Cam Advance MC Mod. - Kawasaki KLR 650 Forum
2008+ KLR650 Wrenching & Mod Questions For repair, maintaining or modifying discussions related to the newly updated 2008 and beyond, Generation 2 KLR650 Motorcycle.

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post #1 of 92 Old 05-02-2015, 03:59 PM Thread Starter
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Cam Advance MC Mod.

Anyone done this, if so tell us what you think? Do you like the change if any, would you do it again? How many miles with the mod do you have? Dyno info seems hard to come by so i guess seat of the pants will do.
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post #2 of 92 Old 05-03-2015, 02:35 AM
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Type that excact title, or "free power" in the search box,
and a buncha stuff will pop up. There's a whole KLR library here.
Been researching and thinking on this one myself.

This is my son, with whom I am well pleased." ----God
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post #3 of 92 Old 05-03-2015, 07:19 PM
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Food for thought,
The MC Mod advances the Exhaust Cam shaft. The Exhaust Cam Shaft has the Kawasaki Automatic Compression Release (KACR) attached to the R.H. end.

If for NO Other Reason, owners of reluctant Cold Weather/Cold Morning starting 2008 and NEWER KLR650's, Should Consider This Mod!

Case in point, '09 oil burning KLR650 29,435 miles. 88 PSI, Cold Cranking Compression.

Recent Schnitz 685cc rebuild, with valve seats as 'Perfect' as I could justify. OEM gaskets, not the oil leaking 'Hi-Compression' Cometic Gaskets.
MC Modded, (exhaust cam advancement), Freshly assembled per Schnitz Instructions, (As in, I can't believe how DRY they want this thing!) NOT Yet Started (Wednesday 4-29-15)! 124 PSI.

Started instantly! As in, was at TDC compression stroke. 2 full rotations of the engine, 4 Cycles! Down on the 'dead' power stroke, Up on a wasted Exhaust stroke, Down on the Intake stroke (full carb, on full 'choke'), UP on the Compression stroke and Running!

Rode it a 100 miles Thursday evening and changed the oil and filter.

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 84,000+ miles & counting
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post #4 of 92 Old 05-03-2015, 08:26 PM Thread Starter
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I have read allot of posts from several people who have done this mod and nearly all really liked it and noticed the change...7-10% torque and HP. When i check my valves i am going to do this mod!
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post #5 of 92 Old 05-03-2015, 08:46 PM
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Drifter,
Can we ask you, to do a Before and After, Cold Cranking Compression measurement?

How is your cold starting? At what altitude? At what minimum Temps?
All in the interest of KLR science, of course!

Yes, we all appreciate a 'broader' power spread! But we have got to be able to Start It, at 28f. in Silverton, CO at 9800 ft. in August, to enjoy IT. Or, maybe start it at -32f., in the NW territories, on the 'Ice Roads", in March!

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 84,000+ miles & counting
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post #6 of 92 Old 05-04-2015, 09:38 AM
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Quote:
Originally Posted by Drifter. View Post
I have read allot of posts from several people who have done this mod and nearly all really liked it and noticed the change...7-10% torque and HP. When i check my valves i am going to do this mod!
The "MC Mod" reduces valve overlap by 15 crankshaft degrees.

Torque and horsepower increased 7-10 % from idle to redline?

Fantastic. FANTASTIC!

Men of good will doubtless have performed credible dynamometer runs confirming this performance increase; would like to see some charts (beyond the accuracy/precision/repeatability error budget of the dyno) . Besides before-and-after dyno runs, maybe some before-and-after quarter-mile timing tickets?

If this promise of "free power" is valid, then . . . REJOICE! For all generations?

The power increase claimed is not unlike that claimed from the "PCV Valve Mod," also scantily documented. Yet, "perception is reality" with many mods. Nothing against the MC Mod, only wonder--how does reducing valve overlap INCREASE peak power; the reverse is true, regarding conventional valve timing.
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post #7 of 92 Old 05-06-2015, 03:36 PM Thread Starter
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OK, i will do a compression test, it wont be anytime soon few months at least!

I live 131 ft above sea level and its Hot in the summer, sometimes in the winter also, 9000 ft. is nose bleed altitude for me! The way my bike is jetted it would not run at 9k feet! Maybe that is why you have starting problems?

The PCV mod to me seems the wrong thing to do, the pcv creates a vacuum in the crankcase on the upstroke of the piston which would reduce power just like having no vent which would create excess pressure In my opinion the small hole in the airbox is to create a neutral air exchange in the crankcase? This is one mod i am not doing.
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post #8 of 92 Old 05-06-2015, 07:26 PM
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Originally Posted by Drifter. View Post
OK, i will do a compression test, it wont be anytime soon few months at least!

I live 131 ft above sea level and its Hot in the summer, sometimes in the winter also, 9000 ft. is nose bleed altitude for me! The way my bike is jetted it would not run at 9k feet! Maybe that is why you have starting problems?
Drifter,
My personal bike, 1987 -A1, starts fine, runs fine between 4000-13,800 ft, +25 to 95 f.. Might be a tad lean on the mid-range needle at 105f., <4500 ft., but I really didn't like the KLX650 needle, at least on my bike.

My cold cranking compression hoovers in the 100-120 psi range, with tappet adjustments every 10,000 miles. Can't remember it's leak-down reading. CRS!

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 84,000+ miles & counting
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post #9 of 92 Old 05-07-2015, 06:00 AM
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Quote:
Originally Posted by Drifter. View Post
The PCV mod to me seems the wrong thing to do, the pcv creates a vacuum in the crankcase on the upstroke of the piston which would reduce power just like having no vent which would create excess pressure In my opinion the small hole in the airbox is to create a neutral air exchange in the crankcase? This is one mod i am not doing.
Any QUESTIONING of the efficacy of the PCV Valve Mod can get a poster BANNED from one or more motorcycle forums, Drifter! Be very careful about where you express any doubts!

Eschewing the PCV Valve Mod, you deny yourself not only the increased power allegedly available, but also the claimed additional fuel mileage, lower oil consumption, enhanced engine compression braking, and improved ring seating.

The MC Mod may indeed be a valid improvement; I simply cannot understand how the increased power is produced, given the sacrifice of 15 crankshaft degrees of valve overlap . . . cut that's jus ME!
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post #10 of 92 Old 05-07-2015, 10:32 AM
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Originally Posted by pdwestman View Post
Food for thought,
,,,,,,,,,,, Freshly assembled per Schnitz Instructions, (As in, I can't believe how DRY they want this thing!) NOT Yet Started (Wednesday 4-29-15)! 124 PSI.

Started instantly! As in, was at TDC compression stroke. 2 full rotations of the engine, 4 Cycles! Down on the 'dead' power stroke, Up on a wasted Exhaust stroke, Down on the Intake stroke (full carb, on full 'choke'), UP on the Compression stroke and Running!
This little snip-it of information makes me wonder.
"Why couldn't Tom Schmitz and others kick-start their '08 and newer models after spending the time and money to convert?"

I had witnesses/spectators to the ease of start-up.

Maybe this statement belongs in the kick-starter thread?

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 84,000+ miles & counting
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