i have a 686 raptor w/ 12.5:1 compression, stage 2 webcam, pro flow filter, no lid lte dual exhaust and stock carbs/ignition. the guy that did all this said that the headers are too narrow and that is why my quad is only making 36 hp!!? i don't believe him and i feel that there has to be something holding all the potential hp back.

What can it be?????

 

stock carbs??? there not jetted or anything like that?? thats more than likly your problem...i think you need to get the head ported and polished and then call carb parts wearhouse 121-663-51099 they are great! never steered me wrong...

 

i had the head ported and polished and they had to take the spacer out of the needle and go a "negative turn" in to get more fuel...

 

Nah the stock carbs cant handle that... i believe they are dual 32mm or 34mm?? they need to be rejetted atleast... Call carb parts wearhouse and they will tell you what you need... they set all the Gncc racers up with there carbs and everything they have been around for a long long time!!

 

They will tell you what you need for your altitude sorry about the spelling.... and the kind of riding you do

 

thanks for the help...its appreciated

 

My raptor has very similar mods, 11:1 comp wiseco piston, stg 1 hot cam, pro flo kit with no lid & LTE duals my stock carbs have been rejeted and i'm running 27.5 pilots, gytr needles on the 4th clip position & 170,175 main jets, and a DYNA fs ignition. what kind of a dyno are you using? rear wheel hp dyno? or crankshaft stlye dyno? the stock HP number of 36 hp is measured off the crank. and my 686 is producing 48.2 hp off the crank, i don't know what the rear wheel HP is though. have you rode a stock one to compare?

 

the 36 hp is at the wheel and i had it dynoed before they tore into the engine and i just had gytr full exhaust and that was it and it was making 34 hp...i took it back and told him something can't be right and he is going to swap the lte's with yoshi to see if that does anything and if not he is going back into the engine...should a 3 angle valve job be done bc he said that is the only thing he didn't do..i am in college right now and won't be home for a couple more weeks so we will see how things pan out. thanks for the help again.

 

P.S. Is 93 octane okay for 12.5:1 compression? or should i be mixing it, because i don't feel like going out and buying race fuel if i dont have to.

 

93 octane fuel is not enough for 12.5:1 compression.A 50/50 mix of 110 and 93 would be much better and safer to run with that compression.I had a 690 that was very close to yours and i used 175-180 mains in it for three years with the stock carbs with very good results.Any builder that thinks the LTE is the limiting factor on your motor should be avoided in my opinion.The LTE has very good flow and they are used on some of the fastest Raptors around.