Sp cams

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Miles
zxr400 oc member
zxr400 oc member
Posts: 498
Joined: Wed Apr 30, 2008 11:00 pm
My Bike: ZXR 400 L3
Location: Bangor, Northern Ireland

Sp cams

Post by Miles »

Quick one. Does fitting adjustable cams require a different ignition disc on the crank to be fitted?

I've had the cams dailled in professionally so no problems there with engine timing but just before I totally blame my carbs (see other post) just wanted to check

Apart from the carbs it's the only other change I've made to the bike
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banner001
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My Bike: ZXR400 L4
Location: Nuneaton

Re: Sp cams

Post by banner001 »

not necessarily, all a new ignition rotor would do is send a slightly different fixed position signal to your cdi, i.e. it might be advanced a few degrees over the standard rotor, if this was the case your spark plugs would fire a little bit before they curently do so, the amount of aditional ignition advance would be set by your cdi as normal.

what you would be best to do would be to get a programable ignition, the ignitek ones are about £300, then you could degree your cams for the amount of valve overlap, and valve timing that you want and set your ignition curve so it produces the best possible power band for your engine/carbs/exhaust setup.

im assuming that you have set the cams to align pretty much with how they were set before, in terms of BTDC opening and ATDC closing, and a roughly similar amount of valve overlap, if this is the case then my first statement is true, if you have massivly altered the position of the cams to the piston then you might need to look at a custom cdi
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
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