Did my timing chain come off?

[Gwbarm]

Yes you should definitely replace that, I would get a new part for that replacement.

[p5200]

I think I'll go out and see if I can remove the bolt and pull it out.

[p5200]

I got the guide off that the tensioner pushes against. After looking it over, it looks like it is all there. The one on the right side is pushed in a tight slot at the bottom. It's really tight I don't know what is holding the top of it. I think that's the piece that is broken so I've got to figure out how that comes out.

[Mech]

That second one goes up to a "T", which fits into a slot in the top of the barrel, under the head. You have to take the head off to get that out.

I wouldn't necessarily say that the slippers need replacing just because of those two strips of rubber. They sometimes have bits of excess rubber hanging over the sides of the steel backing that can get worn through and drop off like that. I've seen it before. First up, is the one you got out damaged ? Is the rubber worn thin in the middle of it's length ? Are there grooves where the chain's worn ?  Then, I'd try looking down from the top at the fitted one, with a light at the top or bottom, and look for deep grooves where the chain links wear, or bare metal showing on the slipper, or chunks lifting off the steel backing. If those strips had torn/lifted off where the chain rubs, there would be more of it, those wouldn't be the only bits and there'd be lots of rubber chips and mess. Look for the sort of wear and tear that would be expected if the slipper had worn right down to the self destruct point..

I'd check the chain for wear and consider replacing that, and the tensioner, but honestly, I've fitted lots of chains without changing those slippers.

[Gwbarm]

Good to know that, I have always just replaced them, figured age and oil soaked for years would cause the rubber to disinegrate. 

[Mech]

It's not really rubber.

The straight one that's on the tight side of the chain is really just to stop the chain from getting into a rhythm that causes it to flutter and twitch like a fan belt does at certain revs. It hardly touches the chain.

[p5200]

I found these little slivers on metal down at the bottom where the little screen was at. The timing chain to my eyes, looks to have a lot of wear on the inside where it wraps around the sprockets. The chain I ordered is suppose to be here tomorrow and the nut is suppose to be here by the weekend. Thanks a lot for the help folks.

 

[p5200]

I think I will try the guides like they are since the most important one looks pretty good. I thought about taking the tension adjuster out before, putting the chain on. I guess I should adjust it all the way down before I go to put it back in though.

[Gwbarm]

Good, was going to mention looking for little chunks of rubber in the engine, but I figured you would do that. Good you got your parts coming let us know how you come out. Yes, if Mech says they are good, they will be fine. 

[Mech]

If that's all the metal in there then it's a good one ..  haha.

See in the picture of the slippers on page two it looks like those bits of rubber could have come off the outer edge of the fixed slipper, and it could have happened just as the chain came off.. especially if the bits were laying there under the slipper and hadn't been washed away by the oil..

[p5200]

I'll post when I get it done if, the nut will go on lol! I drug my fingernail across the threads on the shaft and there seems to still be threads all the way. The nut though, is practically smooth on the inside I'm assuming it is a little softer material then the crankshaft hopefully,

[p5200]

Anyone know what size Allen wrench it takes to remove the large timing plug in the left side crankcase cover? I got the top smaller plug out. Thanks!

The Honda trx300ex

[Mech]

It will be a metric size, and a whole figure, no fractions. Use a ruler. 10, 12, 14, 16 are all common sizes..

And.. you can buy allen key tools that fit onto ratchets or power bars.. I'd recommend you get one of those. They use them on other stuff that gets done up a lot tighter than that bung, so the power bar option. might be useful in the future.

Edited February 27, 2023 by Mech

[p5200]

I used my calipers and measured the socket it's 10mm. I've got the chain on pretty sure the cam is timed correctly. The last timing chain I put on was many years ago on my old 69 Dodge Dart Swinger lol! If I'm not mistaken, if it is off it has to be a tooth one direction or the other sound right? I won't get the nut I need till between Wednesday and Friday. I'll probably get my grandson to come out and double check the timing. He works with a lot of old cars and trucks restoring them. His eyes are better than mine so I think I'd better play it safe.

[Mech]

We can move the sprocket in increments of a quarter of a tooth.. It shouldn't be more than one quarter of a tooth out. Hopefully less.

Edited February 27, 2023 by Mech

[Gwbarm]

Top dead center on the compression stroke both cam lobes should be pointed down, there is a line on the cam gear that should be level with the top of the head.

[p5200]

I followed the directions in the service manual. The cam has a line on the left and right side which are supposed to line up with the top of the head. With the T mark on the flywheel lined up with the indicator in the timing hole, both cam lines are within an eighth of an inch of being perfect with the head so I believe, the timing should be right. My grandson is supposed to come by tomorrow after work and check it since he has much better eyes.

[Mech]

If your links are a half inch long each then it will be right. If they are shorter you may get it slightly better..  Another consideration is that the chain is going to stretch a bit in the first short time and allow the cam to retard itself slightly.. If those 1/8ths are retarded you might be better to adjust it a half link so it's a little advanced. If you got it to 3/16 advanced it would move back the 1/16 pretty soon and then be in a good place for the subsequent stretching of the chain as the slippers wear and the chain stretches with use.

We can always get them within a quarter of a link one side of the mark or the other, but it's sometimes best to set them up a little beyond that if we know the initial stretch is going to work in our favour and bring it closer than a quarter link. If the options are getting it a little advanced or a little retarded, it's better generally to choose the advanced option, anticipating the stretch will bring it within a quarter of a link of perfect soon.

Remember we can adjust the cam timing by a half a link at a time, and choose the best option for that new chain accordingly. If we are fitting a used chain that isn't going to have any initial stretch then we factor that in.

[p5200]

Well, it all sounds good but I wouldn't know where to begin to get it any better.

[Mech]

From another thread..  Your G/son might like to read it.  People that have a half link out timing have huge trouble understanding how to move it a half link,  so I wrote this a while ago... 

To do as I suggest and move the cam by a half link, you don't need to drop the chain off the crank.

For the sake of an example we will say that with the crank timing marks lined up, the cam timing marks are a half tooth to the right(clockwise), and that the cam timing marks on the bike we are working on are straight up and down. If the timing marks are flat across then you could put a mark straight up and down.

All you need to do is hold the chain at the top, in line with the mark on the cam sprocket, you will be holding a link that's slightly to the right of the very top, then pull the sprocket away from the cam and drop it down and work the chain off the sprocket without letting go of the link. Now turn the crank till the chain has moved one link through your fingers. In this example the crank would need rotating to the right(clockwise). Now slip the cam sprocket up or back in and fit the timing mark(or the mark you'd made), back into the link between your fingers. Put the sprocket on the cam.

Now you have the cam timing mark, the mark that used to be a half link to the right, back right where it used to be, looking a half link to the right.. But.. when you turn the crank the one link's worth of rotation it needs to get it's marks lined up again, (to the left/anti-clockwise), the cam is going to move half the distance, which is half a link. Both marks line up. Turn the cam till the bolt holes line up and put the bolts in.

 

Just know it can be moved by a half link P5200, and plan accordingly. Aim to get the marks slightly advanced for a new chain.

 

[Mech]

Oh..  The last thing I should mention..  I promise..

Sometimes to get it where we need it, we have to move a half link forwards(by moving one crank link), and then a whole link backwards(by moving the chain one link on the cam).

 

Edited February 28, 2023 by Mech