rough at 4500rpms

[Eric Haszlakiewicz]

I recently rode my klr from houston to chicago at the blazingly fast average speed of 45 mph. (argh, 30+ hours ) This is due to the fact that the bike won't go faster than about 60mph, no matter what. When it gets going fast, and I open the throttle up to go faster, it starts lurching as if I were running out of gas. It's also a bit low on power, even at slower speeds. I noticed someone else had what seems to be similar problems and the advice giving to him was to check the timing. I assume this is done by opening the small plastic cap on the crankcase to see the timing mark and attaching a timing light. If the timing is off, how do I adjust it? While in houston, I took the bike to a mechanic who looked like he was doing a compression test, then a leak down test. However, he didn't align the cams so the valves were closed, nor did he do anything to disable the KACR. Is it actually possible to get any kind of meaningful results if you don't do that? He did determine that some pressure was leaking into the crankcase by opening the oil filler cap and noticing that there was some air coming out. Would this be due to the rings on the piston being bad? If I pull the cylinder head apart will it be obvious if they are not sealing correctly? Finally, just as I was almost home, the bike starting clanking loudly if I gave it too much gas, instead of just lurching. Perhaps the KACR kicking in? Or something else I should worry about? (it was about the same time the outside air temp dropped by 15 degrees in the space of 30 seconds) thanks, eric

[Thor Lancelot Simon]

On Tue, Jul 08, 2003 at 03:09:26PM -0500, Eric Haszlakiewicz wrote:

> > Finally, just as I was almost home, the bike starting clanking loudly > if I gave it too much gas, instead of just lurching. Perhaps the KACR > kicking in? Or something else I should worry about? (it was about the > same time the outside air temp dropped by 15 degrees in the space of 30 > seconds)

I should also note that in the last month or so, we did the following while chasing other gremlins with Eric's bike: 1) Replaced battery (which was bubbling even after several hours' rest!) 2) Replaced spark plug 3) Disassembled carb completely and cleaned carb 4) Thoroughly cleaned gas tank, fuel line, petcock 5) Replaced coasting enricher spring in carb, which had been left out (!) by previous owner in some mystery maintenance operation. 6) Cleaned and oiled air filter. I'm sure Eric will contradict me if it's not so, but I believe after #5, the bike ran pretty well for a couple thousand miles until the current evilness ensued -- so it's probably not the battery, plug, fuel tank, or carb, at least... Thor

[rm@richardmay.net]

On Tue, 8 Jul 2003, Eric Haszlakiewicz wrote:

> I recently rode my klr from houston to chicago at the blazingly >fast average speed of 45 mph. (argh, 30+ hours ) This is due to the >fact that the bike won't go faster than about 60mph, no matter what. >When it gets going fast, and I open the throttle up to go faster, it >starts lurching as if I were running out of gas. It's also a bit low on >power, even at slower speeds.

When is the last time that you cleaned your air filter? RM

[rm@richardmay.net]

On Tue, 8 Jul 2003 rm@... wrote:

>When is the last time that you cleaned your air filter?

Didn't see Thor's reply in time... Try swapping carbs with a known-good KLR?

[Tengai Mark Van Horn]

At 3:09 PM -0500 7/8/03, Eric Haszlakiewicz wrote:

> I recently rode my klr from houston to chicago at the blazingly fast >average speed of 45 mph. (argh, 30+ hours ) This is due to the fact that >the bike won't go faster than about 60mph, no matter what. When it gets going >fast, and I open the throttle up to go faster, it starts lurching as if I >were running out of gas.

My first guesses are: 1) Fuel petcock vacuum leak leading to starvation at higher speeds 2) air leak in the topside of the carb I had the same symptoms on the way back from Florida a few years ago. It was choice #1. In a hotel parking lot, I took apart the petcock, removed the spring and coated the flanges with a skin of Copper RTV silicone and it's been fine ever since. Mark

[Eric Haszlakiewicz]

On Tue, Jul 08, 2003 at 04:28:42PM -0400, rm@... wrote:

> > On Tue, 8 Jul 2003 rm@... wrote: > > >When is the last time that you cleaned your air filter? > > Didn't see Thor's reply in time...

cleaned the air filter since then as part of trying to figure out why the bike is running so poorly.

> Try swapping carbs with a known-good KLR?

nope, but I've had three different mechanics look at it (taking it completely apart) and it's looked ok. Completely clean, jets clear, needle straight, diaphrams unbroken. I'll try it anyway, but I don't think it'll do much good. eric

[Devon Jarvis]

Eric Haszlakiewicz wrote:

> > While in houston, I took the bike to a mechanic who looked like he was > doing a compression test, then a leak down test. However, he didn't align > the cams so the valves were closed, nor did he do anything to disable the > KACR. Is it actually possible to get any kind of meaningful results if > you don't do that?

I guess you could find TDC by listening for the escaping air, and by feel with a wrench on the crankshaft.

> He did determine that some pressure was leaking into the crankcase > by opening the oil filler cap and noticing that there was some air > coming out. Would this be due to the rings on the piston being bad? > If I pull the cylinder head apart will it be obvious if they are not > sealing correctly?

Pressure leaking into the crankcase during a static leakdown test, or during a compression test? If it was during a compression check then the mechanic is a dunce- the crankcase volume on a single changes by the same amount at the displacement with every revolution, they all blow out the oil filler if you leave the cap off. If it blew into the crankcase during a leakdown test, this would be rings. You would hear the leakage at the exhaust or carb, if it was valves. If the head gasket was bad I would think you'd see the leakdown in movement in the coolant, with the radiator cap off

> Finally, just as I was almost home, the bike starting clanking loudly > if I gave it too much gas, instead of just lurching. Perhaps the KACR > kicking in? Or something else I should worry about?

The KACR works by RPM, throttle position would have no effect. I don't know what caused the noise you describe. (it was about the

> same time the outside air temp dropped by 15 degrees in the space of 30 > seconds) >

I doubt this had anything to do with it. Maybe something is wrong with the ignition (since you and Thor have sorted just about everything else). What does the plug look like? Has anyone checked the ignition timing with a strobe light? Devon A15-Z -- "It's a troublesome world, all the people who are in it, are troubled with troubles almost every minute" Dr. Seuss

[Devon Jarvis]

Eric Haszlakiewicz wrote:

> > > Try swapping carbs with a known-good KLR? > nope, but I've had three different mechanics look at it (taking it > completely apart) and it's looked ok. Completely clean, jets clear, needle > straight, diaphrams unbroken. I'll try it anyway, but I don't think it'll > do much good. >

Your time might be better spent examining the wiring from the stator to the CDI (quick and cheap), also try swapping CDIs (also quick and cheap) and as an absolute last resort swap out the stators. Devon -- "It's a troublesome world, all the people who are in it, are troubled with troubles almost every minute" Dr. Seuss

[Eric Haszlakiewicz]

On Tue, Jul 08, 2003 at 04:47:30PM -0400, Devon Jarvis wrote:

> Pressure leaking into the crankcase during a static leakdown > test, or during a compression test? If it was during a > compression check then the mechanic is a dunce- the > crankcase volume on a single changes by the same amount at > the displacement with every revolution, they all blow out > the oil filler if you leave the cap off. > > If it blew into the crankcase during a leakdown test, this > would be rings. You would hear the leakage at the exhaust or > carb, if it was valves. If the head gasket was bad I would > think you'd see the leakdown in movement in the coolant, > with the radiator cap off

during a static leakdown test. We didn't try taking the radiator cap off so I don't know if there's any problem there. If there was leakage across the head gasket I should end up with gas in the coolant?

> I doubt this had anything to do with it. Maybe something is > wrong with the ignition (since you and Thor have sorted just > about everything else). What does the plug look like? Has > anyone checked the ignition timing with a strobe light?

I'm going to check the ignition timing shortly. The plug is mostly clean (it's almost new), but with a little bit of white deposit. (or at least that's what it looked like in houston: I haven't looked at it since then) eric

[Devon Jarvis]

Eric Haszlakiewicz wrote:

> > during a static leakdown test. We didn't try taking the radiator > cap off so I don't know if there's any problem there. If there was > leakage across the head gasket I should end up with gas in the coolant?

I guess it depends on how the gasket goes. You could get oil in the coolant, coolant in the oil, or loads of white smoke from coolant in the cylinder. Doesn't sound like your problem. If the bike starts and idles well it's not likely that there is a serious mechanical problem. Of course worn-out rings isn't a "serious mechanical problem", it's a consumeable due for replacement. But your symptoms don't sound like worn rings.

> I'm going to check the ignition timing shortly. The plug > is mostly clean (it's almost new), but with a little bit of > white deposit. (or at least that's what it looked like in houston: > I haven't looked at it since then)

White stuff on the plug makes me think Mark Van Horn is right- fuel starvation. What does the petcock screen inside the fuel tank look like, are you using an inline fuel filter, have you tried replacing the fuel line and vacuum hose with new fuel-injection hose from an auto-parts store (routing both hoses without any kinks, the shortest route possible)? Does the problem get worse when the bike is warmed up, or does it improve slightly when the bike reaches operating temp? Have you tried putting the choke on full, does this make the problem worse or better (if gas isn't getting to the carb in the first place this isn't a useful diagnostic tool, but it's quick and free). Good luck. Devon -- "It's a troublesome world, all the people who are in it, are troubled with troubles almost every minute" Dr. Seuss