I seen this kit aswell. Seems pretty cheap. To bad I wanna put a 4 cyl in mine,[img]i/expressions/face-icon-small-smile.gif[/img]

 

Yamaha Apex motors are cheap, under $3800 right from the dealer. [img]i/expressions/face-icon-small-wink.gif[/img] Thats 1000cc of pure screaming 4 stroke, 4 cylinder power.

 

Sandman,

I went ahead and investigated since wanted to understand better for myself and others. On Ebay, Lisa (Big Bore ad) said there was little room in the cylinder for 105mm (105 thick AL sleeve granted, but not sure about 105 boring like Scooby) and this is a durable option that should support most users requirements. I called JE and talked to John Noonan (google john noonan racing) and he said the same thing, but both were selling JE steel sleeves. They are not specific DS650 experts though, so we will find out from Scooby, an unbiased DS650 high hp expert.

However John Noonan is land speed record for 2 wheel vehicle on big 475hp 1350cc Suzuki (253mph avg), so he had a wealth of information, has designed pistons for 14 years, and knows every type speed enhancer/charger.
John said just $160 JE piston 11.5:1 (also on Ebay) would be excellent for most people, and I may just do that for an inter-period or final solution (Hightower installed a JE piston like this before). John also said custom pistons ($700/4) were $175 each which could do most everything within alloted Custom JE options (without minor fees). John also states he uses Millennium cylinders. Both Ebay vendors and JE sound like an excellent deal.

Millennium works with CP Pistons, which is also a good piston as well, but I will have to be convinced of their advantage over the JE Pistons when discussing a big bore package. After talking with John, I may not bother with the big bore kit (not even the 700cc or 102mm). If I had a charger, he said just juice it up a half psi boost and it would do fine. In fact, for most all applications, he said just the 11.5:1CR JE piston alone would be excellent for cost/benefit for most users (11.5:1 CR max for pump gas).


So known options to date are:
(CP pistons are not listed but should be about same price if can get for Rotax DS650, like Ron Woods)

1. JE piston kit 11.5:1 CR (alone) Ebay $160 - Stock AL wall- 650cc or 720cc. (pump gas)
1a. JE Custom CR/configured Piston (4 required) $175/ea- Stock AL wall- any size cc. (custom)
(CP pistons only require 1 custom piston but don't know price - i.e. included in Millennium Big Bore package - 2a below)

1b. JE piston Standard HPR kit 12:1 CR(alone) $250 - Stock AL wall- 650cc . (Not pump gas)
1c. JE piston Super HRP kit 14:1CR (alone) $400-$415 - Stock AL wall- 650cc or 730cc. (Not pump gas)

2. JE Big Bore Kit (on Ebay) about $550 with machine work - JE steel insert- 720cc. (11.5:1CR pump gas)
2a. Millennium Big Bore kit $465 - bored AL cylinder, nikasil liner - 700cc - Stock AL wall(custom)
2b. Millennium Cylinder Bore customized to your supplied piston $215 - bored AL cylinder, nikasil liner - 700cc. (custom)
(option 2a or 2b, if install AL insert into previous 720 big bore cylinder, add $200).

3. Pami Big Bore (TheBom) about $1800 - AL cylinder insert, nikasil liner - 725cc (known AL re-sleevable by Pami and ERBE) (Assume custom CR)
3a. HPR Big Bore $1900, ODP - AL Casting, (Millennium) nikasil liner - 730cc (Mr. HP just informed me in ALL CAPS that his 730 Big Bores were not condusive to work well with the same diameter AL sleeves, assumed to be due to closer cylinder wall mold tolerances). (13:1 CR Not pump gas, of 12:1 CR Not pump gas with double thick gaskets, or 11:1 CR pump gas with triple thick gaskets)


Current Ongoing Research:

A. Scooby Used Millenium to bore a stock cylinder to 720cc (AL OEM walls nikasiled lined), so we will see how it holds up to a high hp turbo with max 19:1 CR equivalent. Currently all test reports have been excellent - $215 - 720cc. (custom)


So here is a good wide range of excellent alternatives to make everyone happy :-)

 

yjacket I may have misread some of your info, but just in case and just checking to be sure,
are you aware that the stock oem cylinder of the rotax 650 used on both the ds and the funduro are aluminum with nikasil lining and have no steel insert?

 

Hightower,

No I wasn't. The only thing I had read was HPR's big bore list (below) which seemed to be comparing DS650 big bore alternatives, so... Thanks!

Why do I need a big bore now, lol. AL walls from the list below was my main concern. So the list below makes owners yern for feature they already have without the forged piston (mainly) and additional size. Hmmmmm. John the expert racer at JE was 100% right. From $1900+ to $465 and now down to $160. I wonder what cast iron were represented for in the list below???? Maybe a big bore and tractor comparison. The steel sleeves could be JE big bore sleeve.


Here's HPR list that implied it to me:
============================================
New cylinder VS re sleeved cylinder:
1. Horsepower: up to 3% loss by resleeving a plated cylinder
2. Engine life: Cast iron and steel wear 10 times faster <------------------
3. Reliability: Sleeves can slip and turn in the bore
4. Lubricity
5. Cooling: Cast iron and steel don't transfer heat as efficiently <------------------
6. Design: Your cyl was plated for a reason from the factory
7. Strength: boring the stock jug leaves less than 0.080 wall thickness to hold the sleeve and transfer heat
8. Head gasket seal: boring the stock jug leaves little surface for the head gasket to seal
9. Reputation: as of 9/16/05, HPR production cylinders boast ZERO failures since they were introduced

 

Oh you guys are trying to give me the hebbie cheebies huh??oh well getting closer to the build, have a DShead coming in soon, working on the springs soon, might be closer to june or july when I do the 720 kit was aug, so things keep going right may be sooner.........and if I dont have to keep working on the kids quads....dad when do i get a pipe, dad when can I get shocks, dad when can I get a big bore kit?
KIDS CAUSE TORETTES!!!

 

Funny how when the kids where little we couldn't wait till we didn't have to buy diapers or formula anymore. Now with my baby being almost 19 and the oldest is almost 28 I would rather be buying just the diapers and formula. Seems like the older they get the more they cost. lol. =]

 

ERBE,

Someone posted recently how the forged piston was the main performance gain, and not the big bore, carbs, or pipes. I was deceived big time.
At the most, get your kids a forged piston, take their baffles out, OMR CV carb tune up, and you're done! One guy on Extreme put 450r carb in recently and same DS hookups and worked perfect! All power ranges improved, even top end! For $170, eventually you will have to check it out to compare. They are blowing their buddies away with the 450r response advantage and DS650 torque power. Smooth controllable response power.

 

didn't azsand have a 105mm bore with raptor parts once?

 

Azsand and I both had the samcoe 733 kits at one time, 103mm bore 88mm stroke and yes the stroke was done with a short Raptor carillo rod- mine is still running...somewhere...