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ok. i have to jet mine after the 3'' snork i jus did so i guess i should go ahead and do this b4 i start so i dont have to deal with the head aches of the jets
 
Discussion starter · #23 ·
I see in your signiture that you have the BF 750...is this the bike you will do the mod on? I thought I read somewhere that this mod will only work on Prairies, sra and vforce but I will try and find out for sure and post back here.

If I confirm this I will make a note of it in the original post so there is no confusion.
 
ok do that if u will
 
Discussion starter · #25 ·
Ok sorry for the confusion byrd......apparently the crossover mod will only work on Prairie 650/700, vforce and BF 650 sra models.

The 650i and 750 are supposed to have different intake runners and heads so the mod will NOT work on these models wether they are FI or carby.

I will edit the first post to include this information so there is no confusion....sorry.
 
Discussion starter · #26 ·
Here is a quote from VFORCEJOHN on jetting for crossover intake.

"jetting will be lower than normal if you are using stock closed airbox even if piped CDI I use 145-150. with the crossover you can run stock jetting but need a 42 pilot.

open airbox. you will need 200+ main jets. so you have to drill them to 5/64's and te 42 pilot as well

but you make more power using closed airbox on the stock intermal setup on the prairie or bf 650."
 
Discussion starter · #27 ·
Another quote from VFORCEJOHN regarding HP gains with crossover intakes.

"They actually gain more HP on a stock bike. I've seen +6 rwhp +8 rwhp on a stock internal machine.

Vforce I got to 50 rwhp
Prairie Twinpeaks 700 to 47 rwhp

They are an all over gain. top end gains are even better than the peak gains

On modded motors Like 730's I see 2-3 rwhp gain with the 32 crossovers."
 
well that blows. ill do a different mod then. maybe make me a custom dual exhaust
 
hey kawboy, where did you get your fuel pump? the want 66$ for a 42s where i am, that seems like a lot for a tiny electric pump.
 
Discussion starter · #33 ·
I just got mine from an auto parts store down here.....think it was like 70 bucks.

It does not have to be the 42s as long as it is low presure up to 3.5 maybe 4 psi. Hey I noticed in another thread you said you removed your KEBC fork....did you leave your bearing in the primary cover that the fork use to run on?

I removed my fork today and was wanting to make sure that it was safe to leave that bearing there with no presure on it......just hope it cant fall out and mess something up.
 
ya, i left my bearing in. so far so good! did you notice any improvment after polishing your slides? and what about the cut springs?
 
Discussion starter · #36 · (Edited)
Ok as of today the xovers are off.......the **** electric fuel pump sh*# it self......just glad it happened in the yard and not when I was out ride'n the other day!

Until I can find a better quality pump they will stay off.....now it will always be in the back of my mind even if I do find a better pump.....I loved the extra power but I need reliability more.

UPDATE: now useing the mr gasket 42s fuel pump for a couple of months without any probs.
 
how do you get the intake boots at the correct spacing? i havent looked at stock stuff but im guessing they are not connected as stock. thanks also does a 2005 bf650sra have aelectric fuels pump. and why wouldnt peple use kawi pumps in exchange for off the shelf models? thank
 
Discussion starter · #38 ·
Correct....they are not conected stk. Not sure what year kawie swithed to the vac pumps but I think the Prairies had the electric.....or at least some. I think people dont use kawie pumps because they are in tank pumps wich means that you would also possibly need the tank? Plus price? If you use the mr gasket 42s pump you should not have any probs.

You need to have the stk intakes bolted to the motor, cut a piece of pipe roughly to length, hold it down by the intakes and figure where it needs to go......then mark it on the intakes......always double check everything before cutting/making holes ect.
 
Here is a quote from VFORCEJOHN on jetting for crossover intake.

"jetting will be lower than normal if you are using stock closed airbox even if piped CDI I use 145-150. with the crossover you can run stock jetting but need a 42 pilot.

open airbox. you will need 200+ main jets. so you have to drill them to 5/64's and te 42 pilot as well

but you make more power using closed airbox on the stock intermal setup on the prairie or bf 650."

So, let me make sure that I understand this correctly.
If I do this mod to my 2008 650 SRA, I would have to rejet my carbs and go to a 42 pilot jet, correct?

My current set-up is Dynatec CDI, Full Muzzy exhaust, Jetted 148F - 155R with both needles shimmed .040, K&N air filter wtih prefilter and 2" Snorkel.
 
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