Quick Jetting help...

[grant14]

i have a 2006 450er that has a full yoshimura pipe on it with no air box lid that was dyno tuned with a 185 main 48 pilot and the stock leak jet. has a hrc needle 4th clip down. i am putting a 13.5:1 piston and a hot cams stage II cam in it. Along with C12 fuel 50/50 mix.

I assume that i will need to go a bit richer, anyone have any experience whith how much it will change with these mods?

thanks,
Grant

[DnB_racing]

Originally posted by grant14
i have a 2006 450er that has a full yoshimura pipe on it with no air box lid that was dyno tuned with a 185 main 48 pilot and the stock leak jet. has a hrc needle 4th clip down. i am putting a 13.5:1 piston and a hot cams stage II cam in it. Along with C12 fuel 50/50 mix.

I assume that i will need to go a bit richer, anyone have any experience whith how much it will change with these mods?

thanks,
Grant This has the fcr carb?? I have all the mods listed plus a little more, and im running a 170 main with all c12 and a plug chop has it spot on!! at 170 and 48 pilot and 50 leak jet at under 3000 feet with stock plug indexed

[grant14]

So that is what the local honda shop that has a dyno set it at. i recently bought the bike, wasn't happy with the power so i added the pipe and pulled the lid off. had them dyno/jet it, still wasnt really happy, hence the piston and cam.

Jetting seemed ok, but like i said i wasnt happy with the power...

[DnB_racing]

Originally posted by grant14
So that is what the local honda shop that has a dyno set it at. i recently bought the bike, wasn't happy with the power so i added the pipe and pulled the lid off. had them dyno/jet it, still wasnt really happy, hence the piston and cam.

Jetting seemed ok, but like i said i wasnt happy with the power... I just saw that its dynojet ok ya that might be right I dont have the conversion chart handy... your saying they put it on a dyno machine and used dyno jets correct?? I misunderstood you at first.. what type of numbers did you get from the dyno runs

[310ESR]

I'd change the leak jet to 50 or 55

[grant14]

so lets start over. used a dyno...but used regular honda jets

[quad71]

Ok what filter do you have? my set up 09 stock piston hcstg2 sr4 slipon uni air filter no boxlid green wire mod 94 octane 165 main 42 pilot 55 leak hrc neddle fuel screw 1 3/4 turns out #8 sparkplug.

[DnB_racing]

Originally posted by grant14
so lets start over. used a dyno...but used regular honda jets is it an fcr carb?? and by regular honda jets do you mean keihin? if so 185 is huge for your mods, it doesnt make sense...

are you sure they didnt use dyno jets????that the only thing that would explain the large size

a dyno machine is very expensive to use!unless you asked to have it dynoed they wouldn't just do it to tune it, and if they did you would get a sheet showing your peak hp and torque and they would have needed different jets to tune it to. Most dealer shops dont have dyno's

[grant14]

fcr carb... honda jets...

our local honda shop has a dyno. and although not cheap for 200.00 they will run it and jet it with the dyno. and at the end you get a hp/tourque sheet. and if i had time, i would probably let them run it again, but they are booked out 2 weeks, and i just finished up putting in the new piston and cam in last night. want to go race this weekend.

the 185 seemed big to me too, but based on the last run, jetting was right on, with just a bit rich at the very top. they recomended keeping it that way based on the riding i do. motocross and sand...

[DnB_racing]

what do your plugs look like?? if they are the nice goldish color down inside like its supposed to be then just run what you got ...

I wouldn't worry about starting it to lean with that big of a main in there, then do a plug chop and adjust from thereafter your mods..

[jlrenken]

its kinda off topic but what is a plug chop.

[DnB_racing]

Originally posted by jlrenken
its kinda off topic but what is a plug chop. its a method of checking if the quad is running lean or rich or right on by, using a new plug and shutting it off at high speed and reading the plug color... there should be a good explination about it in google

[grant14]

i will go through and do the plug chop...

I just figured that these mods were pretty common to do at the same time, thought somebody might recall how much of a change they had to make for a starting point.

[DnB_racing]

i went from no air box lid and hrc head pipe used i think around a 150 main then i went to many mods like your going to have and went to 170 main, but there is no way you need to go to 200 lol


your right you will get a better result doing the plug chop

[Ruf Racing]

Originally posted by grant14
i will go through and do the plug chop...

I just figured that these mods were pretty common to do at the same time, thought somebody might recall how much of a change they had to make for a starting point.

Common mods. they are. But every bike, with different environmental conditions, can require a different setup. As mentioned, you will only know for sure, what is the correct jetting, is by doing the plug chop. Good luck! :)

[Pacheco_450r]

Originally posted by DnB_racing
I just saw that its dynojet ok ya that might be right I dont have the conversion chart handy... your saying they put it on a dyno machine and used dyno jets correct?? I misunderstood you at first.. what type of numbers did you get from the dyno runs


Width------Kehein # -- DynoJets # -- Mikuni #


0,0540---- 140--------- 130--------- 121,9
0,0550---- 142,5------- 132--------- 123,8
0,0560---- 145--------- 134--------- 125,6
0,0570---- 147,5------- 136--------- 127,5
0,0580---- 150--------- 138--------- 129,4
0,0590---- 152,5------- 140--------- 131,3
0,0600---- 155--------- 142--------- 133,1
0,0610---- 157,5------- 144--------- 135,0
0,0620---- 160--------- 146--------- 136,9
0,0630---- 162,5------- 148--------- 138,8
0,0640---- 165--------- 150--------- 140,6
0,0650---- 167,5------- 152--------- 142,5
0,0660---- 170--------- 154--------- 144,4
0,0670---- 172,5------- 156--------- 146,3
0,0680---- 175--------- 158--------- 148,1
0,0690---- 177,5------- 160--------- 150,0
0,0700---- 180--------- 162--------- 151,9
0,0710---- 182,5------- 164--------- 153,8
0,0720---- 185--------- 166--------- 155,6
0,0730---- 187,5------- 168--------- 157,5
0,0740---- 190--------- 170--------- 159,4
0,0750---- 192,5------- 172--------- 161,3
0,0760---- 195--------- 174--------- 163,1
0,0770---- 197,5------- 176--------- 165,0
0,0780---- 200--------- 178--------- 166,9
0,0790---- 202,5------- 180--------- 168,8
0,0800---- 205--------- 182--------- 170,6
0,0810---- 207,5------- 184--------- 172,5
0,0820---- 210--------- 186--------- 174,4
0,0830---- 212,5------- 188--------- 176,3
0,0840---- 215--------- 190--------- 178,1
0,0850---- 217,5------- 192--------- 180,0
0,0860---- 220--------- 194--------- 181,9

[4ABURN]

I would try the jetting you have know for starters lots of fuel I think!