Export thread

After removing the oil sump (to replace a leaking gasket), I wasn't paying attention to what I was doing and the camshaft fell out.

My shop manual says to match the timing mark on the cam to the one on the crank.

The problem is, there is no mark on the crank gear. What is the proper procedure for getting this timed?

There is some information out there that says to bring the piston to TDC, and then to position the camshaft timing mark so that it is as close as possible to the crank shaft.

I'd just like to hear from the experts on this site before I do anything.

Surely I'm not the first to have this problem...

I just rebuilt my GXV140, and unless yours has a defect, there definitely *are* marks! One of them is a solid dot, the other an open circle at the base of the gear teeth that is very hard to spot, unless you kmow what you are looking for, and looks more like a scratch. Why they don't make them both the same, I don't know . . . Clean the gears thoroughly, and both should be visible . . .

To get closer and reduce your 'seek time', if you set the crank to TDC, and the cam with both lobes away from the tappets, that should be close, and I *think* that is the positioning when the marks align, but again, can't be 100% since I found my marks.

(I'd send a photo, but it's together and running now . . . my memory is telling me that the crank was the faint mark, but I may bave then backwards . . .)

- Tim

tadawson said:

I just rebuilt my GXV140, and unless yours has a defect, there definitely *are* marks! One of them is a solid dot, the other an open circle at the base of the gear teeth that is very hard to spot, unless you kmow what you are looking for, and looks more like a scratch. Why they don't make them both the same, I don't know . . . Clean the gears thoroughly, and both should be visible . . .

To get closer and reduce your 'seek time', i you set the crank to TDC, and the cam with both lobes away from the tappets, that should be close, and I *think* that is the positioning when the marks align, but again, can't be 100% since I found my marks.

(I'd send a photo, but it's together and running now . . . my memory is telling me that the crank was the faint mark, but I may bave then backwards . . .)

- Tim

Click to expand...

I thought I had looked pretty closely, but I'll look again. The only reason I took it apart is that the oil pan gasket was leaking underneath the cylinder casting. But I do notice some discoloration of the crankshaft around the area of the connecting rod. It froze last season due to low oil (due to gasket leak). I thought the engine was a goner, but when I went to remove the bolt from the shaft while removing the blade clutch assembly, the engine turned over. So I filled it with oil, and it started right up and was running fine. That's when I discovered the oil leak.

While you are that far in, I suggest you change all the oil seals - upper, lower, PTO, and gov shaft. On mine, they had gotten so hard that they were pretty much falling out (starting to lose a fair amount out the bottom, and the seal pretty much dropped out the end of last year . . .)Total cost, iirc, will be about $15 to $20 bucks, and it's a whole lot easier while you are there. Mine was smoking a bit, so I did a light hone and rings as well, and now as good as new, and almost no cylinder wear.

But yes, if you put the crank at TDC, the timing mark should pretty much directly be facing the cam . . .

Oh, and if the rod is torn up, the crank should clean and you can replace the rod . . . these commercial grade engines seem pretty hard to hurt.

bobster789 said:

I thought I had looked pretty closely, but I'll look again. The only reason I took it apart is that the oil pan gasket was leaking underneath the cylinder casting. But I do notice some discoloration of the crankshaft around the area of the connecting rod. It froze last season due to low oil (due to gasket leak). I thought the engine was a goner, but when I went to remove the bolt from the shaft while removing the blade clutch assembly, the engine turned over. So I filled it with oil, and it started right up and was running fine. That's when I discovered the oil leak.

Click to expand...

OK, after tadawson's suggestion, I went back and looked again very closely. And yes, Virginia, there IS a timing mark on the crank gear, although it is very, very faint. I had to use a sharpie to make it visible while putting the cam gear back in place.

Thank you, tadawson, for your help!

And thanks to everyone else who responded, too!

No problem, and glad you found it! All I can think is that since that gear is so thin and pressed on, that they made the mark as light as possible to avoid an origin point for stress cracking . . .

Hi
I had exactly the same problem and was really struggling to see the Camshaft timing mark, this post made me persevere and of course i found it, but i have attached a photo to show it in case others need some help !

it is very very faint !

WOW, that doesn't look factory at all. That's some serious macro on that camera. Makes the gears look pretty rough. Guess one should remark the gears before removing.

slomo

bobster789 said:

After removing the oil sump (to replace a leaking gasket), I wasn't paying attention to what I was doing and the camshaft fell out.

My shop manual says to match the timing mark on the cam to the one on the crank.

The problem is, there is no mark on the crank gear. What is the proper procedure for getting this timed?

There is some information out there that says to bring the piston to TDC, and then to position the camshaft timing mark so that it is as close as possible to the crank shaft.

I'd just like to hear from the experts on this site before I do anything.

Surely I'm not the first to have this problem...

Click to expand...

Here's an authoritative discussion I found online (grumpy on https://www.outdoorking.com/) of the reasoning behind Honda not putting timing marks on some crankshaft gears and a method for timing that doesn't rely on crankshaft gear markings:

"My system for getting by without a timing mark on the crankshaft timing gear, is I put the crankshaft on TDC, then insert the camshaft so that its timing mark is at the closest point of approach to the crankshaft. Of course you have to allow for the spiral gears, so you enter the teeth nearly 1 tooth anti-clockwise from where you want it to end up. I prefer to use a pair of timing marks, and that is why I make one before taking the camshaft out, but it isn't actually necessary, and isn't recommended by Honda. In case you care, the reason there is no mark on the steel crankshaft gear, is that it isn't keyed to the crankshaft, it is just pressed on. Honda recommends pulling it off and replacing it if if gets worn or damaged, so they couldn't have put a timing mark on it in the factory in case the owner later removed the gear and replaced it, in no particular position."

Well here's how you time this engine.


Now isn't this better than guessing?