Author Topic: Stroked and bored 06  (Read 4101 times)

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Offline JEREMYZDEAD

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Stroked and bored 06
« on: April 07, 2010, 06:54:36 AM »
I got the +3 stroker. I was wondering if 98mm overbore was the biggest i can go with out problems boring the stock cylinder? It would make it a 491 or just put out for the athena 100mm bore kit to make it 511.
06 KX450F,04 KX85, 03 KX65, 05 KDX50, 03 YZ125, 06 CRF50, 02 LT-A50

Offline don46

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Re: Stroked and bored 06
« Reply #1 on: April 14, 2010, 10:09:55 AM »
Depending on what you want power wise will make the determination. If you go with the big bore and the stroker it will probably pull a truck but won't rev very quick. I have a stock bored 450 with cams, piston and pipe, and a 450 with the Athena 100mm big bore cylinder, the stocker will run circles around the big bore. So again what is it you want to accomplish?
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Offline BDI

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Re: Stroked and bored 06
« Reply #2 on: April 14, 2010, 10:36:00 AM »
When you do stuff like this It kinda has a snow ball effect. If you big bore and stroke it then you will want to put bigger valves in it and port the head to take full advantage of the new displacement. Then you probably are going to want to bore your carb out to flow enough air to feed your new engine. I just went through all of this with a yfz450. You know what goes a long way towards making a four stroke fast is compression and good fuel.
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Re: Stroked and bored 06
« Reply #3 on: April 14, 2010, 11:56:03 AM »
When you do stuff like this It kinda has a snow ball effect. If you big bore and stroke it then you will want to put bigger valves in it and port the head to take full advantage of the new displacement. Then you probably are going to want to bore your carb out to flow enough air to feed your new engine. I just went through all of this with a yfz450. You know what goes a long way towards making a four stroke fast is compression and good fuel.

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Offline JEREMYZDEAD

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Re: Stroked and bored 06
« Reply #4 on: April 14, 2010, 06:12:26 PM »
The crank seized on me so I bought the stroker for the same price as the stock length. I also have 2 old jugs that are just sittin around so I was thinking resleeve. This is mainly for riding single track up in the mountains, hill climbs, mud and rocks.
06 KX450F,04 KX85, 03 KX65, 05 KDX50, 03 YZ125, 06 CRF50, 02 LT-A50

Offline hughes

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Re: Stroked and bored 06
« Reply #5 on: April 26, 2010, 12:19:40 AM »
I got the +3 stroker. I was wondering if 98mm overbore was the biggest i can go with out problems boring the stock cylinder? It would make it a 491 or just put out for the athena 100mm bore kit to make it 511.

Please correct me is if I'm wrong, but the +3 stroker is a longer stroke than stock? With a longer stroke the engine will not rev out as fast but pull like a train on top end? 
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Offline JEREMYZDEAD

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Re: Stroked and bored 06
« Reply #6 on: May 03, 2010, 03:07:30 PM »
The head is port and polished with the inserts. I lost some of the bottom end because of it. If not couldn't I just change gearing? When I put the +3 in there.
06 KX450F,04 KX85, 03 KX65, 05 KDX50, 03 YZ125, 06 CRF50, 02 LT-A50