Hot cam stage 2 jetting??

[jaysun]

I bought a 99 400ex for $500. It is in good shape but has had a hard life. The motor had a rattle sound to it so I had it torn down. Replaced the rockers and put a Hot Cam stage 2 in. It runs so much quieter now and seems to be great. I live in New Hampshire so when I got it back from the install I had to rip it around. We have about 6" of soft snow it was 45 degrees out in January and raining. Anyway when I would crank the RPM's in first gear and shift to second it would bog down like the choke was on. I would try to go back down to first and it would bog in first. If I pulled in the clutch and throttled it then drop back to first it was fine. Do I need to rejet after installing a cam?? Before when it had the engine noise I had no power loss problems. The air filter is brand new and spark plug. Any ideas???

[DaleJrFan]

I dont see your problem being jetting due to you dont have to usually re-jet after cam installation. When you tore the motor down did you take the carb off and drop it or let is sit up side down for awhile? Maybe you messed the original jetting up or something? Has there been a big temperture change cause I run a little lean in the winter and have to re-pack the pipe due to the weather this time of the year, I get a little back fire and some hesitation in 2nd but after my quad warms up its fine.

[zeppelin]

you do need to rejet but i wouldnt be able to tell you the exact jet numbers. just pull the carb off and see what jets you have in there now you will need at least a 42 pilot and maybe the next step up from that. and i would get a main that is one size smaller ( just in case) and the next 4 sizes up from what you have, the only way to figure out which jet is best is to try them all so start with the next biggest first and see how it runs, if its worse then you know for some reason your too rich. most likely though it will make it better and you will keep going up on the mains untill it boggs down under load, then you go down one size ;)

[Barney]

You do have to rejett with the diffent cam. Take the carb a part
see what is in there. Mine ran good with 40 or 42 pilot main
152 to 160 but allso look at the needle it should be in the stock setting. And this should work.

[jaysun]

I called the place that did the work on my engine. They told me that it could be my idle. Does this sound right? I have not had a chance to adjust it yet. I just wanted to see what others thought. Would this change the way my throttle responds?? Sometimes working well and sometimes bogging down....

[zeppelin]

its only your idle if it is idleing too high or if its dying becuase of idleing too low. something that will deffinitly need to be adjusted is you fule screw it on the bottom of your carb and the only way to adjust it is threw trial and error (because tempetures and humidity actualy affect it) just play with that untill it doesnt backfire any more. but if it runnscrappy then its deffinetly your jets

[jaysun]

It will idle ok. but after about 3 min. it will stall out. I will see what the adjustment does for me. Thanks.

[jaysun]

I tried to adjust the screw underneith the carberator. It did not change the idle. It just kept spinning and looked like it was going to break. After that I just warmed it up pretty good, and the idle would sound like it was fine. Then it would slowly go down then almost stall then creep back up to a good sounding idle??? Any ideas?? Not a quick up and down idle just really slow from high to low....?

[h400exrydr]

that idle might b from the different cam. i know that there are some 4 stroke motors that have a crazy cam in and they wont idle worht crap. and if your cam is brand new you are suppposed to run it for like 30 mins at above 2300 rpms or somethin close to that, hope that helps