[Tommy CRF250R]

Hi I have just swapped my CRF450 for a CRF250R and there is a slight chapping noise coming from the engine. The boy I swapped said the timing chain is slipping now and then which is causing this. But he said it’s fine and will only cost £80 to fix. Is this correct? He said it’s fine to ride. I took it a small run and it’s pulling fine but I’m concerned and don’t want to ride it if it can cause more damage. Thanks

[JimDirt]

Welcome to the site !!

That is what it sounds like from your description , timing chains are normal wear and tear items , and part of general maintenance , if it is noisy then i would look into either changing it , or having someone change it (either way it needs to be done , sooner than later)

As for the cost , it must be including Labor , as that is about double of what the chain itself should cost

[Tommy CRF250R]

Hi Jim it’s good to find this site. Thanks.
Yeah I’m hoping that’s all it is. Do you know if with the timing chain skipping can that do more damage to other internal engine parts? As I’m a car if timings out it will destroy the engine. Thanks for your quick reply bud

[JimDirt]

The timing being off can cause the valve to hit the piston due to the tight tolerances , especially at high RPM's , this can cause a flat spot on the rod bearing eventually causing a rod knock/crank failure as well as piston damage and valve and possible head damage , if you suspect the timing is off , it is best not to run it till you replace the chain and confirm the timing is correct

One other item to check over closely is the Timing Chain Tensioner , they do break from time to time and can cause issues with not only the chain becoming loose and skipping , but parts can break off and get into the flywheel area and get ground up and distribute thru the engine causing serious damage including destroying crank bearings , so check the function and physical looks of the tensioner when you remove it , make sure the detents work and that the unit is intact

I would also recommend getting yourself a Factory Honda Service Manual , the information will give you all the tolerances and torque specs as well as disassembly and assembly procedures as well as informative pictures to identify parts and where/how they fit and a list of any special tools needed such as Flywheel Pullers , etc.

(Just click on drop down menu to find your bike)
https://www.crfsonly.com/catalog/produc ... ts_id/3226

[Tommy CRF250R]

Hi Jim sorry for the late reply. That’s great thanks for your info. Appreciated bud

[JimDirt]

No problem , glad to help