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Discussion Starter #1 (Edited)
So, I took apart an '09 oil burner today. From Billings, MT.
29,434 miles, been an oil burner since day one.
Owner 'suggest's' that it had been rebuilt by Billings Kaw. Dealer back when, under warranty. (No Record of such by Kawasaki.)

There was very little, if any evidence of previous disassembly! Which is a good thing in my book!

So here is the 'weird' thing. The second ring has what looks to be an "oil rail" installed Under the second ring.
The second ring has a 'dot' on the top side!??? Non OEM! Who's ring set is THAT! Hastings or who? ???????

Original bore size, Front to Rear, 3.9370 inch (Absolute MINIMUEM) . MINUS .003 inches side to side, 3.9343 inches (Under-size), side to side!!! Talk about an 'out of round' cylinder! This is IT! .0027" Under-size, side to side? NUTs!

But, which ring company is 'supplying' a rail, to be installed Under the second ring of an OEM piston? (Still didn't fix the oil consumption.)
 

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Discussion Starter #3
Schnitz 685 kit and cylinder will be heading to Matt, at Import Auto Machine Shop today.
Eagle Manufacturing was on Back Order. :( Oh well.
 

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Discussion Starter #5
Sandstone,
Sorry, I personally can Not Do Pics! Nor do I even really want to.

What few pics or vids, appear with any of my postings are thru the courtesy of friends!
I do try to not 'impose' anymore than absolutely necessary.
 

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Discussion Starter #6
Well, the job is done.
Ben, the owner of this '09 rode it home to Billings, MT. yesterday afternoon.
Talked with him this AM. Likes the "feel" of it. Probably going to change back to Stock gearing. Is currently 14-43, he really doesn't know 'why'?? But was probably about 15,000 miles back, when new chain and sprockets were installed in Billings.

Which brings me to this question. How bloody long, can a KLR650 Gen2 run, with the stock Doo-Hickey LOCKING BOLT LOOSE? With-out turning into a hand-grenade, like some we have seen on the net?

The locking bolt was so 'grooved', I had no choice but to change it, even if I'd of added the flat washer to the EM doo, I'd of wanted to change the locking bolt. But I DID have to re-machine the flat surface of the inner cover. Where the "cycling" Doo had worn a pair of "Trenches" into the aluminum inner cover!

Sorry Guys, No Pics.

Ben says the oil window is 100% full after his 300-350 mile ride home.
I did 'scribe' his oil window at the 2 quarts filled mark, when I did a 100 mile 'break-in' oil change, so he could seen when it was a full pint Low. Before this work, he'd of been adding oil. I'll give 99% of the reduced oil consumption to the Schnitz 685 kit at this time. Maybe we will all get to hear about long term useage, maybe not!
At Bens allowance, after reading lots of Our postings, I drilled all three banjo bolts. And tapped the oil filter Cover, for a 'Restrictor' Orifice. But did NOT install one.
 
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I'm not going to fix my oil burner until I've given all the oil mods a good shake.

When am I going to get some numbers up on the modded cover????!!!

This week, this week for sure. Dang it.

Tom
 

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Discussion Starter #8
Ben from Billings MT is off to Alaska.
 

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Discussion Starter #9
BU, Bu, Bum, Bump!
Been 5 years already, wow.
Ben has had me do a couple minor servicings to his bike, while on his way thru my area on tour. This past summer we wished that he'd of had time to allow for valve tappet inspection & adjustment. But he hadn't allowed time for cold engine.

Anyways bike currently has 49,773 miles. 10,000 More than I'd recommended be allowed, "but hey, it runs good. Just a little reluctant to start up."

Last spring he had forgotten the bike was running on Full Cold Start enrichener in his driveway for 'awhile'. Melted 1 thumb sized hole into clean side of air box just ahead of mid-pipe gasket. And another thumb sized hole above the heat shield, also in the clean side of the air box and the edge of rear inner fender. Which I found & RTV silicone closed, last summer.
Replaced both extreme heat damaged exhaust pipe gaskets. And Ben was off to California.

Fast Forward to Now,
WOT / CC Compression was 97 psi, Pretty Good.
Remove valve cover. I had performed the MC Mod back in 2015.
Which was one of the 'newer modifications' which some owners wished to try. And which I knew could UP the CCC on engines which had too late of timing on the exhaust KACR, which Bens engine had.

Anyways,
Intake valves were at < .006" & .008". Great we caught the holes in air box before it breathed much dust.
But the Exhaust valves were at .0000 & <.003" ? What the heck?

Re-adjusted valve tappets to <.008 & still .008 on Intakes. Exhaust re-adjusted to .010" & >.009.
Standard cam shaft timing yielded 82 psi of WOT /CC Compression.
Re-remove EX cam & grind/polish .016" off of KACR pin. Re-check CCC, 125PSI Great.

I've got a pretty good hunch as to what caused the exhaust tappets to close up so much.
Do you?
 

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Just an MC mod question: Does advancing the exhaust cam crack open the exhaust valve (via KACR) SOONER or LATER on the compression stroke, compared to stock valve timing?

Seems like earlier valve opening would result in lower cranking-rpm compression pressure than later to me, but . . . I could be horribly wrong.

Academic consideration, anyway, given the many pros of the MC mod over its cons (according to some) The adjustable camshaft sprockets manufacturer ("KLR somebody" username, I think; I forget) in Texas wasn't a fan of the MC mod, in my communication with him. I think it's fair to say opinions vary on the MC mod benefits (if any) among KLRistas.
 

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Discussion Starter #11
The MC Mod allows the KACR to both open & Close the RH exhaust valve earlier, during the 4 stroke cycle of the engine.
The Closing point in crankshaft degrees is the only important number for the KACR. Lift height is not of much importance either.
The KACR is Only Active during the starter motor or kickstart speed of the engine. The KACR will Not be active at any actual running speed of the engine.
 

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Discussion Starter #12
The adjustable camshaft sprockets manufacturer ("KLR somebody" username, I think; I forget) in Texas wasn't a fan of the MC mod, in my communication with him.
Do you recall one of KLRChris s primary dislikes of the MC mod?
 

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@Damocles,
Visualize it this way:

Uh, never mind. I didn't get it right the first time. I'd better be silent and thought a fool...

Whew! My head hurts...
 

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I'm not big MC mod guy (particularly as I have Gen1's) but though degreeing the cams has benefits, I tend to think they aren't terribly significant either, expecially given the cost of the adjustable cam gears.....actually they don't show up as a product anymore.

2 cents.
 

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Sometimes it isn't so much about increasing the peak values as it is about moving them to a more suitable point in the powerband. That can be done by making some changes to the valve timing via a set of adjustable cam gears. Making more power is more complex than tinkering with valve timing, as valve timing is a small part of the whole process.

Adjustable cam gears are William Tell, a bolt, a crossbow, a boy, and an apple. The MC Mod is a baseball bat and a forehead.
 
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Discussion Starter #16
With the stock set-up, the KACR does open sooner and close sooner than the MC Mod positioned KACR.
Tom I'll suggest that is in-correct.

The MC Mod advances the Ex camshaft, so that the whole exhaust cycle opens sooner. Which KLRChris measured to allow Increased Exhaust Heat during running cycles.
But the MC Mod also allows the KACR to close the de-compression phase sooner (piston further down the bore, during up-stroke of compression stroke) to trap more volume to create more CCC at start-up speeds ONLY.
 

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Dammit! You know, I wrote that three different ways and I still got it wrong! And my head still hurts!

I'm going to give up on it.
 

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Kawasaki 10W-40!

My experience with the MC mod was that it made the engine quite a bit harder to start and almost eliminated engine braking.

The engine becomes harder to start because it advances the period during which the KACR operates, forcing it to operate when far less induction is happening. The KACR is deactivated just about when the real induction starts to happen, resulting in a lot more charge being compressed. That makes for a greater effective compression ratio. That was a stone-cold bitch when it was ~30°F.

A lack of engine braking is not something I can live with. All things considered, and not noticing any real change in power, I reversed that mod.

I degreed my cams to move the peak power up in the powerband a bit.
Increased cranking compression is seen when the MC mod has been done.

As you note, everything related to the exhaust valve timing happens earlier (including the closing of the exhaust valve by the KACR).

The conjecture on why the MC mod produces greater cranking compression was that, simply, the KACR's duration is at a time when the piston is coming up from bottom dead center, so there is not as much vertical motion in the piston (because the crank pin is moving largely sideways). It is doing its job of reducing compression when not much compression is going on.

Conversely, with normal timing the KACR is active 15° later in the compression stroke when there is more vertical motion of the piston (becasue the crank pin is moving largely upwards). Proportionally, more compression is released because more compression is happening.

I think if one were to lay out the opening and closing of the valve by the KACR under both conditions, it would be apparent that, in the layout of the MC mod timing, the piston had less vertical motion during the KACR-active portion of its stroke.

Tom
 

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Discussion Starter #20
The oil question was a joke, of course.

Tom said, "forcing it to operate when far less induction is happening."

That can't be, because the intake induction has finished by 69 degrees ABDC. And the KACR should engage the RH exhaust valve tappet after the intake valves close (during start-up only).
I find the engines with mis-timed or what I've previously referred to as Over-active KACRs to much easier to cold start when the MC Mod has been performed, because it increases the CCC. I've only performed the MC Mod on 1 other healthy KLR685 and had to reverse it because of too much CCC nearer sea-level in Baja, CA. It was causing the starter clutch to slip then grip, with really ugly noises. And he didn't like the reduced engine braking either.

Closing the RH exhaust valve sooner during the start-up compression cycle by either advancing the entire camshaft, grinding a specific amount off of the top of the kacr pin or by completely eliminating the KACR will undoubtedly increase the effective cold cranking compression. But none of them increase the running compression.

You yourself measured about 178psi of WOT / CCC with your KACR totally dis-engaged by a piece of fuel hose under the spring, IIRC. That much compression would be very hard on the starter system at 30F, that is WHY there is a KACR.
You then measured about 105-115 psi with the KACR active. Did you ever measure the CCC with the MC MOD exhaust cam timing on that same engine piston?

"That makes for a greater effective compression ratio. That was a stone-cold bitch when it was ~30°F.", Tom said.
I need to ask was this with your old piston or the 11:1 Wossner piston?

One of the keys to great start up of a cold KLR650 is to have over 100 psi of CCC. And one of the keys to having a strong running engine is to have over 170 psi of running compression. Good piston, rings, cylinder, valves & valve seats ensure the later. A properly timed, active KACR ensures the former, but only when the first 5 are good.

But we have gotten way off topic here.


What could I possibly attribute the accelerated exhaust valve wear to, on this engine?
 
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