XR250 proper valve clearance specs?

[crispy]

hey al so I've recently rebuilt an 89 xr20, I've had to get a replacement cylinder head for it due to the original being uneconomical to repair (smashed valve guides, cracked head in the usual place close to spark plug threads and 3 bent valves. I've used a 96 onwards cylinder head with earlier 89-96 valves, had valve guides reamed out to suit these valves. So i'm a little confused as to what valve clearance I use. the early model .02in inlet and .03 exhaust spec or the later .04 inch inlet and .05inch exhaust. Also it is hard to start but have had running eventually ( on sunday after 40 odd kicks). Was quiet in the valve department. I have just reset the float height tonight and will clean the carb out tomorrow and retry tomorrow night to see if it'll be any easier to start

[puddytat]

If you don't get a reply here then try the XR thread on ThumperTalk again.

[tri boy]

4 and 6thou is what I would set it to.
Tight clearances are disasterous on XR heads, (followers, cam etc)
Ol Hondas love fresh oil often.
Doesn't have to be super duper fully syn.
Semi syn is fine, but because they hold only a puddle of it, change every 3000kms or sooner. MHO

[crispy]

the reason I ask is I finally got it running on sunday after umpteen hundred kicks (or felt like it). I had adjusted the valves but here's the thing. I adjusted it as the workshop manual said and finally got it started. When it was running when I gave it a bit of a rev from idle up to half throttle it had a flat spot then picked up in the revs. I'm almost thinking maybe there's something up ignition wise here. Checked spark on my spark tester and the harder you kick it over the stronger the spark. is this one of a number of issues i'm possibly having?? Have checked carb out of the bike with fuel hose turned on checking the fuel doesn't come out the overflow tube. (haven't checked the fuel height with plastic tubing)Can't bump start at the moment as the back wheel is off while I replace the bearings and clean everything

[crispy]

Quick update, I was thinking the valve clearances aren't within spec (which I tried 3 times and couldn't fault them). Turns out it's a combination of both operator error and the fuel tap is faulty. Fuel tap only flows decently on reserve. As for my starting method that went out the window and after googling it read that someone's advice is fuel on , choke on, turn idle up wait 30 seconds then 1 slow kick to get past tdc, then 1 decent kick and should fire. Did this last night and started on first kick.

[puddytat]

Yeah...similar to the 4hundy. With that its tip over to the right so a bit of fuel comes out the carb overflow, turn up the idle a lot, decomp lever in & several slow kicks, decomp off, full choke, no throttle, past TDC,full length kick & hey presto.
That's the cold start procedure.....I'd be fucked though if I needed to get a quick getaway
When its warm, its one kick..