more carb Q's 05 450R

[gearhead400]

GRRRRR!!! i have a race this weekend and i can't figure this damn thing out. The bike i have had an LRD full system on it, with no airbox lid and a k&N filter. I rode it at croom for 3/4 of the day, rode to the main pit (15minutes) rod in the pit without much longer than 5-10 minutes rest for about 20 minutes, and half way back, the bike started firing off (backfiring out of the exhaust) and cutting out, and everytime it would cut out, my overheat light would come on. I figured the jetting was off and it was overheating because it was too lean, so i just bought a jet kit to put it back to an all stock bike.

i bought a stock filter for it, but i dont have the aluminum insert to attach it to the box, so the k&n is on there with the lid. The bike also has a revmax box and i dont have the stock CDI.

I have no idea what size my pilot jet is, the guy i bought the quad from, i cant get ahold of. The jet kit i bought at OAS at croom (dynojet, which i found out is junk) doesnt have stock jet sizes. The 450r calls for a 118 main and a 48 pilot, with the third clip from the top, fuel screw at 1.75 turns out.

Well i put in a 120 main since i didnt have a 118 and figured a little tuning would get it to where it needed to be. I put the fuel screw at 1.75 turns out, kept the unknown pilot in, and put the clip second to the top. It started and would run with the choke, but it would cut out a lot. I was told that this ment it was lean, considering if i didnt use the choke, and tried to pull it above an idle (no load) it would die.

So, i figured if i moved that needle to the 3rd clip, it would allow a little more fuel, and should be top notch....right? wrong, i start it up, after a lot of HARD kicks, and it starts reving sky high, though not smooth, it kinda jumped around. SOO no thinking it could possibly be that small clip change, i turn the fuel screw to 1.25 turns out, which i realise is an extreme adjustment, and the first time i kicked it over, it fired out of the exhaust (commonly refered to as a backfire) so im **#&*#& pissed off right now. can anyone lend me some quick advice so i dont miss my first race of the season?

If you have aol/aim i'll be logged on
S/n gearhead 426ex
If im not online, it will go right to my phone so you can still message me.

thanks for any help!

[gearhead400]

Also, i dont feel like messing up this bike before i even race it, so im going to wait for some responses. BUT to turn the fuel screw, i just rotated the carb to get to the screw. I didn't drain the bowl, could that have something to do with the high reving? 

[trx#9]

If you have a k&n with no filter lid on you should have at least a 180 main jet. Put the needle in the middle position. It's amazing how much the jetting changes with no filter lid on.

[gearhead400]

thats exactly where it was at with the full exhaust. The header is obviously bigger than stock, should i still be ok?

[TRX450R_Racer]

With no lid, a pipe & the K&N, you should have a
185-190 main
The clip on the needle 1 notch down from the center, which raises the neddle a little
a 50 pilot which is one size up from stock.
I forget where my idle air screw is.

I hate those aftermarket CDIs I will be there with my quad but not racing. I have jets and a uni foam filter you can borrow. If you can get to the track on Friday I will help you make it right. If need be you can use my stock CDI for the race and then pick on up off ebay or something.

Yes dynojets suck

[gearhead400]

almost forgot, i switched out exhaust with the lid off and same filter, and it cut out mid throttle (needle correct?)

I'm eventually going to go back to stock filter and box because i race xc which is a ton of dust and mud and water is always a possiblity (if you have seen any of the gncc races this year, its a definite haha) but for this race i guess i'll be running stock exhaust, lid (missing the o-ring, freakin dealer nickle and diming)  and k&n...im so frustrated  

[TRX450R_Racer]

you have no air box?

I have an extra one you can have for free.

[TRX450R_Racer]

When is the last time the valves were adjusted?

[gearhead400]

With no lid, a pipe & the K&N, you should have a
185-190 main
The clip on the needle 1 notch down from the center, which raises the neddle a little
a 50 pilot which is one size up from stock.
I forget where my idle air screw is.

I hate those aftermarket CDIs I will be there with my quad but not racing. I have jets and a uni foam filter you can borrow. If you can get to the track on Friday I will help you make it right. If need be you can use my stock CDI for the race and then pick on up off ebay or something.

Yes dynojets suck

thanks man! im going to try and get it right before then, but i really really appreciate you lending a hand!  I'll go to honda tomorrow and see if i cant order the right size pilot jet and get it here on time. I want to junk the aftermarket cdi too, but i thought new tires would be a better investment since i basically had slicks.

But stock everything, it should be 118 main, 48 pilot, 3rd notch right? just so im prepared, so i can make the switch before the second race.

no i have a box and a lid, they just didnt sent the o-ring that makes it fit flush. guess thats another $15  

couldnt tell you when the valves where adjusted. I havent gotten a shim kit for it yet either.

[trx#9]

thats exactly where it was at with the full exhaust. The header is obviously bigger than stock, should i still be ok?

Your taking the LRD exhaust off? Your fuel screw should be 2 and 1/2 turn out. The right way to adjust it is to have the quad running put it in gear, the idle should drop down and then you can turn the fuel screw back and forth. What your looking for is the idle to slightly raise up and when that happen it is the sweet spot for maximum performance. I would start it around the 2 and half turns to start off with, it should be close to there but every Honda a little different.

[gearhead400]

yeah, exhaust is completely stock now.

[trx#9]

yeah, exhaust is completely stock now.

Don't do that, run the aftermarket pipe with the stock filter with no air lid.

[gearhead400]

i cant. i have to be at 98 to 102 db to race this weekend. that pipe definitely doesnt cut it.

[trx#9]

Are you sure the SSQSA checks the DB's.

[gearhead400]

yeah, the rules say no higher than 98, but brett said in the forums i believe that they could be a little higher and he'd let it slide. But i dont have a way to gauge it so i just went back to stock


EDIT: just checked, he said up to 102db but this pipe doesnt have a spark arrestor, so again, cant run it anyway. 

[TRX450R_Racer]

Kyle I have a stock pilot if you need to borrow it.

[TRX450R_Racer]

I think I have an extrs spark arrestor too.

[4fittyr]

48 pilot  180 main k&n  lrd slip on  hrc lid  never had any problems  except for tryin to hang on

[gearhead400]

i got it to run perfect through all the gears with the lid off, k&n, and stock pipe. If you could frank, just help me fine tune it friday or saturday, that would be awesome! I dont want to mess with it since its running right haha.

[TRX450R_Racer]

i got it to run perfect through all the gears with the lid off, k&n, and stock pipe. If you could frank, just help me fine tune it friday or saturday, that would be awesome! I dont want to mess with it since its running right haha.

No problem. I looked through my stuff and I have an extra stock CDI we can try also.

What is your jetting?

[gearhead400]

the main looks like a 160 to me (what came with the bike) so i reinstalled it, put my clip on the 2nd notch, and my fuel screw is 2 turns out. lid on it cuts out at the top of every gear, lid off it runs smooth, no bogging at all.

[TRX450R_Racer]

OK I will take it for a spin and see what I think.

[gearhead400]

your the man!