Dave's 1650 Project - Page 57

CC1650Dave · #**561** 11-13-2011, 08:39 PM

Ah, I found the .035 in the K341 Owners Manual...

Sugarmaker · #**562** 11-13-2011, 08:43 PM

Dave,
Darn, sorry for the extra work on that item. Need someone who has had this problem or missed a timing mark to jump in here.
So lets see if you did pull the engine, which is a pain but not the end of the world. (I had to pull mine back out for the wiring re-do.) Then you could pull off the pan and check the timing mark right? Can you see the marks with the pan off? I have forgotten already!
Hey could the hard starting be from the compression release not functioning? That is part of whats supposed to make them start easier! Dave did you see this compression release functioning when the head was off? Its a little mechanical lifter.
I was able to see it work and raise the valve just a little, to release some of the compression. Just a thought?

Regards,
Chris

Sugarmaker · #**563** 11-13-2011, 08:49 PM

Dave
Just some random shots, I am sure your documentation is better than these. Maybe you can see the compression work when the cam cover is off? Grasping at your straws now!
Regards,
Chris

CC1650Dave · #**564** 11-13-2011, 10:19 PM

Chris, it wasn't a big deal to check the cam cover, because the K321 is the broken down motor originally from the 1450, and it's sitting on the bench.

I think you're right, that all I'd need to do is remove the oil pan to see, if it comes down to having to pull the K341 to check those timing marks. The problem will be getting the engine in any kind of position for me to look up in there. I'm really, really hoping I don't have to do that...

I don't remember for certain that the compression release was working correctly, but I'm pretty sure it was. I don't know how it couldn't be, right? That's all built into the cam. Besides, if it wasn't working you could expect the engine to turn harder, but not all the backfiring and all that.

Matt G. · #**565** 11-13-2011, 10:24 PM

If the ignition timing is correct and it's still backfiring through the carb, then I'd say the cam is retarded one tooth, so the intake valve is open further than it should be when the spark plug fires. You seem to have exhausted all other possibilities at this point.

CC1650Dave · #**566** 11-13-2011, 10:52 PM

Speaking of Matt, I was just doing searches looking for solutions, and I found this bit that you wrote last year:

Quote:

Rotate the engine to TDC with the head off and rock it back and forth. The valves will either not move at all or will rock slightly as you wiggle the crankshaft. If they wiggle and one valve is open more than the other, then you are probably off a tooth on the cam.

You may have even said something to that effect here and I forgot about it. This looks like the easiest way for me to check this without pulling the motor.

You still think it's a good way to tell? I don't quite understand the mechanics behind it, and wonder if I'll really be able to tell if one valve is higher than the other...

Matt G. · #**567** 11-14-2011, 06:37 AM

Worth a try...if it's inconclusive for you then you can pull the engine and check that way. One of the two possible TDC positions has the valves slightly overlapping, i.e. one is closing and then the other immediately opens. They should both be equally closed with the piston at TDC. If one is open more than the other, and/or you can tell it's opening too early or too late, then the cam is definitely off a tooth.

Sugarmaker · #**568** 11-14-2011, 12:59 PM

Dave,
Matt is much better at this than me. But I asked my son and he said at TDC the valves should be seated and they should have slight clearance between the valve and the lifter. In other words a feeler gage could slip in there. So maybe pull the head, open the valve cover and check what Matt is suggesting.
Good luck. Let us know. Wasnt this the one that you had the crank in and out several times getting the end gap correct?
Regards,
Chris

CC1650Dave · #**569** 11-14-2011, 01:52 PM

I did re-check valve clearances the other day, and when at TDC the spaces were there (of course) What I didn't do was rock it back and forth and see how the valves moved. I guess that's what Matt's suggesting.

And yeah, I probably put that crank back in five times trying to get the bearing plate spacing right. And each time I stared at those alignment marks until I was cross-eyed. You can really drive yourself crazy with such things. That's why I'll be so dismayed if I did, in fact, misalign them.

Sugarmaker · #**570** 11-14-2011, 05:03 PM

Dave,
Not sure on the rocking thing? I will be watching to see how that works.
In a V-8 engine, or maybe any engine, backfiring can be a indication of timing problems.
Regards,
Chris