Jettin after 450r carb, Concerned.

[ImplodedMindZ]

I didnt wanna mess w/ the inital jettin tryin to find what would work so i took it to a shop. Well when i got it back it is a PITA to keep runnin when its first started. its got a Keihin 50 Pilot and 160 main. Before on the stock carb i could start it right up w/ no choke and it would run no big deal, i wouldnt have to mess w/ the throttle or anything to keep it runnin. I wanna try to get this 450r carb to that point. My jettin on the stock carb was 38 pilot 165 main. So where should i go from here to try to get easier starting.

Also i went riding on it yesterday and it seemed to be runnin super hot, at the end of the day smoke was comin out the exhaust(thats when i stopped ridin). Does anyone think that w/ my mods a 160 main is pretty lean? I am at about 1200ft. at the end of the day it seemd to be idleing really high whenever i stopped. i am gonna check today for any air leaks but still everyone else seems to be running 170-180 mains at least. THanks for any help.

[ImplodedMindZ]

well there werent any air leaks, the boots were still on there and tight. The shop i took it to couldnt finy anything wrong w/ it. When i get it back im gonna look over the carb and throttle cable to make sure nothing is binding possibly keeping the throttle from closing all the way when i let go.

Anyone feel like chimeing in on the jetting question?

[GPracer2500]

Did they jet it on a dyno? My opinion--->don't ever bother paying a shop to jet anything unless they are using a dyno. All most shops (without a dyno) are going to do is get things sorta close and call it good.

I'd get a rage of jet sizes and start experimenting. Experiment with the fuel screw too for your starting issues. If you suspect it may be running lean than fatten it up and see what happens.

[ImplodedMindZ]

no they didnt jet it by a dyno. there is a guy around close by that has one and i think its only like 80$ to do it but i dont know where. I think im just gonna go ahead and buy some jets and try and do it myself. iv read alot on it i am pretty confident i can get it done but can anyone gimme an idea of where to start main jet wise?

[lpmaster]

im not sure of your elevation, but with similar mods at sea level im on the button with a 48 pilot, and 190 main, 160 is way lean, you should be hearing some backfiring during hard acceleration when your pinned witht hat jet, get a 180 - 200 K main jets, make sure your a/f screw is 2-3 turns out

[ImplodedMindZ]

Originally posted by lpmaster
im not sure of your elevation, but with similar mods at sea level im on the button with a 48 pilot, and 190 main, 160 is way lean, you should be hearing some backfiring during hard acceleration when your pinned witht hat jet, get a 180 - 200 K main jets, make sure your a/f screw is 2-3 turns out
Awesome thanks alot thats kinda what i was lookin for a starting point. i hear popping when decelerating but not when accelerating. Ill proly leave the pilot in there for now and get some main jets to experiment w/ next week.

[lpmaster]

ya, decel is a good sign of lean as well, make sure the air/fuel jet is good because 50 is a big pilot and shouldnt need changing, pop on decel can also be a lean pilot circuit(idle circuit) as just a lean main

[ImplodedMindZ]

I think i traced down a few of my problems today. I noticed that whenever i barely pulled on the throttle cable sheath that the motor throttled up a lil so the cable was just to tight. I put some more slack in there by adjusting it out a lil and i hope that will fix my problem w/ eratic high idle when i stop.

and the major thing is it seems that when that shop put my carb back on they didnt get a very good seal on the air-boot to carb, on the motor side. Its kinda just sittin up against there. So im guessin that is proly a major problem w/ my lean situation. So Ill tighten that up and probably this weekend buy some jets and spend a few hours tuneing what main i need.

[ImplodedMindZ]

Thanks for everones help. i think im finally on the right track. I changed my main to a 170 and it was still runnin pretty hot/lean. I bought a XRonly temp/oil dipstick and it showd my oil @ like 275 @ its highest and thats w/o really beating on it. So im changed to a 175 main and it got better. iv got a 180 and 185 to put in now so i am just gonna keep goin up till i see no more gain.

[ImplodedMindZ]

Iv been slowely workin out all the kinks in the carb, but iv got a quick question. When i rev the bike up it takes a few seconds for the engine RPM to stabilize back at idle after i let off the throttle. I took the cover off the side of the carb all the lingage that the throttle cable is hooked to is returning to normal but engine RPM isnt folowing right there w/ it. All carb settings are below and i have a stock needle w/ clip in 3rd position from top. Whats next?

[GPracer2500]

Hanging idles are usually from a lean pilot circuit. That leaness could either be because of an air leak or incorrect pilot jet.

[ImplodedMindZ]

I checked my air boots yesterday so i dont think airs leakin there. So i guess ill try to go up on the pilot next time i get a chance to take the carb off. Thanks.