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Stroker/Big Bore Info Confirmation

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Ok, here is the deal. I have a buddy with a quad (LTZ 400) that had me put on an Athena Overbore Kit when we redid his topend last fall. Well he jacked up the tranny and we had to split the cases. Now he wants to add a stroker crank too. I just want to make sure I got the specifics right before he spends his money.

What he has:

Some sort of Mikuni Racing Carb. Not stock and bigger.

Athena with the 434 kit 94mm bore

Hot Cams

Yosh Exhaust

K&N air

No porting/stock valve springs

Is this what we need to do to add the Hot Crank stroker?

Get Eddies spacers

Relieve the skirt to clear the block (I want to use the 3 ring piston that comes with the Athena kit)

Assorted gaskets

Dimple head pipe if needed.

With the stroker, there is no change in the crank/cam relationship right?

What kind of power improvement is he gonna get? Best guess is fine.

Thanks. Im doing all of this knowing Ill have to tear into my DRZ400s at some point.

I have read all of the posts but they are kinda running together in my head:confused: :)

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Get Eddies spacers

correct

Relieve the skirt to clear the block (I want to use the 3 ring piston that comes with the Athena kit)

wrist pin boss,not skirt.

Assorted gaskets

yes

Dimple head pipe if needed.

radiator is easier to dimple,but i dont think its a issue on a quad.

With the stroker, there is no change in the crank/cam relationship right?

wrong

What kind of power improvement is he gonna get? Best guess is fine.

4 hp peak almost non after peak with doing the rest of the mods to support 470cc's

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Ok, I understand the piston boss clearance and I understand the radiator clearance part. Pics help for sure.

Now I am lost on the cam thing. Ive used degree wheels in cam installs in cars to verify cam timing and did the button thing on the cam gear to change the cam timing to get a different power characteristic. I dont have a degree wheel small enough for a bike. How does the stroker affect cam timing? Isnt cam and crank position all relative? I am sure it is obvious, but I am missing it.

Thanks for the quick replies.

Eddie what is a link to find those plates of yours.

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Quote:

With the stroker, there is no change in the crank/cam relationship right?

wrong

Not to hijack ,but I'm putting in a stroker this weekend ,and do I need to redial my cams/sprockets ? - Never heard about this before

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yes,you will.

you will need to redegree to 108 intake 104 exhaust.

Thanx Eddie ,guess you saved me some expencive valves:thumbsup:

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yes,you will.

you will need to redegree to 108 intake 104 exhaust.

Just checked the specs of my current hc. intake 107.5 dg , ex 104,5 dg .

Is there any need to change ,or will it be ok ?

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when you ad the spacer it alters the cam timing.

:)

guess I owe you a couple of beers now:thumbsup:

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