Freestyle Jetting help with a Blowsion 850 kit!!

[kustumk31]

Picked up a rtr shortblock 850. I'm wondering what to run for jetting?

I have dual 44's
Blowsion 850 kit
B pipe mod
H2o waterbox
Msd cdi
Ada- superbore 175 psi
Lightened flywheel

Nothing special and picked this up for a deal.

Just wondering what I should start at?

Thanks, any help is appreciated!

Keith

 

[Blue]

On my 850 i ran dual 46 with the following specs.
2.3 needle and seat
110 main
120 pilot
It was pretty much dead on.

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[kustumk31]

Would reverse jetting be a good option for me?

 

[Blue]

I dont typically run it but it worked in this case.

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[Vortex]

On my 850 i ran dual 46 with the following specs.
2.3 needle and seat
110 main
120 pilot
It was pretty much dead on.

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Crazy. I run (iirc) 127.5, 145 in novi 48s on a 727. 2.3 n/s 115 spring. I guess it's apples/oranges

 

[Half flip95]

The oem 46s are going to pull fuel a lot better than 48 novis. I used a similar jetting spec for 46s on two different set-ups. Worked pretty good for freeride

 

[Vortex]

The oem 46s are going to pull fuel a lot better than 48 novis.

I have wondered why that is ever since I got the novis. Sorry to de rail.

After studying over the group k article on carbs, you will see their flow bench results show the oem 46 has a stronger pilot signal and the novi has significantly more main jet signal.

Oem carb plays it safe with the stronger pilot signal which is more fuel overall from the pilot jet. So in theory you are starting off your tune with more fuel on oem46 than you would be with novi48

 

[tntsuperjet]

But his post said he running 44's.
So the jet spec for 46's will be to big of jets.
Been long time since I can stock 44's.
But I would think you be in
110-115 low
1005-110 high
Range
2.0 needle
95 gram

 

[kustumk31]

I was thinking
120 pilot
130 main
2.3 n&s
95g spring

 

[d_moss]

I have that same setup and I tried every jet combo and needle. Never got it to run good. Might have been bad reeds even though they look fine. Got pissed gave blowsion a call and new reeds 46mm carbs and their jetting specs and it runs great. Haven't touched it in a year and it always runs. I wish I knew what the problem was. And good luck with yours post back with your results.

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[Blue]

If your trying to run oem 44s off of a couch it will probably never be right. Hopefully you have aftermarket carbs??

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[kustumk31]

Yes that was my plan..... But I guess my plans are changing?

 

[Blue]

If you buy some 46s the jetting i sent you works good. I also used it on a php 898 with very little adjustments. Good luck.

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[tntsuperjet]

I have that same setup and I tried every jet combo and needle. Never got it to run good. Might have been bad reeds even though they look fine. Got pissed gave blowsion a call and new reeds 46mm carbs and their jetting specs and it runs great. Haven't touched it in a year and it always runs. I wish I knew what the problem was. And good luck with yours post back with your results.

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My first guess would be you had mismatch set of stock 44's. Not all the OEM 44's are the same transition port design.
The vacum signal is much weaker on 46's as 44's and require considerable bigger jets in 46vs the 44's.
If you buy aftermarket silver painted 44 and match it up to one of the black 44's it's not same carb.