2019 125 powervalve vs 2018. Differences??? TC125 KTM 125SX

riv187
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riv187
I have a 2018 TC125. Anyone have a 2019 or seen one and powervalve ? Is it the same unit with just a little extra machining to clean it up...or is it really changed?
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DynoDan22
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DynoDan22 9/14/2018 1:01pm
9/14/2018 1:01pm
The '19 125/150 powervalve uses the same actuating levers, main flap, and rotary drums according to the parts fische. The cylinder has a different part number for '19, so I assume this is what they are talking about when they mention "CNC matching exhaust valves for better....". They probably CNC'd part of the exhaust flange/duct for improved flow. That's my guess.
BR8ES
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BR8ES 9/15/2018 7:33am
9/15/2018 7:33am
Are the F1 arms really worth it?
riv187
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riv187 9/15/2018 8:28am
9/15/2018 8:28am
DynoDan22 wrote:
The '19 125/150 powervalve uses the same actuating levers, main flap, and rotary drums according to the parts fische. The cylinder has a different part number...
The '19 125/150 powervalve uses the same actuating levers, main flap, and rotary drums according to the parts fische. The cylinder has a different part number for '19, so I assume this is what they are talking about when they mention "CNC matching exhaust valves for better....". They probably CNC'd part of the exhaust flange/duct for improved flow. That's my guess.
I suspected that,,,and figured if I see a closeup of a 19 cylinder I could hand port polish mine to match. If it was dramatic and big power boost I'd be shopping for new 19 cylinder or whole bike. I haven't had power valve problems with my arms,,,and wonder if just carefully polishing groove the drum rod slips in would be all she needs.
DynoDan22
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DynoDan22 9/15/2018 8:58pm
9/15/2018 8:58pm
I haven't had any powervalve issues on my '18 150sx. Knock on wood. I grease my valve pins and arms religiously every 5hrs with Viperlube (just a thin grease) and all has been good. The majority of the friction is developed between the valve drum/o-ring/cylinder. I suspect that jetting and oil ratio and oil type come into play which leads to some people having issues and others don't. The motion ratio of the arms to rotational movement of the drums is very aggressive and is sensitive to friction at the drum/cylinder. The KTM powervalve system on the 125/150 is like the old '92-'01 CR250 with one main flap valve and two sub-exhaust rotary drums BUT Honda had ball bearings on the sub-exhaust drums which lowered the friction between the drum valves and cylinder.

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BR8ES
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BR8ES 9/15/2018 9:20pm
9/15/2018 9:20pm
I ordered up some F1 arms, cheap enuff I guess. May try the approach above for a bit though.

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