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4Strokes
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Panterra 49/72cc Timing Marks

Post by 4Strokes » Tue May 24, 2016 6:57 am

Topic: Where timing marks on the Panterra 49/72cc?
Author: panterra 50
Posted: 07/29/2006 3:44:49 PM

what part of the engine is the timing at, and is it a sprocket?

Reply by superhondaz50 on 07/29/2006 5:31:03 PM
get a crf70 manual, it will tell you everything you need and then some

Reply by panterra 50 on 07/29/2006 6:04:09 PM
and then some what?

Reply by Smokin101 on 07/29/2006 6:44:37 PM
It will tell you everything you need to know, and everything you don't need to know. You may not want to mess with the timing, if you have never taken it apart, it's probably fine. But get you a manual and you won't need these forums for much except where to find certain parts. The timing is controlled by 2 sprokets, one on the crankshaft, and one on the camshaft, connected by a chain, of course. Here's a crash course on 4 stroke theory, 1st- intake stroke-intake valve opens, the piston travels down and fuel/air is pulled in. 2nd- compression stroke-intake valve closes, piston travels up and the fuel air is compressed. 3rd- Power stroke- when the piston hits the top of the 2nd stroke the spark plug sparks, fuel/air is ignited, and the piston is forced down, 4th-exhaust stroke- exhaust valve opens, the piston travels up and the exhaust is released. Now the whole process starts again. Valve gaps play an important role in the engine timing, if the valve doesn't open when it should, or opens too soon the entire 4 stroke process is screwed. If the gap is too small or too big the valve's don't open and close when they should, making it seem the timing is off. I.E. if you ever heard it backfire, then the exhaust valve gap is too small, if it seems to easy to kick start (say it doesn't push back on the compression stroke as it should) then one of the valve's has opened too soon. Anyways I would tell you more but you're probably tired of reading this and scratching your head wondering what the heck I'm talking about. If you want to check your gaps get a feeler guage, a metric one, put the engine on the compression stroke and wiggle the lifters, if they don't move at all then they need to be regapped. Pull out the 0.05 feeler guage, if its metric, loosen the valve nuts, and place the guage between the valve stem and the lifter, tighten the nut finger tight making sure it doesn't get so tight you can't remove the guage, tighten the nut with a 9mm six point socket, again check to make sure you can still remove the guage. Anyways that's how you check and maintain valve gaps, I'm sure nobody cares, and someone will probably contradict what I have said. But if you haven't changed the timing then you won't have to mess with the timing, it can't just change unless a tooth has broken on the timing sprockets, or the chain has somehow managed to come off the timing sprocets, oh and the timing chain can stretch too. If you have taken it apart and didn't mark the timing on the sproket and timing chain, your best bet is to get someone else to do it for you. Anyways I hope this will help explain some things for you, and maybe you can use this advice to start doing it on your own. There's not too much more you need to know to rebuild and maintain the bike.

Reply by Smokin101 on 07/29/2006 6:48:10 PM
Wow....didn't realize it was sooo looooong. Sorry Well maybe someone can use the knowledge I learned in power and mechanics. It applies to all 4 stroke motors, from lawn mowers to high performance sports cars, except the mazda rotory motors.

Reply by panterra 50 on 07/29/2006 11:07:31 PM
lol its ok i need all the info i can get so is it just easyest just to mark the sproket and the chain so they line up?

Reply by panterra 50 on 07/30/2006 11:16:29 AM
should it be a Service Manual or a Owners Manual for the crf 70

Reply by superhondaz50 on 07/30/2006 12:04:25 PM
service manual. thanks smokin101 for typing all that, my fingers hurt just looking at it.

Reply by panterra 50 on 07/30/2006 12:25:32 PM
lol thanks

Reply by Smokin101 on 07/30/2006 2:14:50 PM
LOL, no problem. Yeah if you're going to check the timing or do a rebuild, look for the dot on the timing sprocket in the head of the motor and mark that on the chain too, that way you don't put the chain on wrong. Plus don't let the chain move or get pushed off the sprocket inside on the crankshaft. Don't turn the motor when the chain is off either. As long as the chain stays in place on the crankshaft, and you have marked the chain to line up with the sprocket mark, it should be easy. There's also a 'T' with a line on the uhhh flywheel, I think that's what it's called. Line that 'T' up with the groove on the case, and the timing sprocket mark should point straight to the front of the bike, and that's how you set time and valve gaps. The motor has to be on the compression stroke for it to be set properly. You can tell it's on the compression stroke by looking at the lifters in the head, and making sure neither lifter moves when turning the flywheel. OH and there's and arrow on the flywheel that tells you which way to turn it. Hope this helps. I know it's a lot to take in but after you read all this and then see how it works you should be able to figure it out. If needed I could rewrite this in order for rebuilding, valve gaps and timing and send it to you in a email or something. Or maybe I'll just make a topic with everything written in order.

Reply by Smokin101 on 07/30/2006 2:18:42 PM
Also, many bikes have extra sprockets on the timing chain inside the crankcase preventing timing chain slack and keeps the chain from coming off the crankshaft. I don't know if the Panterra's have them, I haven't tore one apart that far, but taking every precaution to prevent it is the best practice.

Reply by panterra 50 on 07/30/2006 3:58:02 PM
well i see what u are talking about i see the dote on the sproket but there is two peaces of metol stiking out the dote is right in between them and where. the T is on the flywheel there is a small notch where the T line up and so dose the little dote on the sproket.

Reply by Smokin101 on 07/30/2006 5:28:56 PM
Well I just went and tore my bike down some, just to make sure I got everything right, which I did. The 2 pieces of metal, are they on the sprocket or the head? I have 2 pieces of metal that hold the timing cap in place so it doesn't move when you tighten the bolt. The sprocket dot should be pointing straight to the front of the bike, when the flywheel 'T' mark is lined up with the groove. (actually there is a line next to the 'T', that is the one to line up) The 'F' on there just shows when the spark plug fires. Anyway if those two notches are lined up where they should be, then you can take the head off, not the whole thing just the cover, 4 nuts hold it on there. Now you can check valve gaps, the lifters you will see, should wiggle a little, just a little. If they are tight or really loose, then they need adjusting. I guess that's what you are trying to do. If you are adjusting timing, unless it's been taken apart before, the timing should be fine. I guess it's a good thing I just checked mine out, the intake valve had no gap, but yet it still runs fine. This should all be correct, unless Panterra used different sprockets for the bike. Mine has a ZC on the timing sprocket. If you remove the timing sprocket also make sure to mark a groove on the camshaft, that shows where the dot on the sprocket should be. That way you never put the sprocket on wrong. If your timing marks don't line up as I described, then someone may well have put the sprocket on wrong, either at the factory, or if your bike was used someone else did it and didn't do what they were supposed to, which makes things slightly more difficult.

Reply by Smokin101 on 07/30/2006 5:32:12 PM
I almost wish you could just send it to me, I would fix it for free. It's my hobby, I love working with motors.

Reply by panterra 50 on 07/30/2006 5:44:02 PM
i think i get u now when the dot is facing the front of the bike you mark it. but do u like draw a line from the dot to the chain.

Reply by Smokin101 on 07/30/2006 6:00:41 PM
Yeah that will work fine, it doesn't have to be all lined up when you mark it, just as long as it is marked before it is taken apart. Mark the line from the dot, to the chain and the camshaft, that way when you take it apart everything will go back exactly the way it came off. Here's a little forshadowing, the timing sprocket will be a little agravating to put back on the camshaft, mostly because of the tension on the timing chain, don't force it, get it as close to going on there as you can and put the bolts in and slowly tighten them until the sprocket pops back on the camshaft. Hope everything goes well for you, if you have anymore problems you know where to find me. Good Luck.

Reply by panterra 50 on 07/30/2006 6:03:06 PM
thanks alot.

Reply by panterra 50 on 07/30/2006 6:25:44 PM
ok well i got the 3 skrews off the sproket and it came loose but the top head will not come off?

Reply by Smokin101 on 07/30/2006 6:44:11 PM
Just the top to the head not the whole thing right? If that's the case then the gasket is sticking and you need to be very careful when removing it, otherwise it will tear and you will need a new one. Use a flathead screwdriver to gently pry it away from the head. If you're removing the whole head, there is a bolt on the side holding it to the cylinder. Same goes for removing the cylinder, there's a bolt on the side of it too. The exhaust pipe also has to be taken off, when taking that much apart.

Reply by Smokin101 on 07/30/2006 6:46:23 PM
Same applies to the other gaskets, that you will run into. Be very careful, you can still use them if they are in good condition.

Reply by panterra 50 on 07/30/2006 6:49:44 PM
never minde i got it off both top head and cilender but the gaskets are in bad condishion the problem i ran in to is i dont no how to take the piston off oh ya it is scared big time from the sides.

Reply by Smokin101 on 07/30/2006 7:20:17 PM
Use a pair of needle nose pliers and a small flathead screwdriver, you have to take out the retaining pin, there are to c clips holding it in there. You only have to take out one and the piston will come off. Then your done, all that is left is putting the new parts in and putting it together again.

Reply by panterra 50 on 07/30/2006 7:28:10 PM
that sounds good thanks for all your help.

Reply by Smokin101 on 07/30/2006 7:41:34 PM
Not a problem glad to help out a fellow rider.

Reply by panterra 50 on 08/02/2006 5:16:30 PM
smoking101 im getting the big bore kit tomaro and i was wondering what should the timing sproket be torked down to. and is the head torked down to 7-8 lbs.

Reply by Smokin101 on 08/03/2006 2:45:03 PM
Well I don't have a service manual, but from what Superhondaz said, you shouldn't torque anything more than 10.lbs, however there are a few bolts that require much more than that, but for what you are doing 10.lbs should be fine. I don't have a torque wrench, at least not a good one, so I don't use one. Just use a little common sense for the bolts you are tightening, make sure you don't put all your weight into it. Usually a little less than arm strength is fine. Don't put too much effort into it. I have been taking these bikes apart for a while and never once used a torque wrench, I have yet to strip a bolt or screw thread.

Reply by panterra 50 on 08/04/2006 8:08:31 PM
man what a diffrence in power way more. thanks again for all your guys help.

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