gas

[murrays400ex]

i know this has been asked a million times but can i run 93 when i have 440 kit with 11:1 compression and a hot cam 1 but i need a real reasson my dad doesnt by the detonation timing deal so i thought if a more pro person could help.........if i dont get a good answer ill have 2 run 87 and blow up my quad.....shat

[rwhitaker04]

well ur supposed to run 93 with a stock bore...so i think 93 would work on a bore...but with a 440 kit..ur gonna go threw valve seals every few races...should have went 416 or 426

[rwhitaker04]

y did u run a stage 1 cam with a bore kit? stage 1's are for stock bore engines..should have went stage 2 u'd have more power..out of your 440..its almost like wasting your bore with stage 1 cam..

[jak1389]

reconmended bu hotcams, the stage 1 is only usable until a 426 bore. its not reconmended for anything above that. so im not so sure i would run that cam.

[rooster_20]

not meanin to take over the post or anything but if you run 87 octane in your ex with stock bore would that mess it up? I have the mods in my sig thanks for the help

[rwhitaker04]

well i feel u should run 93 octane n stock bore 400ex and 100 octane in bored applications...but thats just me..

[400exrider707]

Originally posted by rwhitaker04
well i feel u should run 93 octane n stock bore 400ex and 100 octane in bored applications...but thats just me..

I disagree with just about everything you have posted so far.

First off I have run 87 in my 400ex for its whole life without any problems. I know run an 11:1 piston stock bore with a stage 1 hotcam and only run 93 octane. I wouldn't even consider running 100 octane until I jump to at least 12:1 compression. Also what reasoning do you have for saying hes going to blow valve seals all the time?!?!:huh If it is built right it could be made to be just as reliable as stock. Also the stage 1 would be a good idea if your only running 11:1 compression. I guess it all comes down to what type of riding your doing but I would say the stage 1 is going to be a good all around choice. Once you went to say a 12:1 piston then maybe take a look at the stage 2 cam.

So to help you guys out Rosster_20 you can run 87 just as long as your engine is detonating. Mine never did and I haven't heard of anyone elses either. Murrays400ex you will be more than fine running 93 on an 11:1 piston. If I was you I would say go with your original choice of the stage 1 and then if it doesn't meet your needs then try a stage 2. Rwhitaker04, you dont choose what octane gas you run by your bore size. That has NOTHING to do with it. You pick what gas you run by what compression you are running. Anything up to 11:1 you will be fine with 93 (especially on wiseco pistons in a 400ex) 12.5:1 and up race gas only. Now some say you can mix 50/50 with pump and race gas for 12:1 and 12.5:1 applications, but Im not a fan of mixing so I would try and find maybe some 100 or 98 octane. That should do the trick.

[rwhitaker04]

hmm thats funny...that all places i call around to with just a 416 bore they say use a stage 2 cam..with what a 10.5 to 1 piston..
if u read your owners manual..and every other magizine that test 4wheelers u would also see that u run 93 octane..in them...and ive talked to people who are in the top 5 in gncc points who blew valve seals alot..due to the fact of it getting hot..theres no real way to cool and air cooled engine down when u do motor work that envolves making more friction...and boys and girls..what does fricition do...IT GETS HOT...and this is also running bigger oil cooler and pingry tank...and for a stage 1 cam..if u read what hot cams tells you STAGE 1 stock or mild engine work...Stage 2 mild to whatever u want to call it..extreme..i guess..engine work...and murray if i were u...check around with that all the other 440s have in them...im sure u wont find to many if any with a stage 1 cam in it...but hell i may be wrong..u prolly wont find to many 416 426's with stage 1's..oo..and 400ex ive also talked to Colby at C & D racing...and he told me to use stage 2 in my 416 bore...but hell he may not know what hes talkin bout either???

[trxkid]

93 octane should be fine

Not to hijack the thread or anything but i didnt wanna start one over this..

At my local shop he has leaded race gas for $6 a gallon hes liek that will give ur 400 great throttle response should i pick up a couple gallons for when i go to the track? any expiriences with it?

only two strokes benifit from leaded gas, and if its a high octane and your bike is stick you will actualy loose power

[400exrider707]

Originally posted by rwhitaker04
hmm thats funny...that all places i call around to with just a 416 bore they say use a stage 2 cam..with what a 10.5 to 1 piston..
if u read your owners manual..and every other magizine that test 4wheelers u would also see that u run 93 octane..in them...and ive talked to people who are in the top 5 in gncc points who blew valve seals alot..due to the fact of it getting hot..theres no real way to cool and air cooled engine down when u do motor work that envolves making more friction...and boys and girls..what does fricition do...IT GETS HOT...and this is also running bigger oil cooler and pingry tank...and for a stage 1 cam..if u read what hot cams tells you STAGE 1 stock or mild engine work...Stage 2 mild to whatever u want to call it..extreme..i guess..engine work...and murray if i were u...check around with that all the other 440s have in them...im sure u wont find to many if any with a stage 1 cam in it...but hell i may be wrong..u prolly wont find to many 416 426's with stage 1's..oo..and 400ex ive also talked to Colby at C & D racing...and he told me to use stage 2 in my 416 bore...but hell he may not know what hes talkin bout either???

Thats fine if you want to pay the extra for 93 pump on a stock machine then be my guest. Running too high of an octane will actually make it harder to start. All I said was that I ran 87 in mine for over a year and had NO problems what so ever. No one can tell you what cam you need. Its going to be based on what type of riding you do. If hes doing strictly trails then what good would a stage 2 do for him since they actually lose bottom end power!? (old stage 2 btw not the new one) That is why I told him try the stage 1 and see how he feels, he can always sell it and buy a stage 2. Did your gncc buddies tell you to run 100 octane on bored engines as well? Because boring does nothing as far as timing and or compression ratios, so there would be no need for increase in octane, unless you went with a higher compression piston. You can stick with 93 up to 11:1 and I've talked to people on this site who use 93 on their 12:1 applications. Although its not something I would do personally. Im not going to say a thing about what colby told you because Im sure he asked what type of riding your doing and qualified you, THEN made a decision as to what cam would be best for you. And I dont care who you talked to if you build your 440 correctly you wont be "going through valve seals every few races" because then NO ONE would be running a 440 kit.......

[rwhitaker04]

do u even know what the octane means? its how much it needs to combust..87 being the easiest to combust...and tell me this y do cars run generally better on 93 octane then 87octane? and if he rides trails then y would he get a 440 kit? u got alot of what ifs and ??? that make no sense...who cares what he rides...a stage 1 cam w/ a 440 kit is gonna cancel each other out...but u can think about whatever u need...it sounds like a waste to me...and yes if your racing...im pretty sure it gets pretty hot..and maybe it wont be every few races..but im sure...it will burn in the long run..when a 416 kit or a tc 426 kit is more then enough to compete on either circuits of racing..

[rwhitaker04]

and no they didnt tell me to run 100 octane..ive seen full mx quads run 10x better on 100 octane thats y i suggested it...

[prepracing]

Originally posted by rwhitaker04
hmm thats funny...that all places i call around to with just a 416 bore they say use a stage 2 cam..with what a 10.5 to 1 piston..
if u read your owners manual..and every other magizine that test 4wheelers u would also see that u run 93 octane..in them...and ive talked to people who are in the top 5 in gncc points who blew valve seals alot..due to the fact of it getting hot..theres no real way to cool and air cooled engine down when u do motor work that envolves making more friction...and boys and girls..what does fricition do...IT GETS HOT...and this is also running bigger oil cooler and pingry tank...and for a stage 1 cam..if u read what hot cams tells you STAGE 1 stock or mild engine work...Stage 2 mild to whatever u want to call it..extreme..i guess..engine work...and murray if i were u...check around with that all the other 440s have in them...im sure u wont find to many if any with a stage 1 cam in it...but hell i may be wrong..u prolly wont find to many 416 426's with stage 1's..oo..and 400ex ive also talked to Colby at C & D racing...and he told me to use stage 2 in my 416 bore...but hell he may not know what hes talkin bout either???
so top five in GNCC points are engine experts :confused: what top 5 are they in....... if its other than pro class, their guess would be no better than anybody elses.... thats right GUESS !

[400exrider707]

Originally posted by rwhitaker04
do u even know what the octane means? its how much it needs to combust..87 being the easiest to combust...and tell me this y do cars run generally better on 93 octane then 87octane? and if he rides trails then y would he get a 440 kit? u got alot of what ifs and ??? that make no sense...who cares what he rides...a stage 1 cam w/ a 440 kit is gonna cancel each other out...but u can think about whatever u need...it sounds like a waste to me...and yes if your racing...im pretty sure it gets pretty hot..and maybe it wont be every few races..but im sure...it will burn in the long run..when a 416 kit or a tc 426 kit is more then enough to compete on either circuits of racing..

What exactly is your point about octane ratings? I said it is harder to start with a higher octane, meaning that the higher the octane number the higher temperature it needs to combust, so you just proved my point, but whatever. Who says all cars will run better on 93? Also how exactly will a stage 1 cam and a 440 piston cancel each other out? Please explain that one. What exactly are you talking about when you say "burn in the long run"??? I really dont understand what your saying here!?

[sportraxkid]

I have had my 11.1 wiseco 440 piston with hotcam stage 2 in for about a year and have ran it on nothing but 91 octane which is the highest pump gas in Utah and have never had a single problem with it.I have never touched the valves and it has atleast a 1000 miles on the 440 kit. And when it was stock I ran 87 and never had a problem with it and Ive rode the crap out of it.Also my friend has the same setup as me and runs the same gas and has had it for 3 years and has only blown 1 head gasket. He ran 100 octane in it 1 time and it ran the same!