What jetting should I start out with...??

007redline

007redline

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I have a 2001 Yamaha SRX 700 Heavy Ported cylinders but using them for trail riding done by MrViper with the cold air kit..Just got my heads back so I can use high test gas not race fuel..lol. Just wondering if I should go to 45 Pilots and what jetting I should use to start out...thanks
 

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007redline said:
I have a 2001 Yamaha SRX 700 Heavy Ported cylinders but using them for trail riding done by MrViper with the cold air kit..Just got my heads back so I can use high test gas not race fuel..lol. Just wondering if I should go to 45 Pilots and what jetting I should use to start out...thanks
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I'd go right back to MrViper on that question...no one will know better!
 
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45/150 OR 45/152.5

I run 45/152.5, And clip one notch down on the needle on my ported, piped srx.

Every sled will vary but this is a baseline.


What were done to the heads?
 
Don didn't provide you with a ballpark to play in? Impossible to say for sure as every sled/motor will vary slightly, but.....

I'd guess 45 pilots, needles at position 3 or maybe slot 4 with both washer over(touch richer than at 3), 152.5 mains. Obviously this is dependant on your temps, elevation, and fuel quality.
 
i run 152.5 mains and 42.5 pilots. mine is lake race ported and mega power heads. it screams from mid to top but needs tinkering on the low end.
 
Ryan B said:
Don didn't provide you with a ballpark to play in? Impossible to say for sure as every sled/motor will vary slightly, but.....

I'd guess 45 pilots, needles at position 3 or maybe slot 4 with both washer over(touch richer than at 3), 152.5 mains. Obviously this is dependant on your temps, elevation, and fuel quality.
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It was in my buddy's race sled that Don did for him..we talked to Don about what squish for the heads so I could trail ride it but never discussed jetting
 
Makes sense:) He's always been good about providing a guesstimate that is ususally pretty close. Depending on how hot the porting is you might need more main jet than what's been suggested. Maybe start with 155's and see what the motor wants from there.
 
bufalobob said:
no need to turn it back to stock. that's a very dependable pkg.. should get 12-13 mpg. the air box needs to be be gutted to take full advantage of the porting. that set up w/ vforce 2's, cold air kit & bender silencer is about 158 -160 h.p.. trail safe jetting w/ todays fuel would be 157.5 accross, stock pilots & stock needle ( middle ). i ran 155's but the fuel today is not the same as a few years ago. also, make sure you run the carb vent tubes into the air box & let them hang in front of the carbs. the motor will run more consistant.
bob
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Thats from bufalobob in a previous post...its what I run as well with Q-8s 3rd clip
 
just had mine ported and i went with 150 and 50's for pilots and i cant bring the idle down switching to 55 pilots today mine is just a mild trail port with the boost ports done also
 
just had mine ported and i went with 150 and 50's for pilots and i cant bring the idle down switching to 55 pilots today
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where are your needles @, seems like you might be getting hung up on a lean spot on the needle, 50s seems like alot of pilot for a mild trailport
 
staggs65 said:
where are your needles @, seems like you might be getting hung up on a lean spot on the needle, 50s seems like alot of pilot for a mild trailport
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X2

47.5 pilots were a tad on the rich side for mine, I had to have fuel screws at 1 turn or less, I have gone to 45s for this year, but I also am running Aaens with Q8 needle jets.
You might want to check fuel screw setting as well.[I have the remote adjusters on all my sleds and I highly recommend them if you can still find them...makes it easy]
 
Well on mine im running 148 148 and 151...with a 45 I think pilot... needle on 3rd IF i remember correctly.. wanted to write it down when I was cleanin the carbs but forgot to... and bendersrx told me that the jetting was right on for it... though the sled was tuned by mrviper himself too i think...

sideshowbob... your copy and pasted info from another thread was saying 157 all across for jetting... would I need to bump it up that majorly for a cold air intake?! dont plan on getting one since I need this sled to be as much reliable as possible but a 9 jet size but for a cold air intake kit is a massive one... and seems like most of you are recomending a decently bigger number...
 
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Ride.Race.Live
your best bet is to just do some test runs at 1/4 5/8 and full throttle and read your plugs and piston wash, you have a sled thats already been running so just do some testing to see how everythings doing with your fuel and go from there
 
[/QUOTE] sideshowbob... your copy and pasted info from another thread was saying 157 all across for jetting... would I need to bump it up that majorly for a cold air intake?! dont plan on getting one since I need this sled to be as much reliable as possible but a 9 jet size but for a cold air intake kit is a massive one... and seems like most of you are recomending a decently bigger number...[/QUOTE]

Remember every sled is different as well as riding conditions altitudes ect, there is no easy answer and every sled has to be jetted by reading piston wash, plugs ect. Always start rich and adjust from there in a CONSERVATIVE way.

That 157.5 is for:

-2002 SRX
-ported
-VForce reeds
-Bender Silencer[Aaen pipes in my case]
-Gutted Air Box
-Bender Cold Air Kit
-And **** Carb Float Bowl Vent Tubes inside the Airbox****

When you move the Vent Tubes into the Air box it has a SIGNIFICANT influence on your Jetting!!! ie: from say 150 to 157.5 That is why the Vipers run such big mains compared to the SRXs, as the Vipers are vented to the Air box stock, the SRXs are not. The only time you might want the SRXs carbs vented to the Air Box is if you have a cold air kit.

-I also richened up my Needle Jets to Q-8s with all the above mods
 
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I ran 50's in the summer on grass was told by pat hauck the extra fuel is nice for the launch but i also ran smaller air jets from 1.0 to a .8 They are also the ones that told me to go to a 55 pilot to get idle back. My question is why is the idle high is it the mild porting in the cylinders enough because it is only ported to the stock gasket or is it the boost port in the piston which mine is now a 3/4 square hole
 
i bought the sled already tuned by bendersrx... and the previous plugs in it where nice and brown... and he said the jetting was dead on... he has the same elevation as me... So I could go ahead and say that the jetting is fine in it... he spent alot of time tuning in this sled.. and read up on alot of his posts regarding it... I am comfterble enough to say its more then likely fine... if I ever did anything different to it.. then i would def do some testing and go from there... I was just shocked at the sizes people where running... a cold air intake kit does a big number on jetting...
 
007redline said:
I have a 2001 Yamaha SRX 700 Heavy Ported cylinders but using them for trail riding done by MrViper with the cold air kit..Just got my heads back so I can use high test gas not race fuel..lol. Just wondering if I should go to 45 Pilots and what jetting I should use to start out...thanks
Click to expand...


Nice, curious to see how this works for ya this year. I was considering going to Don for some porting but haven't as of yet. Had some race-logic ported cylinders last year but just couldn't get it dialed in. I'm back to stock now.
 
Ride.Race.Live said:
i bought the sled already tuned by bendersrx... and the previous plugs in it where nice and brown... and he said the jetting was dead on... he has the same elevation as me... So I could go ahead and say that the jetting is fine in it... he spent alot of time tuning in this sled.. and read up on alot of his posts regarding it... I am comfterble enough to say its more then likely fine... if I ever did anything different to it.. then i would def do some testing and go from there... I was just shocked at the sizes people where running... a cold air intake kit does a big number on jetting...
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Sounds like its spot on! Leave well enough alone.
My SRX has to be able to run wide open for very long lake crossings and survive at up to -30c so I am always jetted on the safe side. If I was not venting to the airbox with a cold air kit I would likely be around 150 mains.
 
I do alot of lake runs at WOT. too... and around the same temps... but I checked my plugs at a warmer temp after riding around 0c to -5c.. and they where not brown... they where blackish... though normal riding temps later in the year will be around -15c or more colder..

but i was able to tell she was running "fat" compared to the first time i took it out at -17c...
 
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