B.C Jetting for REV 800's

[Shibby!]

What have you guys done to your jetting for compensate for our elevations?

I know for a fact mine's running stinking rich, as do most sleds. A 2-stroke isn't a 2-stoke until it's jetted right. I love the crisp, quick reacting 2-stroke when it's properly jetted. I'd like to play around with mine and figured I'd start by changing clip position, and possibly swapping the idle jet.

I'm used to jetting bikes, but not sleds. Same theory, but the needles and jets are all different. Curious if others have a good baseline to go off of?

Model year is a 2006 800.

Thanks,
Q

 

[maxwell]

what machine? what mods? if its a summit it should deffinetly have DPM and not need to be jetted. most people with stock machines can only vary 1-2 sizes leaner.

 

[Shibby!]

what machine? what mods? if its a summit it should deffinetly have DPM and not need to be jetted. most people with stock machines can only vary 1-2 sizes leaner.

Sorry for incomplete info. I was under the impression it was in my signature.

It's a 2006 Summit 800. Stock, only an aftermarket silencer added.

As for people who think the DPM modulates jetting accurately to elevation, you believe the marketing that BRP sells.

The jetting may change, but the jetting is nowhere near correct from the factory.

To me it's amazing how many people don't change their jetting and think it's good from the factory. The reason I feel this is done is because it actually takes work. Motorcycle jetting is changed on almost every bike because it either requires it, or it's easier to adjust.

So for those people who don't fall for marketing and take things into their own hands, what did you do? How does it feel, where was the improvement, and what do you plan for future test rides?

Please don't take me wrong. I'm not trying to be an ass but I probably come across that way.

 

[boots]

Sorry for incomplete info. I was under the impression it was in my signature.

It's a 2006 Summit 800. Stock, only an aftermarket silencer added.

As for people who think the DPM modulates jetting accurately to elevation, you believe the marketing that BRP sells.

The jetting may change, but the jetting is nowhere near correct from the factory.

To me it's amazing how many people don't change their jetting and think it's good from the factory. The reason I feel this is done is because it actually takes work. Motorcycle jetting is changed on almost every bike because it either requires it, or it's easier to adjust.

So for those people who don't fall for marketing and take things into their own hands, what did you do? How does it feel, where was the improvement, and what do you plan for future test rides?

Please don't take me wrong. I'm not trying to be an ass but I probably come across that way.

sorry cant help

 

[maxwell]

im hearing what your saying but its not completely true.

no the dpm does not directly adjust the jetting. it controls the pressure to the float bowls based on temperature and elevation. and it DOES work. you need to set a good baseline for the dpm to either adjust + or - from your base.

every machine is differant and every owner has a differant comfort level of how safe they want there jetting to be.

heres what i have found with the many 800pteks i have dealt with.

main jet is a 440. in stock form you can vary from this down to a 420and maybe after riding it and checking your plugs and piston wash you may be able to move to a 410. with an aftermarket head with better cooling capabilities and a more efficient combustion like an rkt and a terra alps you may be able to move it down to a 400/390. DEPENDS.

i wouldnt vary more than one size at a time without doing those basic tests. why burn it down for a sled that works just fine from the factory with the 440 jet. when ever you start adding bolt ons like reeds/pipe/can you may have to run the 440 jets but it will clean up with the increased flow.

if your sled isnt crisp and quick reacting maybe you should be looking at another area of concern.

 

[Summiteer]

My plugs are a nice rich brown. I'll stick to the factory jetting thanks.

 

[maxwell]

yeah ive never ran into one that wasnt close to band on. or varied enough to bother to change it for any gains.

 

[Shibby!]

im hearing what your saying but its not completely true.

no the dpm does not directly adjust the jetting. it controls the pressure to the float bowls based on temperature and elevation. and it DOES work. you need to set a good baseline for the dpm to either adjust + or - from your base.

every machine is differant and every owner has a differant comfort level of how safe they want there jetting to be.

heres what i have found with the many 800pteks i have dealt with.

main jet is a 440. in stock form you can vary from this down to a 420and maybe after riding it and checking your plugs and piston wash you may be able to move to a 410. with an aftermarket head with better cooling capabilities and a more efficient combustion like an rkt and a terra alps you may be able to move it down to a 400/390. DEPENDS.

i wouldnt vary more than one size at a time without doing those basic tests. why burn it down for a sled that works just fine from the factory with the 440 jet. when ever you start adding bolt ons like reeds/pipe/can you may have to run the 440 jets but it will clean up with the increased flow.

if your sled isnt crisp and quick reacting maybe you should be looking at another area of concern.

Well that's what I was hoping to hear. I understand the system does compensate, however it only adjusts what's already there to a preset measurement using other variables. What I know is with my sled it's not a very good baseline. The plugs aren't within range, and IMO, this isn't a good test alone. Most sleds that I have seen pulled plugs are running rich.

I know better to not jump with big increments, but I will lean it out a bit and see it's affects. I'm not a WOT kind of rider. I feel no need to. I can climb and do as much as most of my riding buddies using 1/2 or less throttle. I do use short stints of WOT, but only when required. I ride everything I own like this and it hasn't slowed me down. That being said I'm not a great sledder by any means. It's more about the feel and response I'm after.

 

[maxwell]

well if thats the case you might want to look at adjusting your needle setting.

main jet only comes into play after about 3/4 throttle. other than that the needle is regulating the flow coming from the mainjet.

 

[Shibby!]

well if thats the case you might want to look at adjusting your needle setting.

main jet only comes into play after about 3/4 throttle. other than that the needle is regulating the flow coming from the mainjet.

Yup..

Actually I'm mostly wanting to change my slow jet and needle. Not sure if these needles have clips positions? I'll have to look at the slow/idle jet to see what I'll have to go to.

 

[krazy ken]

I know on the 04 800 the stock jet was 400 and was told by Jerry at Martins to drop to a 380, which I did. Much better plug condition and crisper response. Now that I've done a wack of mods have to check plugs all the time to see what's happen. Don't know if Doo changed settings or carbs in 06 but thats what I did. Just my 2 cents.

 

[Modman]

Almost all sleds from the factory are jetted rich (reliability). I have always dropped 2-3 mains and at least one needle position and one tube size from factory in every sled I have owned. The closest one out of the dealership I saw last year was an XP that had been dropped one main size, plugs were a perfect colour, nice light tan. Other than that, they're almost all rich. But sometimes its better to be safe than sorry too. Everyone has their own preference, I'm like Shibby, I'll drop it until it to improve a little bit, some guys are more preferenced to just ride it and leave it alone, it runs good enough for them.

 

[Shibby!]

Almost all sleds from the factory are jetted rich (reliability). I have always dropped 2-3 mains and at least one needle position and one tube size from factory in every sled I have owned. The closest one out of the dealership I saw last year was an XP that had been dropped one main size, plugs were a perfect colour, nice light tan. Other than that, they're almost all rich. But sometimes its better to be safe than sorry too. Everyone has their own preference, I'm like Shibby, I'll drop it until it to improve a little bit, some guys are more preferenced to just ride it and leave it alone, it runs good enough for them.

Yea, I've found those XP's come a lot better tuned from the factory. Also the 800R is such a smooth motor, even though they have tendancies to blow up.

I'm not looking to push my limits, I do want to have small room for error, but like Modman said, there can still be room for error and have something that works a lot better.

I'm trying to get out to the garage one of these nights to take a look at whats requried to change jettings. I've left it for so long becuase they aren't easy to work on. At the same time i'll do a leak down test to confirm the motor is in good running condition so I can be confident in my jetting modifications.

 

[maxwell]

the ptek in 06 comes with 440 jet not 400.

 

[Shibby!]

the ptek in 06 comes with 440 jet not 400.

Thanks Maxwell.

I'll probably take the carb apart and make sure all is clean and good inside. My worry also is that my carb boots are delaminated and leaking so I'll do a pressure test. I imagine my Y-pipe is cracked as well.

Would like to get these issues fixed before riding season. The snow is coming down in Calgary right now!!

 

[maxwell]

yeah cracked carb boots and ypipe are not good for the tuning of the motor.

if you do need new carb boots order a set of vforce or boysen reeds. thhey are 300$ and come with new boots. while just the stock brp boots are 300. so its worth it.

 

[Shibby!]

yeah cracked carb boots and ypipe are not good for the tuning of the motor.

if you do need new carb boots order a set of vforce or boysen reeds. thhey are 300$ and come with new boots. while just the stock brp boots are 300. so its worth it.

Are they as durable as stock though? I've ran both Boyseen and Vforce on my dirt bikes and have handled it very well, however on the sled I've heard complaints about the pedals chipping, etc. Then again the stock boots delaminate after a year or two of use..

I'd probably go aftermarket. Pedals are cheaper then new boots IIRC.

 

[mel.h]

I have had the V-Force Reeds on for quite awhile & no problems so far, worth the upgrade IMO.

 

[sheebansavage]

FWIW... My 05 800, I dropped the mains from 400 to 390 with no issues.

Cheers