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aao9y
03-04-2010, 08:26 PM
what about big bore kits. are they realy necessary.

bradley300
03-05-2010, 08:48 AM
if i did it over again i would have put a pipe and decent air filter on mine and left it at that. the electrical system sucks and having to constantly worry if the battery is going to be strong enuff to start the hi comp motor this time and the hassle of keeping it on a battery tender at all times wasnt worth it to me. i raced xc were power isnt everything anyway

aao9y
03-05-2010, 05:52 PM
ok thank i run the worcs series so im just woundering what to do to the bike.

QuadJunkies
03-09-2010, 06:15 PM
Alex, with your power to weight ratio, you should be just fine without one for awhile ... ;) IT was nice meeting you and your Dad at Primm. :)
I guess we will be a guinea pig on how reliable a BB is in WORCS . lol :p :uhoh:
I do have to agree on the battery though, Brandons has a nice drag to it .lol

bradley300
03-10-2010, 08:42 AM
Originally posted by QuadJunkies
Alex, with your power to weight ratio, you should be just fine without one for awhile ... ;) IT was nice meeting you and your Dad at Primm. :)
I guess we will be a guinea pig on how reliable a BB is in WORCS . lol :p :uhoh:
I do have to agree on the battery though, Brandons has a nice drag to it .lol

SMS was doing some thinking and he thinks a 300ex battery will do the trick, apparently its a good amount stronger than the raptors. you should be able to buy the 300ex battery, tray and the rack it sits in and mount it in the same place it goes on a 300ex, all you need to do is make some mounting brackets. worth a shot;)

QuadJunkies
03-10-2010, 09:21 AM
Originally posted by bradley300
SMS was doing some thinking and he thinks a 300ex battery will do the trick, apparently its a good amount stronger than the raptors. you should be able to buy the 300ex battery, tray and the rack it sits in and mount it in the same place it goes on a 300ex, all you need to do is make some mounting brackets. worth a shot;)
Thanks for the suggestion Bradley! I will let Troy know to check it out .
So far were pretty pleased with Brandons . :)

aao9y
03-10-2010, 05:55 PM
that sounds like a good idea:)

QuadJunkies
03-10-2010, 06:51 PM
Hey Bradley, we just checked into the 300ex battery and the Battery company we called on both battery specs said its rated less than the Raptor 250's was ??
They did find a battery that would work better but it would require a completely different airbox. The battery would be too tall . Bummer ....

manco47
03-13-2010, 04:34 PM
Try a yfz 450 battery its a tight fit but does fit in the stock box. It starts ours every time and a lot faster then the 300ex on the line. And we haven't had to but the charger on since we put it in 2 races ago.

jakes
03-14-2010, 12:49 AM
I fitted the 06 YFZ battery and it starts every time. It is a tight fit but works well.

My biggest problem with the big bore stroker was the head bolds are too short and needed replacing with longer stronger ones. Striped 2 bolds casing thread when trying to torque them. Did anybody else had this problem?

QuadJunkies
03-14-2010, 10:21 AM
Originally posted by jakes
I fitted the 06 YFZ battery and it starts every time. It is a tight fit but works well.

My biggest problem with the big bore stroker was the head bolds are too short and needed replacing with longer stronger ones. Striped 2 bolds casing thread when trying to torque them. Did anybody else had this problem? did you say yours is stroked ? We have been problem free so far - knock on wood. Lol
I was told repeatedly that using that high of an out put was not good to do . We called battery company and asked what we could upgrade to safely also .... They said there wasn't anything they could find so far ????

jakes
03-14-2010, 11:44 AM
When we contacted our local Yamaha dealer we discovered that the 2009 Raptor 250 and the 2009 YFZ 450 actually use the same battery. However the 06 YFZ battery(GT7-B4) only have a little more ampere.

Yes, our big bore is stroked. After the motor got hot (2 hours xc racing) the thread in the aluminum case at the bottom striped, because the head bold could not reach far enough down into the thread as it was suppose to, and then with the bigger compression of the stroker it just gave way at the weakest spot.

Other than the bolts that stripped we were also very lucky so far - 3 races complete and the everything else is keeping up very well.

QuadJunkies
03-14-2010, 12:00 PM
Originally posted by jakes
When we contacted our local Yamaha dealer we discovered that the 2009 Raptor 250 and the 2009 YFZ 450 actually use the same battery. However the 06 YFZ battery(GT7-B4) only have a little more ampere.

Yes, our big bore is stroked. After the motor got hot (2 hours xc racing) the thread in the aluminum case at the bottom striped, because the head bold could not reach far enough down into the thread as it was suppose to, and then with the bigger compression of the stroker it just gave way at the weakest spot.

Other than the bolts that stripped we were also very lucky so far - 3 races complete and the everything else is keeping up very well.
Thanks for that info . I wonder why our dealer didnt know that .. but then again, I have to remember who Im referring to . lol :p
We dont have a stroker in ours . We have raced 4- 50 min WORCS races and a couple desert rides with good luck so far . Sometime this summer we will be sending out motor back to the builder to fully inspect to see things are holding up .
We havent had TOO MUCH trouble starting ours, but does have a nice drag. I know at some point it will be a problem so remeding it now is key. Thanks again

quadracer707
03-14-2010, 02:52 PM
Tina,
Am I missing something, or did you say you were getting high 20's in hp, & u still didn't stroke it??

Ken

QuadJunkies
03-14-2010, 08:44 PM
Originally posted by quadracer707
Tina,
Am I missing something, or did you say you were getting high 20's in hp, & u still didn't stroke it??

Ken
Yes, that is correct :)
24.7 as an average ,dual stage filter and a little on the fatter side .
We could get an easy 27-28 leaning it out and going to a K&N filter .

quadracer707
03-15-2010, 06:16 PM
Thats amazing, If iam coorect with out stroking it they figure the 250 is about a max 274cc compared to 300cc, sounds like you got ur $hitt together. We are about 2-3 weeks away from getting our engine together, my son is swamped at his engine builder, & since he is giving me a great deal on doing the engine, they haven't had o time to port & bore anything yet, sucks going to be 60 degrees this week & weekend,


Ken

QuadJunkies
03-15-2010, 06:32 PM
Ken ..check out the dyno runs we done .
The torque is outstanding ! We were happy seeing that more than anything . I posted them in the 250 section.

Hope you get to ride soon ! I know we've got spring fever too . Lol :p

bradley300
03-17-2010, 01:57 PM
mine had 22-24 hp, stock bore and stroke with a custom airbox, 11:1 piston, FCR carb and lots of head work

QuadJunkies
03-17-2010, 02:02 PM
Originally posted by bradley300
mine had 22-24 hp, stock bore and stroke with a custom airbox, 11:1 piston, FCR carb and lots of head work
Bradley,what was your baseline ? That makes a difference and of course,every Dyno is different . We dont read so much into Dyno and HP ,my boys got enough to keep him busy for awhile . ;)
Were more pleased on the toque specs, suspension, traction and tire set up