long distance advice

[Lloyd F. Rauschkolb]

Adjusting KLR valves is probably easy for those that are mechanically inclined I guess, but some of us struggle with it and then wonder if we did it right when we get through. (Don't suggest taking the bike to a dealer, that is just not an option any more). Believe me I would rather do that, but I don't believe for a second that dealers actually adjust the valves, and even if they do, I doubt they do a half ass job of it. I have done it myself a few times, but I just don't like to do it and I always end up wondering if I did it right. Can anybody explain why it is necessary that valves need to be checked/adjusted so often on most motorcycles and never have to be checked/adjusted on most cars? Seems like this aggravating procedure could easily be eliminated for motorcycles like it has been for cars. Lloyd Rauschkolb Gulfport, Ms.

[Fred Hink]

Most cars use hydraulic lifter that acts as the valve clearance adjuster. These rarely go bad but they do sometimes. I believe there were a few bikes (Goldwings maybe) that had hydraulic lifters for a while but now I can't think of any bikes that use them. Mechanical lifters or valve adjusters need to be adjusted because it is a fixed valve clearance and since most mechanical things wear, the only way to get your valve clearance correct is to have them adjusted. You should feel lucky for the valve clearance inspection interval on your KLR and on most double overhead cam motors need much fewer inspections/adjustment than a single overhead engine with rocker arms. I believe the trade off for a hydraulic lifter is reduced performance at higher rpms. This isn't good on a smaller engine since they usually run higher speeds to make their max HP. Fred http://www.arrowheadmotorsports.com http://www.angelfire.com/ut/moab/cmc.html

----- Original Message ----- From: "Lloyd F. Rauschkolb" To: DSN_KLR650@yahoogroups.com> Sent: Monday, January 10, 2005 4:48 PM Subject: [DSN_KLR650] KLR Valves Observation and Question > > > Adjusting KLR valves is probably easy for those that are mechanically > inclined I guess, but some of us struggle with it and then wonder if > we did it right when we get through. (Don't suggest taking the bike > to a dealer, that is just not an option any more). > > Believe me I would rather do that, but I don't believe for a second > that dealers actually adjust the valves, and even if they do, I doubt > they do a half ass job of it. I have done it myself a few times, but > I just don't like to do it and I always end up wondering if I did it > right. > > Can anybody explain why it is necessary that valves need to be > checked/adjusted so often on most motorcycles and never have to be > checked/adjusted on most cars? > > Seems like this aggravating procedure could easily be eliminated for > motorcycles like it has been for cars. > > Lloyd Rauschkolb > Gulfport, Ms.

[Guy B. Young II]

LLoyd, I'll try and explain this to you as best as I can, altho' you'll probably get a flood of responses. First, all autos and motorcycles (excluding Ducati) have valve springs. The purpose of these springs is to slam the valve closed during compression and ignition. This essentially seals off the cylinder so compression and ignition can take place without the loss of the expanding gasses that force the piston down, be converted from a linear motion to a rotatry motion by the crank. To open these valves at the proper time, you need a cam. You've had yours open so you know what these look like. The cams in the KLR operate the cams by direct contact of the cam lobe(s) to the top of the valves through the shims and the buckets they rest in. In this type of arrangement there is no latitude of error with the valve clearance. This adjustment is determined by the thickness of the shim. A things wear over time, this clearance changes. The repeated slamming of the valve against its seat can wear the valve and it's seat allowing it to effectively sink further into the head. When this occurs, the clearance between the end of the valve (throught the bucket that sits on top of the valve & spring, and the shim) close, and the valve clearance between the shim and the cam closes up (gets tighter). To correct this, you will need to replace the shim with a thinner one. BUT, the cam lobe, the top of the valve, and the shim are also wearing - having the tendancy to open the clearance between the top of the shim and the cam. Which one wins in the wear department? A good question and one that can't always be pre-determined. The manuf., however, has a pretty good idea when they engineered the engines and they came up with a conservative number. This is the mileage number they give you in the manuals as far as valve adjustment interval. This, however, should be used as a guide only. If you are a red-line kinda rider, its probably best to check them more often. Constant high speed operation and the resultant slamming of the valves has a tendancy to cause them to sink into the head faster, which closes up the clearance as described above. Suffice to say, the above decribes a purely mechanical valve actuation mechanism. There are variations, of course, where the cam activates a rocker arm, which in turn actuates the valves. In these schemes, the adjustment is made through a shim on top of the bucket the rocker hits, a shim under the bucket, or a screw and nut adjuster typically on on the end of the rocker. All of these mechanical schemes allow for no compensation in wear. If something does wear, the resultant valve clearance is going to change in one direction or the other; either tighten, or loosen up. Most autos today, and some bikes, have what's called hydraulic lifters (HL). These are basically a cylinder that has one end closed off, and this end rides on the cam and follows the cam lobe. Inside this cylinder is a piston that is captured on the other end by a clip (or swaged end). There is usally a spring inside that will keep this piston pushed up against that clip. Push on the piston, and it will sink into the bore of the cylinder as far as the spring will allow or runs out of travel. Now, add a fluid, such as motor oil, into the cylinder. Since liquids don't compress, you won't be able to push the piston down; it might as well be a solid piece. Now, add a port in the side that will allow engine oil to enter, or escape, and this changes the ball game. If this hydraulic was used to ride on a cam, that then pushed on a valve (through a rocker arm) and there was no port, you essentially have a mechanical system as described earlier. The hydraulic lifter might as well be a solid chunk of metal. Nothing gives and any clearance would have to be compensated for by the length o the lifter, an adjuster on the rocker arm, or a shim on the top of the valve the rocker arm was working against. Add in the port and things change. At rest on the low side of the lobe (when the valves are closed), oil that had been captured in the lifter is allowed to escape. The spring under the piston allows any mechanical pressure caused by the valve spring allows it to move. The valve spring pressure overcomes the lifter spring pressure and the valve remains closed during the compression and ignition stages of engine operation. When its time for the valve to be opened, the cam lobe will push up on the lifter and its port will close by a machined groove in the bore it is operating in. Once again it becomes a solid object that can open the valve against the valve spring pressure. As the cam rotates around and the lobe is no longer trying to lift it, the lifter is pushed back down into its bore, the port is uncovered, and the captured oil escapes. Any wear that may occur in the valves, the cam, the rockers, etc., is now compensated for by the lifter's piston and the spring that is keeping it floating in the bore of the lifter. You've probably heard the expression that an engine had a 'collapsed lifter.' This is usually associated when talking about an engine whose valves are rattling pretty god during initial start up in the morning, or after sitting for an extended period of time. This is when the engine was stopped and one, or more valves were in the open postion. This would be when the port in the lifter was closed off, so the lifter should be a 'solid chunk.' What's happened is that the lifter piston-to-bore clearance has worn, and the catured oil was allowed to escape. The valve that was opened is now closed, or partially closed, and the only thing keeping pressure on the valve stem is the spring under the piston in the lifter. Once the engine is started, excessive clearance will be present until the lifter can fill with oil to, once again, make it 'solid' so it can open the valves like it should. There are several variations of where the hydraulics come into play in this type of system, but the bottom line is that the hydraulic lifter compensates for valve train wear so adjustments are no longer needed. A quick and dirty explanation, but hope this helps. Guy A16 Richmond, VA -----Original Message----- From: "Lloyd F. Rauschkolb" Sent: Jan 10, 2005 6:48 PM To: DSN_KLR650@yahoogroups.com Subject: [DSN_KLR650] KLR Valves Observation and Question Adjusting KLR valves is probably easy for those that are mechanically inclined I guess, but some of us struggle with it and then wonder if we did it right when we get through. (Don't suggest taking the bike to a dealer, that is just not an option any more). Believe me I would rather do that, but I don't believe for a second that dealers actually adjust the valves, and even if they do, I doubt they do a half ass job of it. I have done it myself a few times, but I just don't like to do it and I always end up wondering if I did it right. Can anybody explain why it is necessary that valves need to be checked/adjusted so often on most motorcycles and never have to be checked/adjusted on most cars? Seems like this aggravating procedure could easily be eliminated for motorcycles like it has been for cars. Lloyd Rauschkolb Gulfport, Ms. List sponsored by Dual Sport News at: www.dualsportnews.com List FAQ courtesy of Chris Krok at: www.bigcee.com/klr650faq.html Yahoo! Groups Links

[Eric L. Green]

> Most cars use hydraulic lifter that acts as the valve clearance adjuster.

Many of those that do not, have hydraulic valve lash adjusters (e.g. Honda automobiles). These require a rocker-arm type setup and result in a tall cylinder head. Given how tall the KLR650 engine already is, you can understand why Kawasaki instead used shim-and-bucket type direct activation of the valves, which is pretty much the simplest most compact mechanism possible -- but one incompatible with hydraulic lifters or lash adjusters.

> I believe there were a few > bikes > (Goldwings maybe) that had hydraulic lifters for a while but now I can't > think of any bikes that use them.

Pretty much all Harleys use hydraulic lifters rather than solid lifters. Most big cruisers with the cam in the crankcase do, for that matter, and those with overhead cams usually include hydraulic lash adjusters to get the same effect. Hydraulic valve lash adjusters become problematic over 7500rpm, but these big cruiser engines can't get there anyhow. Though Honda, with the Nighthawk 750, managed to make it work in a higher-revving motorcycle engine (but note that the Nighthawk 750 was not marketed as a performance bike, thus the lesser performance available with hydraulic valve train was not a bit issue).

> I believe the trade off for a hydraulic lifter is reduced performance at > higher rpms.

Well, this wasn't a problem with the KLR . However, the increased cylinder head height needed to fit hydraulic valve lash adjusters and associated rocker arms into a dual-overhead-cam cylinder head definitely was an issue, given how tall the KLR already is. Either Kawasaki would have needed to move the crackshaft further back and lean the cylinder head further forward and lengthen the wheelbase, or ... well, anyhow, they did nothing of the sort, and instead did the shim-in-bucket trick to make the valve train less lofty. -E

[Fred Hink]

I bet Kawasaki's decision to not use Hydraulic Lifters had more to do with their Bottom Line rather than the top of their head... Fred http://www.arrowheadmotorsports.com http://www.angelfire.com/ut/moab/cmc.html

----- Original Message ----- From: "Eric L. Green" To: "Fred Hink" Cc: DSN_KLR650@yahoogroups.com> Sent: Monday, January 10, 2005 6:52 PM Subject: Re: [DSN_KLR650] KLR Valves Observation and Question Either Kawasaki would > have needed to move the crackshaft further back and lean the cylinder head > further forward and lengthen the wheelbase, or ... well, anyhow, they did > nothing of the sort, and instead did the shim-in-bucket trick to make the > valve train less lofty.

[monahanwb]

--- In DSN_KLR650@yahoogroups.com, "Fred Hink" wrote:

> Most cars use hydraulic lifter that acts as the valve clearance

adjuster.

> These rarely go bad but they do sometimes. I believe there were a

few bikes

> (Goldwings maybe) that had hydraulic lifters for a while but now I

can't

> think of any bikes that use them.

Moto Guzzis built in 2003 or 2004 se hydraulic lifters, at least in the California series of cruiser/tourers. It may be the last year that Moto Guzzi produces a hydraulic valve motor, though. And it is why my new Guzzi (if it ever gets here) is an 02 model, brand new, with mechanical actuation.

[Jeff Saline]

KLR Listers, Just thought I'd post a quick note about some of the long distance advice I've seen here. Some things seen often is whether the doohickey is ok or not, what is the correct setting for a fuel mixture screw, exactly what the best setting is for a suspension, what tires are the best and what tire pressure should be used. Giving definitive advice on any of those subjects is like telling someone how long a piece of string is with out seeing it. It depends on the piece of string. The doohickey may or may not be ok. Some break and some don't. Some springs are in one piece and some aren't. Some are still under tension and some aren't. The only way to know for sure is to open the engine and take a look. It seems like the consensus on this list is the doohickey is normally worth replacing as a fair sample of broken doohickeys or broken or stretched springs have been found. But it doesn't mean the parts in your KLR are broken or stretched or even that they will break or stretch. For the idle mixture screw adjustment. I often read comments from someone saying to turn the screw out 1 3/4 or 2 1/4 or some other such number of turns. That it will make the bike run better. That adjustment is best figured out on each bike. There are a few variables that will make each adjustment unique. A few factors to consider are normal riding elevation, grade of fuel, engine condition, air filter and condition etc. Just cause it works on my bike at 3,200 feet using 85 octane fuel and a No Toil air filter doesn't make the adjustment correct for your bike at sea level with premium fuel and a stock air filter that's dirty. Seems like many bikes come from the factory set to run a bit lean but adjustments to richen the mixture should be made for each bike being adjusted and not just to a set number. I've check a handful of bikes for adjustment setting from the factory and got from 1 1/4 to 1 3/4 turns out on the screw. And they all ran just fine too. Suspension and tires are personal preferences. And sometimes mandated by wallet size. I like my bike the way I have it set up. It works well for me. Others don't care for it so much and prefer their bike set up to mine. Neither of us is wrong. We're just different. A bunch of adjustments and changes are possible on a motorcycle. Some are good and some are not so good. Some depend on personal preference or riding style. Some are safety related and some are not. Some may cause serious problems, some may be a hindrance and some may be an improvement. They only way to know for sure is to try it for yourself. A good starting point is often appreciated. Like being told your mixture screw is probably set a bit lean or your stock doohickey could probably be replaced for better reliability. Or maybe the Kenda K270 tires are pretty good tires for the money but the sidewalls are very flexible and that might cause problems if you have a flat at speed. So... sometimes it's worth considering the source of advice on the list. Just like this. You may or may not agree with what I've just posted. You decide if it's good advice or not. Best, Jeff Saline Airhead # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads.org The Beautiful Black Hills of South Dakota '75 R90/6, '03 KLR650, '79 R100RT, '00 H-D MT-500