I bought a new xr 70 for my kids about 4 months ago.It`s done around 10hrs work.Recently an elder boy had a ride and was gone for about 2hrs.On Pre-ride mechanical inspection the next ride I noticed stretch in chain,not uncommon.2 anchor bolts rear sprocket-hub missing (what the).But that wasn`t the problem.On start up with full choke,it smokes blue.It will keep smoking until choke is turned off and about a minute after.Now,as there is no apparent loss of power and the plug does not foul,do I presume that this is a small amount of blow-by caused by the closed throat on a cold motor.As I have owned XR`s before,when I was a kid and know about how restrictive the choke on a Kiehin is,with it`s small openning and overly sprung trapdoor choke and combined with maybe a rich mixture is drawing oil till the choke is turned off and maybe do a needle clip adjust up a peg.OR and I hate to say it,is it a valve stem seal failure from the lad overstepping the new bike run in boundaries as the back sprocket,chain and tyre peel(cuts,rubber balls) give evidence to him obviously doing burnouts or wheelspins suggest.These are not cheap peices of machinary as you all well no and I want to know if it`s a pull down and repair job I want to know first before I give his dad the bill.Does anyone suffer this,or sufferred in the past with same bike.Any advice would be appreciated as I am very upset about the vandalism and lack of respect some people have towards others property.GOOD OR BAD NEWS JUST GIVE IT TO ME
