rainedave

My Feedback: (1)

I just replaced the bearings in my OS FS 40 Surpass and I want to be sure I got the camshaft in correctly.

With the piston at TDC - marks on the drive washer and case lined up - I set the dot to be inline with the pushrods.

The photos show the two positions of the dot when the piston is at TDC.

Did I get it right?

Thanks,
David

Motorboy

Yes, with piston at TDC are the dot in right place in line with pushrods.

jaka

Hi!
The right photo is correct!...the left might also be correct ...but it's the right photo that OS refer to in its manual for their early 4 strokes

rainedave

My Feedback: (1)

Thanks y'all! Both photos are from the same installation. The camshaft only rotates 180° with one full rotation of the crank.

So, I'm sure it's correct.

David

Motorboy

Jaka..
No, left! The dot are angled a bit back against clock 11 and are in line with push rods as in the OS manual:

HOW TO SET THE CAMSHAFT TIMING
When replacing the camshaft, set the timing as follows.

1. Secure propeller.

NOTE:
If propeller is not secured, crankshaft may move
backward and correct timing cannot be set.

2. Turn the crankshaft so that 'T' mark on the drive hub may
match crankcase center line. (This is engine T.D.C.
position)

3. Push the camshaft into camshaft housing until it stops.
Locate ' * ' mark on the side of camshaft gear in line with
the push rod.

4. Rotate crankshaft right and left a little and make sure that
the ' * ' mark on the gear is in line with the push rod when
the ' T ' mark on the drive hub matches the crankcase
center line.

5. Secure cam cover with screws.

A note, the four stroke engines from Sanye such as SC, Magnum and ASP has ' * ' mark straight down against the helical gear at crankshaft. (MAN March 2008, "Engine clinic" about four stroke secrets by Clarence Lee)

Edit: Added pictures...

rainedave

My Feedback: (1)

Thanks Motorboy. That is basically how I did it.

In this photo you can see that the dot is at about 5:45 or so and is inline with the pushrods; it is not in line with a straight up and down axis.

David