Trx405R carb ?

[red416ex]

i have a 05 450R with a HRC cam, port and polished, and wiseco standard bore and comp wiseco piston and it will idle fine and die out of nowhere. i took it back to the mechanic that built it for me and he says i need a new carb either off a crf 450 or a 06 or newer trx 450. I am at a loss and dont know what to do any ideas?:confused:

[d3ktrix]

You don't NEED to change the carb. The stock 05 carb is perfectly capable of handling the mods you have.

Most likely it either just needs to be cleaned or re-jetted.
Air leak is also a possible cause for your problem.

What is your jetting?

Even though the CRF450 / 06+ TRX carbs are better, you don't NEED one.

[red416ex]

I bought a dyno jet kit and installed 175 main jet as the instructions said to run with no air box lid and aftermarket exhaust ( i also have a full white bros system) for the altitude i live in which i live on the southern gulf coast.

[d3ktrix]

Well a 175MJ Dyno jet is about equal to a 195MJ keihin jet.
Which even for your setup is probably too rich.
But that shouldn't make your bike stall on idle, most likely one of the other jets are off too.

Are you also running the Dyno jet needle
and pilot?

For us to recommend you jets, you would need to ditch the dyno jet kit and buy all keihin jets.

This chart shows the size differences between the jet manufactures.


Width------Kehein # -- DynoJets # -- Mikuni #
0,0350---- 92,5--------- 92----------- 86,3
0,0360---- 95----------- 94----------- 88,1
0,0370---- 97,5--------- 96----------- 90,0
0,0380---- 100---------- 98----------- 91,9
0,0390---- 102,5------- 100---------- 93,8
0,0400---- 105--------- 102---------- 95,6
0,0410---- 107,5------- 104---------- 97,5
0,0420---- 110--------- 106---------- 99,4
0,0430---- 112,5------- 108--------- 101,3
0,0440---- 115--------- 110--------- 103,1
0,0450---- 117,5------- 112--------- 105,0
0,0460---- 120--------- 114--------- 106,9
0,0470---- 122,5------- 116--------- 108,8
0,0480---- 125--------- 118--------- 110,6
0,0490---- 127,5------- 120--------- 112,5
0,0500---- 130--------- 122--------- 114,4
0,0510---- 132,5------- 124--------- 116,3
0,0520---- 135--------- 126--------- 118,1
0,0530---- 137,5------- 128--------- 120,0
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
0,0870---- 222,5------- 196--------- 183,7
0,0880---- 225--------- 198--------- 185,6
0,0890---- 227,5------- 200--------- 187,5

[red416ex]

yes i also have the dyno jet needle and pilot jet installed.

[red416ex]

what about using HRC jet kit?

[400ex07]

The jet kit shouldn't be the problem, If you followed the directions, the jetting should be very close. but I would try cleaning the pilot jet and maybe trying a bigger or smaller pilot jet depending on what you need, and try messing with the air fuel screw.

[d3ktrix]

Originally posted by red416ex
what about using HRC jet kit?

Would work, but only comes with the Main and Needle. Would still need to by a pilot.
And over priced for only coming with 1 of each jet.

Check out http://www.jetsrus.com

Have you tried cleaning the carb yet?

[400ex07]

I saw the directions for that dyno jet kit.
Did you plug the hole that is supposed to be plugged according to the directions? I don't know if that has anything to do with it but it could. Also I am pretty sure dynojet does not make pilot jets, so maybe you still have the stock pilot?? which would probably be the problem

[d3ktrix]

Stock pilot is a 48, even if its on the lean side it wouldn't cause the bike to cut off.

Tell us more about your problem.

Does it start easy hot and cold?
When does it die?
How does it run through the rest of the throttle range?

[red416ex]

the carb has been cleaned and still the same the diaphram is in good shape as well. the bike was jeted orginaly before the build with the dyno jet kit and had a ESR intake and the exhaust and ran fine so we had the jetting right once before. now it will fire up realy easy if you choke it the first time of the day and will idle for a good min or so perfect you can rev it up and everythings fine then you try to let it sit and idle it just pops and dies out of nowhere. it will fire back up fine and sit there and run for a min or so still and dies the same. so i hope this helps thanks for all the help.