huuuuge valve gap??!!!

[klrdon@comcast.net]

Shim to proper gap and check again in a while. Maybe the fault is the last (original?) adjustment or factory assembly. It seems it is usually the simple stuff that is the problem with these bikes. Don M -----Original Message----- From: Jeff Saline Sent: Saturday, May 21, 2011 3:52 PM To: simoninthewoods@... Cc: DSN_KLR650@yahoogroups.com Subject: Re: [DSN_KLR650] HUUUUGE Valve Gap??!!! On Sat, 21 May 2011 17:20:41 -0000 "simoninthewoods" writes:

> Greetings fellow klristas! > I have agreed to check the valve clearances on a friend's klr as it > has been running fine but very clattery. It wasn't clear where the > rattling sound was coming from but we decided to start with checking > the valves before moving on to more esoteric possibilities. I have > got the cover off (haven't touched the camchain tensioner or cam > caps yet). > Both inlet valves are tight but still within spec; the exhaust > valves though are a different matter - left is 0.80mm and right is > 1.65mm!!! This seems massively outside spec, and yet the bike has > been running fine. My question is would the bike run with such large > exhaust valve gaps (in which case I need to replace both exhaust > shims - not a problem as I have performed this on my own klr)? Or am > I doing something wrong? The engine is at TDC as confirmed by timing > mark and all cam lobes pointing 'out'. Compression is fine and bike > runs fine. > Any thoughts?? > Many thanks > Simon

<><><><><><><> <><><><><><><> Simon, I'd try first what Fred is suggesting with turning the engine over another 360 degrees. But I don't think that will do the job for you. Those are really huge gaps and the only things I can think of that would cause that is carbon on valve faces holding the valves open or bent/sticky valves and they aren't closing all the way under slow engine rotation. I think if I was working on this bike I'd probably pull the cams and shims and buckets. Then I'd measure the height of the valves and then tap on them with a soft faced hammer. Maybe the tapping would allow the valves to close a bit more if they are sticking. If nothing changed I'd probably pull the header pipe and look in the exhaust port to see what I could learn from that. Then I imagine I'd be pulling the head to fix the valves. Valve clearances don't get larger with normal wear. As the valve face and seat wear the valve moves deeper into the head and that moves the stem closer to the cam. That's what makes the clearance get smaller. By putting in a thinner shim you adjust the clearance to manufacturers specs. I can't imagine anyone putting the engine together with the kind of clearances you've described. You must have had to use stacked feeler gauges just to get the clearances figured out. Best, Jeff Saline ABC # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads.org The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650, 79 R100RT . . ____________________________________________________________ SHOCKING: iPad 2 Only $18.55 - 95% Off U.S Based auction site giving away 1000 iPads, TV's, PS3's at 95% off Retail! http://thirdpartyoffers.juno.com/TGL3141/4dd81825c9d6ef75st01vuc ------------------------------------ List Sponsors - Dual Sport News: http://www.dualsportnews.com Arrowhead Motorsports: http://www.arrowheadmotorsports.com List FAQ courtesy of Chris Krok: http://www.bigcee.com/klr650faq.html Member Map: http://groups.yahoo.com/group/DSN_KLR650/app/peoplemap/view/map Group Apps: http://groups.yahoo.com/group/DSN_KLR650/grouplets/subscriptionsYahoo! Groups Links ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1375 / Virus Database: 1509/3651 - Release Date: 05/21/11