I have bought my Royal Enfield 350 Classic bike 3 month back. Frequently I am hearing heavy metal crashing/friction sound when I start the bike. Sound is bit annoying. I am not even able to explain this problem in service centres, since it can not be regenerated. It happens randomly. I also suspect there is something wrong with engine. Has anyone faced this problem?
I have the same problem with my classic 350. It is due to starter sprag bearing wear out. Replace it and it will be solved
My best bet would be you have a broken sprag clutch. Have it checked and let us know. :)
It could be a few things, from valve gear noise to piston slap to gearbox rattle, etc. Either way, you should get someone who knows engines to check it out for you, to either repair it or at least check that further damage is not being done.
For a new bike, below 10K trip, Sprag clutch should not be at fault. However you may confirm it your self by removing the Left Hand Side engine casing. Relax its easy. You will need an 8mm T for casing and other sizes to remove foot paddle. A hell lot of oil will drain, so you may incline the bike to the opposite side, fully. A lot of debris inside the casing will tell you what the issue is. You remove the Sprag clutch bearing (one way bearing) and use Kickstart old school type. If the self assembly isn't too much worn out, the insude bearing will cost 2K original and 300 aftermarket. Complete assembly 4700 original and 2K to 3K aftermarket.