went and checked my clearances....have never seen this before!!! the clerance between the lobes and buckets towards the cam sprockets were both in spec...now the ones furthest away from the sprockets were WAY out of wack!!!! the intake was .330 mm (.013 in) and the exhaust was .483 mm (.019 in) is abnormal??? someone chime in and help a brother out!!! also checking them was not easy you kinda have to jam the gauges in there (the angles ones) until it's flat part is under then slide and see if there's resistance!! is that the right way maybe i'm just being stupid!! LOL

Thanks!

 

Did you check the service manual? The spread sounds perfectly normal to me, but ALWAYS adjust it according to factory specs. Remember exhaust valves get way hotter than intake, and always need larger clearances.

 

manual sspeecs are intake = .10 - .20 mm or .006 in. and exhaust= .20- .30 mm or .010 in

what doesnt seem right to me is the one on both cams closest to the cam sprockets are in spec the ones furthest are out of spec!!

 

Sorry, I didn't get the that the first read. Your numbers of .006" and .010" are the averages, and exactly what I'd adjust them to.

As for the cause, it's hard to know, since this is your first time, right? They're definitely way out of whack as the specs go, but definitely not worrysome in this case (I'd be if they were tight, which can burn valves); my motorcycle calls for .012 and .018, respectively. You should notice a modest increase in power when you're done, since those valves were not opening enough.

I'd adjust all valves the same (even if within specs), and go from there. You didn't mention the history of your quad. One thing is a brand new motor on its first scheduled check, and another a high mileage one, that maybe nobody did any maintenance on it. If new, you can't rule out factory error, so just adjust them all the same and watch them next time. Just for the heck of it, check the cam bearing bolts on that side to make sure they're tight.

And make sure you develop a technique where you slide the feeler gauge at the same angle, or buy feeler gauges bent at an angle; if you're 'attacking' the gap at an angle, you'll get a wrong reading. Also 'define' your own optimal feel, and stick with it. I like enough drag to make sure there's no extra clearance (oil makes it feel looser than it really is), but not so much that I have to force the gauge in. Hard to explain in words, but just try to make sure the feeler's gauge number is what you have in gap, and be consistent.

Keep us posted.

 

my motor was a fresh rebuild top end from nicholas cycle was his stage 3 before he turned that into his 574 mine is a 558 ...he adjusted my valves last and the only thing i've been able to think of is he did have the timing chain on when he did he adjustments which would give more clearance!!!..right? al he had was my cams, head, and cam cover and cylinder at that time asked him if he wanted the whole engine back ...he said would not be necessary


also i used angle gauges but the way you have to get them in is force them down until the flat part is under then check for clearance then i went a size bigger and smaller to check my readings. does that sound right??!!


there was also 2 months ride time on the quad 1 drag race and 1 weekend of racing....do you really think i should gain more power??? it did feel kinda sluggish!!

 

well i talked to Doug and he said that it sounds like my valves are bent!! so now the head comes off!!!! i don't think they're bent though cause it ran strong before all this !!! wouldn't the quad run real sh*tty if they were bent? cause if they got bent they've been bent since it first put it back together!!! and i took 5th or 6th place at the last 2 drag races i was in....how much power would bent valves rob me of??

MAN!!!!!! this is really pissing me off!!!!!!!!!!!!!!!!!!
[img]i/expressions/face-icon-small-mad.gif[/img]

 

i just got to thinking...how can 2 valves from to different sides be bent and not the other 2 (one is an intake valve out of clearance and the other is an exhaust valve both from the shifter side of engine away from timing chain!!!)??? doesnt make any sense!!! [img]i/expressions/face-icon-small-confused.gif[/img]

 

Man, this got a lot more complicated than my limited experience. Only thing I'll mention is both a rebuild job and racing can screw things up, or a combination, so keep that in mind. Furthermore, a rebuild problem could be either the parts or the labor (or again, both).
I'd definitely take the head down pronto; much cheaper now than after a catastrophic failure at 6K rpms. As for the cost, that'll be complicated. I'd try to make a deal with the shop that did the rebuild, where an independent mechanic approved by both sides does the tear down, and his findings are binding: whoever is at fault foots the bill (might be a combination), but the shop might only take the blame for labor problems, not parts. Deal with that issue in advance too.
Good luck man. Wish I could be of more help. Maybe somebody else, or find a board more technically oriented. I'm looking for one too to learn about the SP800. Give me a shout if you do.
JC

 

thanks for the help youu gave!!

 

I wouldn't take it apart until I knew for sure you had leaking valves, If you don't own a compression tester it's time to buy one. You can test the cylinder pressure and quickly know when there's an internal problem with out guessing. Try to get one that the gauge can be unscrewed from the hose assy that way you can add a fitting to the hose that allows you to connect it to an air compressor. You can pressurize the cylinder (remove the schraeder valve from the hose fitting that screws into the head) with the piston at tdc on the compression stroke (valves all closed) and then check for air leaks at the exhaust port and the intake port. This will tell you if there is valve leakage, there should not be any airflow in either port out of the cylinder. Some air will leak by the rings and exit through the crankcase breather which is normal unless it's a large amount. If the valves pass this test get the shims you need to set the valve clearence to spec.