Yes, a leakdown test says explicitly what is leaking. You charge the cylinder with compressed air hooked to a dual gauge, one reads the input pressure, and the other reads the actual cylinder pressure. From there you get a leakdown %. Depending on what you are doing, there are acceptable pressures (racing, street, etc.). The leaking air then escapes from wherever the seal is bad - crankcase for rings, intake for intake valves, exhaust for exhaust valves. In a production motor, there is the gap the factory aims for, then there is the gap that the machine actually produces. Without matching a ring to a cylinder and gapping by hand, there is really no way to make an accurate determination of what has happened. WITHOUT a leakdown tester, I suppose measuring for excess gap would really be the only way to check the seal (but at that point, there is no reason to check - install new ring). I'd just rather pay a shop the 50 dollars it would probably cost to do a leakdown I used to work at an engine shop, and have gapped probably hundreds of rings, so I'm somewhat familiar with the causes of possible variation. Was just curious if I could learn something new from experience
As my filter has gotten increasingly dirty it can't pass air through the small patch behind the snorkel and you can see dirt collecting across the entire filter media. I do like that air port thing though, that's cool.
47:04 hours and 1,843 miles here, but I've only had my bike for 5 days. At that rate I'll have 134,539 miles after one year. haha! that ain't gonna happen. _
Pretty slick...and I thought screw and locknut XR's were easy. No having to look thru a hole to see a "T" on the flywheel that wants to rotate past the notch every time... 450 miles, oil/filter change w/ Silkolene Pro 4 SX 15w-50 Left In. 0.006" no 0.005" yes, medium 0.004" yes, loose Right In. 0.005" no 0.004" yes, medium Left Exh. 0.006" yes, loose 0.007" yes, tight Right Exh. 0.006" yes, medium 0.007" no
Ha...I've become worthless with inches in thousanths. I can understand .10-.15 and .15-.20 millimeters. They are telling us once you get them dialed in the first time they should be good for thousands of miles.
I wrote it down in inches just because that's the larger number on my gauges....the mm is a smaller font The motor is pretty low miles and hasn't really been taxed much yet....once I get a few good days of aggressive offroad under it's belt I'll do it again. I did want to get a gut check a few miles into things before I put the Safari tank on - once I get that on I won't be as anxious to look under the hood again for a while.
I don't understand this thread. Can someone help me out? Why are the valves loosening? This is completely counter-intuitive. The clearances should be getting tighter as the valves and seats wear against each other and the valves settle farther into the seat. What's going on?
Try cyclebuy.com in Oregon, justgastanks.com, or Bill's Husky - the sponsor here. I thought he had a small discount on them. I don't think there's any great markup on them comming from NZ/AUS.
I did the first adjustment on mine today at 900 miles. Left ex was at .23. All others were in spec. It was pretty easy but reminded me why I like two strokes.
Since the shims only come in .05mm increments I suspect they set them up at the loose end of the range for breakin and that's why the first check is at 1000km. Get everything dialed at the first service. This is a pretty sharp group of DIY'rs but I'll bet the majority drop their bike off to their dealer and that's what the factory expects.
We're talking very small amounts of difference in clearance - I don't think you'll see any wear in this new a motor, but more likely things bedding in after some heat cycles are put in a new motor. Lots of different parts in a valvetrain, and they get assembled and not much changes until they do some work and everything seats into it's new home.
Just wanted to chime in w/ my findings as well. Did this over the weekend w/ a local fella I met on ADV- great guy w/ all the right tools (not that it takes anything fancy, but good tools make for good/easier work.) My 630 is now at 1,150 miles, and the short version is that all were in spec.: Exhaust: Left @ .18, right @ .17 Intake: Left @ .13, right @ .10 How long should I go before I check them again? Interested in hearing your opinions/insights on this. Also- this is the second time I've removed the tank, and for the life of me I can't figure out how to (easily) disconnect the fuel line from the fuel pump (did it once, but pressing down on that black ring, as the manual states, didn't easily do it.) It is easy at the other end of that line, where it connects to the EFI. That one seems the no-brainer as it's easy to get to and has clear pinch buttons on sides of the connector that makes popping it off and on a breeze. Oh yeah- that thermostat is in an annoying spot. It's certainly possible to wiggle the valve cover out and back in, but annoying. I dismounted the radiators to gain a few more mm's of wiggle room. Thanks- Eric
I rode 6000 miles on my TE630 before my valves required any shims. I do hope it settles down. I wonder what parts you have to look into replacing once you are no longer able to shim them.
Sounds like you got it dialed Eric. Although the right intake seems tight. Fortunately they loosen up as the motor gets hot. How do you determine the exact clearance? I use a 'go, no-go' with graduating feelers, but my feelers graduate by at least a couple of tenths of millimeters. So as long as I get a .17 go and a .20 no-go for exhaust I know I'm in spec. Same for intake, .12 go, .15 no go. My gauges don't have .13 and .14mm. Maybe I need new feeler gauges, eh?? I use the set I got for my KTM, has the same clearance specs as the Husky. I will tell you it's a helluva lot easier to change a shim on the Husky. You have to remove the entire valve train on the KTM. I guess all the previous 4-strokes are like that. The husky setup is really fantastic. I would check that right intake again in a couple of thousand miles. The other issue mentioned previously is that the shims only come in .05mm increments. So if your intake is really at .10 then putting the next smaller shim in there could put you at or over .15 and then it would be loose. One of my intakes was loose and adding the next size shim tightened it up to spec and eliminated the tick I could hear when the motor got hot. Obviously it's better for them to run a little loose than too tight or burnt valves could be the result since they can't close all the way on compression, and loss of power of course. I managed to get my valve cover off by removing all of the radiator fastenings give it enough 'give' to move out of the way. I had the exact same issues with the fuel line, but was able to work the connection at the pump much easier once the tank was off. Frankly I think it makes no difference which one comes off to remove the tank. Mine dribbled fuel on an almost empty tank. I'm not sure it wouldn't leak a bunch on a full tank. Then again, maybe it was just residual fuel in the line. My understanding is the pump doesn't leak fuel, it pumps it. Seems to be that way on my Kawasaki Versys, also fuel injected, pump in the tank.
Thanks for the feedback and detailed response. I was using the set this fella had brought over with him, and they went to what I guess are (for lack of better phrasing) 100th's of a mm. So, for example, on the one that I listed as .17 the .1728 leaf was just a tad snug (if that...more like some clear resistance) but the next one down from that leaf was too loose- so we called it .17. Agreed on the tank- I can't see what diff it makes as to which end of the fuel line you disconnect...for me the lower end at the EFI was easiest. Mine also dribbled on a close to empty tank...I'd swear more dribble than the last time I removed it w/ a full tank. Either way I am sure it's just what was in the line- the tank holds tight once clear of the bike. This bike is a pleasure to tinker with, that's for sure. Now that I mention that let me ask one more Q... While we were at it we hit the grease nipples w/ a grease gun- the lower susp linkage. Of course they were fine, but it got us to looking for a nipple to the swingarm pivot...didn't see one. Does the 630 have a nipple on the swingarm pivot? Like most I am always on the lookout for handy and easily accessible nipples...excepting my own, of course. Thanks! Eric
I ended up loosening the radiators for wiggle room, and loosened the clamp on the upper coolant hose near the valve cover and drained a few ounces into a cup, then pushed the hose aside. I have a few sets of feeler gauges, but the ones that were handy (on top of the workbench) were the set I used on my 525, with pre-bent tips on the two gauges I needed - bonus! Never thought I'd find myself saying I don't miss the screw & locknut days
and/or have the valve seats re-cut.. throwing in new valves without ensuring the seats match is futile.
What I really meant was a complete head rebuild, not just valves. My hope is that this motor goes a thousand or more hours before valve work is required. They are stainless valves which is a plus. Titatium don't seem to last as long.
