crankshaft 2 rotations.
so every other rotation of the timing marks show 180 degrees out)
Did you have the head off? if so did you reuse old gasket? if so the gasket
is shot and leaking?
do you have any comprestion?
are you sure you got the timing marks right? that is my first thoughts you
could be out a couple teeth I would start there.
Hi thanks for the email. I am trying to understand. I do not have
a degree wheel or dial indicator so I am going by sight which is
pretty good. However, your message seems to be saying that the
alignment marks on the gear and the cam may not necessarily be
touching each other. From what I have been told, I always assumed
that, the alignment marks simply needed to be adjacent to each other
so that they came as close as possible to touching each other. If so,
it would be properly aligned. But it seems that you are saying that
if a valve is still open when the piston is TDC and the marks are
adjacent to each other, there is still a problem and then the cam
needs to be rotated 180. That would mean that the mark on the cam
would be as far away from the mark on the gra as possible? Am I
understanding correctly? This is a revalation to me as I have been
toying at this for 6 months and from what I was told, the marks must
be adjacent to each other for alignment to occur? I am stumped and
perplexed. Please help if you can. I am still at the 3rd grade level
I don't understand what they are saying either... because the cam on a
single cylinder engine CAN'T be 180 out. If it was, then the timing
marks would be on opposite sides of one another! As long as the marks
are aligned, it's in time.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.