Jetting psi pipes

S

Superwiz

New member
I am installing a set of psi quad pipes on my 800 what is a good main jet to use on a regular basis I am at sea level. Thank you for your help
 

there are soooo many variables, thats it`s pretty much imposible for anyone to tell you exactly what jets to run..

Before anyone is going to be able to make a guess, will you post what gas you`ll be running? (pump? premium?, race fuel mix?)..does your gas have ethanol in it??
 
I`m not sure how that setup effects intake, exaust return so to speak etc...

plus, who knows the quality of your gas (premium with ethanol? lame old station lacking decent filters, hence, posible stale gas etc)..

I`d just suggest starting out FAT and work your way down by what the plugs tell you on a good lil run..

be sure to start out fat enough that you dont actually burn it down on the first test run..

try the stock jets to START OUT.....see what the plugs read after a run...also keep in mind the temps during that first run...if it`s fairly warm out considering...thats gonna make a huge difference compared to a run when it`s VERY cold out..

the thing is..it`s scary to suggest actuall jets, considering all the variables..and no one wants to be responsible for suggesting what jets to use and end up having a guy report back that he burnt down...

as far as that goes, even starting out with fat stock jetting, could result in a burn down if you had an air leak at the crank/case area, intake leak, dirty carb/s, alotta moisture in your tank from setting etc.. maybe even a real bad pipe/ to head connection?..

just play it safe at first and work your way down..

jets are ALOT cheaper then pistons, cylinder replating, and posibley even worse damage due to a lean condition...

and again, remember temps WILL play a big role..a good plug reading when running on a 20F day, may read lean on the ragged edge on a minus 10F day...just for example..

if/when you get what looks to be the perfect plug reading..Firgure your safe for about a 10F maybe 15F change in temps either way...much more then that, is questionable at best...

the perfect plug read at 20F, might mean a burn down at -10F on a decent hot run..
 
I run 800 psi's on one of my 800's and it likes 50 pilots, needle in the stock middle position and 147.5 main jets.I am at sea level as well.
 
Superwiz said:
So the specs sheets are wrong they are saying 132 of main jet ?????
Click to expand...

not so much wrong, as outdated...IF running pump gas etc...

todays gas is not the same, back then it had MTBE, and the like..often times these days, it`s ethanol..

either way, running 132`s was on the raged edge...even back then..from what I`ve gathered?...(depending on temps and about a half a dozen other things of course)..if I`m not mistaken, and i may very well be..that spec was for "down to" 10F....colder then that was a no go..i could be wrong, as it`s been a while since I`ve read the spec sheet though..

I honestly dont believe there is any one jet size fits all sleds, even if their of the same year, motor CC, pipes etc....just too many variables..only way to go IMO, is FAT then work your way down....
or risk the dreaded...
 
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Superwiz this is a loaded question, with like Al said many variables I'm sure the spec sheet didn't say anything about raised cylinders or shaved heads.
First fuel you should be running should be determined by you squelch.
Second you didn't say how much you raised your cylinders or shaved your head, are you running stock head gaskets?
Third what temperatures will you be riding in? Here it can go from -20 C to -35 C in a day or two.
If I were to take advice on what to jet for again like Al said 'start fat'
This is just some of the stuff I learned about from being on this site.
Hope this helps
 
Around 8800 rpm, but with mods it might be different. Do you have access to a dyno, then you would know for sure.
 
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