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XP big bores - lets compare

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Insaneboltrounder/sjohns

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Nov 26, 2007
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The guy who seems to know almost nothing about engine mods or any basic " how to" but is an expert because he has one that he knows really nothing about? That guy?? sj
 
G
Apr 23, 2008
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Jake,,
Yes the same person.

Another O.T.
what I don't get is he wasn't even involved,, not a posting ,,

It sours me out that someone would do that without explanation..


Gus:mad:
 
M

MontanaPowder

Active member
Nov 30, 2007
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Kalispell
Gus- your 100% correct for TWIN PIPES:beer;(FYI- those HP #'s are from twin pipes/ 16.5-1 head @ straight 110 octane / snoX mod ignition box)...a single pipe is whole different game, like 207-208 ex port heights ;)....

I just did a twin pipe specific 860...when bored out the ex port dropped 3 degree (202 vs stock 205)...we left it there, BUT still ported everything else, just didnt RAISE the ex. port timing...per Crank Shop specs to match there TWIN pipes...

HENCE the issue with any BB with no porting...intake/transfers OK...BUT the ex port is lower @ smaller + stock sub ports = no HP gains....BJ

BJ, I am running the Jaws twins at end of this season on 860. I had some difficulties tied to my ecm. I had it previously set by BRP it just never ran as good as stock ecm. I took stock ecm with me to the mtns and walla, picked up 800 rpm. I have recently received stock timing settings along with removal of knock, set limiter to 9000 and removed overtemp retard.

Looking forward to more testing next year. With stock timing curves it was a beast, I had a full race gas TD8 to compare with. I am not a engine builder but after riding for 30 years in mountains with many mod sleds I know when one works. I understand you leave your ecm stock IMO a good idea related to all the timing maps.

Kelsey was very kind to give me a 12.5 set of heads vs the 14:1 I had with kit. I don't know now that I found the ecm issue if I should go back to the 14:1 heads as it ran great at 7000 feet. Buddy indicated Jaws twins tend to run better with more squish, I don't know.??

Please keep us updated on the results of the twin cranks. I have had good success with two sets of cranks on POL mod motors by Union Bay.

Thanks
Mike
 

Dbook

Well-known member
Premium Member
Nov 26, 2007
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Denver, Colorado
crffred !!!!
I see you flamed me on my reputation..

You did not like my comment above on port times and the results ??
If you have an issue with me put it out for us all to see and understand..


I eagerly await a public explanation of your reasoning..

Pay attention BJ,, this guy is trouble..


Gus

Same dude gave me red rep in a thread about summer XP mod's. I was harassing a buddy and he rep repped me for it! LOL, the guy is a dink.
 
G
Apr 23, 2008
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Yep,, dog is dead, just called the man out on his opinion...

Don't agree with me, thats fine, give me a bad rep but have the humanity to give a reason why ??:mad:

the word bull**** is meaningless,,


oh well back to our regularly scheduled program...LOL:D


BRP had some issues with programming variation even at the race level, smome boxs just were NOT doing what they were theoretically programed for.


Gus:beer;
 
I

Insaneboltrounder/sjohns

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Nov 26, 2007
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who reads rep... other than dikks like him. Look at the crowd fav in here , OT , he is redder than red and he still thinks ppl GAF what he says. Sure is nice in here without that loud mouth.
 

BIG JOHN

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Premium Member
Nov 26, 2007
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Minnesoooota
BJ, I am running the Jaws twins at end of this season on 860. I had some difficulties tied to my ecm. I had it previously set by BRP it just never ran as good as stock ecm. I took stock ecm with me to the mtns and walla, picked up 800 rpm. I have recently received stock timing settings along with removal of knock, set limiter to 9000 and removed overtemp retard.

Looking forward to more testing next year. With stock timing curves it was a beast, I had a full race gas TD8 to compare with. I am not a engine builder but after riding for 30 years in mountains with many mod sleds I know when one works. I understand you leave your ecm stock IMO a good idea related to all the timing maps.

Kelsey was very kind to give me a 12.5 set of heads vs the 14:1 I had with kit. I don't know now that I found the ecm issue if I should go back to the 14:1 heads as it ran great at 7000 feet. Buddy indicated Jaws twins tend to run better with more squish, I don't know.??

Please keep us updated on the results of the twin cranks. I have had good success with two sets of cranks on POL mod motors by Union Bay.

Thanks
Mike


In my travels...the race dept. had a hard time with MPEM reprogramming...much less EPA spec ECM's....so I leave the box alone or just bump timing 1 degree (dealer)...as for the twin pipe motor, its up and running..will dyno soon...BJ
 
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Insaneboltrounder/sjohns

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Nov 26, 2007
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Thought this would be fitting background music as you read gus, sj, and dbook's post's. Get over it!


http://www.youtube.com/watch?v=mGKH0BK5VaA

Didnt play it... im sure its right up there with your jonas bros cd there sparky. Get back to us on that plug indexing idea you came up with. Im sure OT will be happy to know you filled in for him while he is prob being an azz on a atv site for the summer. sj
 
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Leaf27

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Premium Member
Oct 24, 2008
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well we know yours works good! hey fred!:beer; by the way! im getting my new sled tunneled right now!

Cheers Bud, I am going to K-town for H-days will stop in and check it out, I am sure it will kick azz.

Hopefully the tears and whinning about red rep have stopped so the quality discussion about 860BB can continue. Not sure why your trollng around this thread trying to get an argument started SJ, seems kind of pointless to me.:confused: No replay necessary.:beer;
 
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RKT

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Jul 19, 2001
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Preston, Idaho
www.2strokeheads.com
Back on Topic..

Trying to get this thread back on topic...

The 860BB will not disappoint (when done right). It is really an over-chiever.
I have offered MANY fellow riders and forum members to ride my sleds and quite a few have taking me up on that offer. The 860R will impress ANY rider. That is my honest opinion

If you feel your XP Big Bore is not up to "par" please contact me and I can see what I can do to get it where it needs to be..

I will be offering HUGE discounts on "fixing" ANY big bore (not done by RK Tek or SHR).

If anybody else is in DaveB's situation (hopefully, there are not many). We will to our best to get it running to its potential at the absolute minimum cost..

Kelsey
 
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I

Insaneboltrounder/sjohns

Well-known member
Nov 26, 2007
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Cheers Bud, I am going to K-town for H-days will stop in and check it out, I am sure it will kick azz.

Hopefully the tears and whinning about red rep have stopped so the quality discussion about 860BB can continue. Not sure why your trollng around this thread trying to get an argument started SJ, seems kind of pointless to me.:confused: No replay necessary.:beer;

You started it :face-icon-small-con
 

Dynamo^Joe

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Nov 26, 2007
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www.iBackshift.com
has anyone run a mots 880? i would like to deal with someone local and im 5 minutes from them.

This past season, I have two clutch kit customers who ran Tom Mots BB engines in xp 163's. Both guys made the trip to the dyno, revealing 169hp.

The one guy Chris's engine, does it sound correct if he had 109 lbs torque at 8100 rpms w/slp pipe?

To me that ain't too shabby as at 6500 (Revystoke) played around with my QR11 clutch kit and some different sets of ramps - not wanting to change the primary spring, just wanting to see what fun could have with different ramps.
With a 413 or 415 punching off the line the engine would whack the rev limiter for about 2~3 seconds then start to clutch shift, the engine pull down rpms and stand the sled right up on it's tail.

Played with other ramps, 414, 441 and another mod set of ramps I ground up, seemed any aggressive ramp other than a 413, 415 worked pretty good.

I just look at what primary calibration he had before with stock engine that the 413, 415 would come off the line pretty good rpms 8100~8200 and haul. Then after the big bore there was definetely some torque being made off the line - revealed by evidence of engine rpms hitting the rev limter for slight moments under full throttle.

In the final analysis (not wanting to change the primary spring) IF the clutch calibration was not changed, however engine power was changed; THEN the engine hitting the rev limiter is an indication that the engine could build torque quick enough to overcome the previous engine calibration.

Chris used a full 2.5 grams more (18g) with Mots BB mod vs a stock 09/800xp (15.5g) w/QR11 clutch kit

Ok then, heavy up the ramp angle and make the sucker pull......
.
.
.
....and it did my friend! :devil:

--------------------------------
It was beneficial to dyno before and after the BB.
 
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