CRF's Only Forums

I have a 2011 CRF250x, I've always been on top of maintenance, never really flogged the bike. From about this time last year the bike developed a sort of rubbing/scraping noise coming from the left side of the motor only when it was 3/4 throttle or more. I thought it might have been drivetrain so I pulled over, put it in neutral and did the same thing (3/4 throttle and more) while sitting still and it did the same thing. The bike sat in the shed for about 6 months and then I took it out to see if I could figure it out. I pulled the valve cover off and everything seemed normal, nothing loose, valves still in clearances. I also pulled the cam chain tensioner out, I wasn't game enough to go further so I put it back together and started it. No noise. It was fine, I rode it for about 1-2 months with no noise at all. I had to get a friend to ride it to get it inspected for road worthy and the noise is back. I've tried taking the cam chain tensioner out again and it hasn't worked this time. The noise has also become worse and at lower RPM (more like 2/3 throttle now). I'm wondering if this has been experienced by anyone else also and how they fixed it. I'm not game enough to continue riding it as I'm not sure whether the noise is something going bad. I'm keen to fix the problem as I've been without a bike for so long, I just don't have the money to pay someone to dig around the bike for me. Thanks in advance

It sounds like the timing chain has stretched a little as well as the tensioner may be sticking , so i would guess you will need to replace the timing chain and tensioner , while you're in there , look at the chain guides , you will need a flywheel puller to change the chain

It sounds like the timing chain has stretched a little as well as the tensioner may be sticking , so i would guess you will need to replace the timing chain and tensioner , while you're in there , look at the chain guides , you will need a flywheel puller to change the chain

Thank you, that is what I was thinking also. If the tensioner is sticking does that mean that it needs replacing or is there a way to stop it from sticking? I'm starting work on it tonight and am keen to get it fixed as soon as I can. Is there a way to remove the flywheel without a flywheel puller?

It sounds like the timing chain has stretched a little as well as the tensioner may be sticking , so i would guess you will need to replace the timing chain and tensioner , while you're in there , look at the chain guides , you will need a flywheel puller to change the chain

Thank you, that is what I was thinking also. If the tensioner is sticking does that mean that it needs replacing or is there a way to stop it from sticking? I'm starting work on it tonight and am keen to get it fixed as soon as I can. Is there a way to remove the flywheel without a flywheel puller?

Usually , the Tensioner will work , or it locks and breaks apart , basically exploding , but sometimes it gets gummy inside and can stick or the spring gets weak , personally i would replace it to eliminate it from the symptoms , some people use the manual ones , but i prefer the OEM one .....as far as the flywheel puller goes , NO , you can't get it off without the "correct" puller for your bike , and care has to be taken when using it , as the end of the crank has a brass oiling guide , if that gets damaged in any way , by not using the correct puller , or by using the puller incorrectly , it can stop oil flow thru the engine and you will have to replace the entire crank along with anything else in the engine that loses oil flow to it , so make sure you get a puller made for your bike (Ken sells them here)

Manual Tensioner:
*cheaper*
https://www.crfsonly.com/catalog/produc ... ts_id/5836
*expensive*
https://www.crfsonly.com/catalog/produc ... ts_id/2052


Flywheel Puller:
https://www.crfsonly.com/catalog/produc ... cts_id/624

It sounds like the timing chain has stretched a little as well as the tensioner may be sticking , so i would guess you will need to replace the timing chain and tensioner , while you're in there , look at the chain guides , you will need a flywheel puller to change the chain

Thank you, that is what I was thinking also. If the tensioner is sticking does that mean that it needs replacing or is there a way to stop it from sticking? I'm starting work on it tonight and am keen to get it fixed as soon as I can. Is there a way to remove the flywheel without a flywheel puller?

Usually , the Tensioner will work , or it locks and breaks apart , basically exploding , but sometimes it gets gummy inside and can stick or the spring gets weak , personally i would replace it to eliminate it from the symptoms , some people use the manual ones , but i prefer the OEM one .....as far as the flywheel puller goes , NO , you can't get it off without the "correct" puller for your bike , and care has to be taken when using it , as the end of the crank has a brass oiling guide , if that gets damaged in any way , by not using the correct puller , or by using the puller incorrectly , it can stop oil flow thru the engine and you will have to replace the entire crank along with anything else in the engine that loses oil flow to it , so make sure you get a puller made for your bike (Ken sells them here)

Manual Tensioner:
*cheaper*
https://www.crfsonly.com/catalog/produc ... ts_id/5836
*expensive*
https://www.crfsonly.com/catalog/produc ... ts_id/2052


Flywheel Puller:
https://www.crfsonly.com/catalog/produc ... cts_id/624

I'm sorry for the late reply, I've had exams. If i was to replace the tensioner and it doesn't work is there any other diagnosis tricks you would use before tearing the engine apart? I'm not too confident to pull it apart and don't really want to mess it up. is there any good diagrams or videos online that you could recommend that show the steps to this process?

The only "test" , would be to try to adjust the tensioner , looking at the tensioner it has a bolt in the center of it , remove that and there is a slot down inside , you will need a small flat screwdriver that will fit down in the hole , you can turn (no more than 1/4 turn either way) the screw while the engine is running and see if the sound gets worse or goes away , this will confirm if it is the tensioner and/or the timing chain , i would also recommend buying a Factory Honda Service Manual , it will give you ALL the info you need to correctly and accurately tear apart and re-assemble the engine components along with pictures and detailed specs , its about $60 but worth every penny if you are going to work on your own bike , it will also list any specialty tools you need to do each repair (the tools i had shown in my prior post , like the flywheel puller)

Just use the drop down menu to locate your year/model bike and get it , if you're not confident on working on it , then do not try without that manual
https://www.crfsonly.com/catalog/produc ... ts_id/3226