I wouldnt underestimate the performance of a properly built 690 Raptor,they can really hold their own and then some.I have a fully built 690 with about all the internal mods you can get along with a dual exhaust system and i am very happy with mine.I am 6'4" and although i prefer my Baja for comfort the Raptor is not too bad .The bigger bore Raptors dont always out perform the 690 bore so i would consider that.To build a fast Raptor requires a lot of research and and even more money but as long as you buy the right components and have them assembled by a competent builder it can be worth the effort.

 

Let me know what you might need (pm me). 70hp with high 40's to 50tq is very possible on gas with correct head work/carbs/cam and exhaust on a stock bore and stroke. The stock rods are WEAK. There are several replacement options including strokers. The most common builds are 686 (102mm bore stock stroke) and 730 (105mm bore and stock stroke) the 105mm bore needs a new cylinder sleeve and the cases machined to fit it. Some relativly new options are 720 ( 102 mm bore and +4 mill stroke) HotRods offers a drop in kit for the 720 stroker but you are limited to thier piston. Barkers (www.barkersbars.com) has strokers that use off the shelf pistons wich I consider a real plus. I will warn you it ain't cheap! You can readliy get 60hp with stock carbs good port work/valves cam piston and exhaust.

 

Much thanks again for all the real help. When he is ready (tired of refilling his tear offs [img]i/expressions/face-icon-small-smile.gif[/img] ), we will probably look into the 105mm piston. We will have to pull his motor apart to see what kind of work it needs to fit that size piston in. I'm sure we won't be replacing cams and porting, however, you never know. Like DSNUT said, big bore helps mostly down low with the rest stock stuff. That is not really what the raptor needs for us. That is exactly what I want for my DS, thats why everything else on mine is pretty stock.

There has to be some reason most everyone is running only a 686. Plus, yamaha now offers a 700 which I think is only a 686. There must be something. It can't be too hard to put in a 105. ? We'll see.

I definitely don't want to start a "what combo is better" thread. I would never argue a well tuned 690 wouldn't crush a 730. We don't race quads. For us weekend warriors, something like a 730 is cheeper with satisfactory results. You just can't run your mouth.

 

the reason everyone goes to a 686 instead of a 730 is just what scholle posted you have to resleeve the cylinder, the 686 is a bore.

a decent cam, bump up compression with a new piston & some basic clean up porting would be worlds better than doing a 730 with stock cam.

 

Excellent counsel![img]i/expressions/face-icon-small-happy.gif[/img]

 

A tuned 686. Worlds better you say. O.k. I'll look seriously into that route. We will have to look into costs vs. gains. I'm with you though.

I will say that as a big fan of my DS, out of respect to us DS owners, I will not be offering this info unless asked. No need to be having one more mouth with a faster Raptor. However, he is a friend and I'm always here to help. My mind is at least satified where to start.

Thanks again men.