Valve spring kit, 1 LEFT

cjwell

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Guys I have one let on the shelf. My supplier is shut down, not sure when I'll be able to have more. If you want it get it now. Respond on here first before placing the order so I know who get's it fairly. Thanks and stay safe!
 

AMv8(1day)

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Has anyone gotten any response from @cjwell? I’d like to start a 390 build on my 2021 Husqvarna Vitpilen 401, but it looks like support for the 390 platform has dried up. No Valvetrain kits, aftermarket Cams, Big Bore pistons, little interest from ECU companies in testing Husqvarna support…
 

kostean

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Investigated already during last year and looks that at the moment the only parts you can obtain for the valvetrain for O365 are the TI-retainers and then performance cams what DC Racing has on sale.

As Cjwell claimed the OEM springs are too weak to accept more aggressive cam based on his tests, I have even avoided going to have that modification being made. Besides, there lacks any reliable dyno data on what positive performance gain might the performance cam to bring.

Pitty overall- have 2 CUP bikes for racing and pretty much prepare both of them for all more important race events as 390 engines is just that darn unreliable, especially on the top end part of ii (well, last race also the alternator suffered critical damage).

:rolleyes:Then again, I saw 2020 Yamaha r3 engine with a mere 1900 km on it blowing up last month with a rod through the engine case. Of course, it had the GYTR kit on it and heck tuned out of it, so from that side 390 can be usually fixed with a couple of hours when you have head gaskets stocked up.
 

kostean

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@tylercarbone - hey, that is a good reference, I was not even aware there has been such an improved cylinder head been developed by GrayArea (y). That does go to my shop-list for sure if i come up with a decision to continue racing KTM anymore due to the immense unreliability of that engine as the last 2 seasons have proven or to move over to Kawasaki 400 what appear to demand only fuel, tires and oil.
 

KTMasean

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Is that not the Kawa that doesn't brake?


@tylercarbone - hey, that is a good reference, I was not even aware there has been such an improved cylinder head been developed by GrayArea (y). That does go to my shop-list for sure if i come up with a decision to continue racing KTM anymore due to the immense unreliability of that engine as the last 2 seasons have proven or to move over to Kawasaki 400 what appear to demand only fuel, tires and oil.
 

Superpacman13

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I usually try to not comment on Chad's side of the fence but want to clarify that the cylinder is an OEM part that is manufactured differently then the cylinders that come with our bikes that I install a fire ring into. I don't have any foundries pumping out cylinders for me (yet)
 

Karfanatik

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Question. With the goal being ultimate reliability, I assume you would have to get the JE piston, ti retainers, valve kit, and cylinder w/fire ring? Anything else that should be considered before going in and start upgrading things?
 

kostean

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I did just notice that the SSP300 kit has actually few elements included that might be worth of consideration with heavier valves. One of such is the 1,0 mm preload compensation washers for valve springs.

@Superpacman13 - what do you say, would you consider these heavier valves to work ok with OEM springs with TI-retainers or could it make sense to put even some more preload for these springs in place as there must be a reason why KTM engineers have added more preload as part of the kit.

1631606964673.pngbe ok
 

Superpacman13

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The preload can be achieved through a shim if using an OEM retainer or the Ti retainers achieve the same thing. Its more to compensate for the increase in RPM than any other purpose. The valves will float if left stock above 10500
 
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