Exhaust slightly glowing red, help!!!

[mineralgrey01gt]

Some of you may know I just recently finished my overhaul. Well its up and running but I still think the jets are off some. The exhaust will glow red after just a few minutes of running. I have a 175 and 50 in it. Do i need to drop the 175 to a 172 or so? Keep in mind I didn't have the airbox on it nor a filter, just straight carb to get it to run for the first time. Mods in sig

[Thumpin440ex]

If the pipe is glowing, it is running lean.. So the jets need to be upped

John

[mineralgrey01gt]

think I should try To adjust air screw also? This carb came from up north so it is probably set different, I'm going to pull the plug tomorrow, check it, and put the correct heat range plug in it (it's 1 range hotter right now)

[JOHNDOE83]

Yeah deffinetly lean, Id go up in jets to atleast 175 and put on a filter....

Even with the filter you may need a 180, if you put on your airbox and filter a 175 might be enough but its hard to say from only reading post's.

I always run slightly rich, I go big on jets till it stutter's on the top end then back down jet sizes untill it stop's and it seem's to run perfect all the time, runs cool and make's great H.P. and speed.

Also the 450r carb let's in alot more air, this means you need to up the fuel to compensate, if I were you, Id try a 190 and if it start's to stutter on the top end go down a few size's till it stop's.

[mineralgrey01gt]

Originally posted by JOHNDOE83
Yeah deffinetly lean, Id go up in jets to atleast 175 and put on a filter....

Even with the filter you may need a 180, if you put on your airbox and filter a 175 might be enough but its hard to say from only reading post's.

I always run slightly rich, I go big on jets till it stutter's on the top end then back down jet sizes untill it stop's and it seem's to run perfect all the time, runs cool and make's great H.P. and speed.

Also the 450r carb let's in alot more air, this means you need to up the fuel to compensate, if I were you, Id try a 190 and if it start's to stutter on the top end go down a few size's till it stop's.

I went and got the jets today. I was also told the pilot may be off? So i bought a 52 and 55 pilot just to have them and got a 178 and 180 jets also. I hope this works, i am going right now to put the airbox on with the filter and see how it runs

[brokenmike]

Don't bother jetting it till you are done it. You are just wasting your time. Put the air box and filter on then jet it.

[mineralgrey01gt]

That's what Im going to do. I'll post up about it

[mineralgrey01gt]

ok guys, this is what i accomplished tonight. All runs made with filter and box no lid:

1st trial run (RAN THROUGH THE GEARS AT 1/2 THROTTLE THEN KILLED IT): 175 main, 50 pilot, needle on 3rd clip, air screw all the way in EXTREMELY LEAN AND EXHAUST STILL GLOWING

2nd trial run (2ND GEAR PULL IN YARD THEN KILLED): 185 main, 50 pilot, needle on 3rd clip, air screw all the way in EXTREMELY RICH but the needle set fell out the carb and we forgot to put it back in

3rd trial run (IDLING): 180 main, 52 pilot, needle on 3rd clip, air screw 2 1/2 turns out STILL VERY LEAN BUT COMING AROUND EXHAUST STILL GLOWING

4th trial run (IDLING): 182 main, 55 pilot, needle on 4th clip, air screw 1 1/2 turns out STILL VERY LEAN BUT GETTING A SLIGHT HINT OF BROWN ON THE PLUG EXHAUST STILL GLOWING

now do i need to up my pilot again? Isnt the pilot for when idling? I have never had this much trouble getting a quad jetted right. I havent tried to make a pass on the last setup yet but am tomorrow to see how it runs. What is everyones opinions on this?

[JOHNDOE83]

I tryd to tell ya...lol..j/k

thats cool... llike I said i have a 190 and still a lil lean.

I think your gettn higher and gettn more power also.

are you backfiring at all? popping?

[mineralgrey01gt]

lol im going to buy bigger jets tomorrow.

its not backfiring much at all. Every once in a while itll blow back through the carb but it didnt do it on the 4th trial setup. I just cant get this thing to lean out and idle without the exhaust glowing red

also biggest main i have is the 185 but like i said that piece wasnt in the carb for that run, put it back in for the next after we found out what it was for.

[JOHNDOE83]

your pilot should be good, needle should be good at middle or higher, main could need to be pretty big, im puttin a 215 in mine and seeing if it breaks up at all.

My 190 and 50 came with the carb and all is good except for the topend I can tell its a lil bit lean, got lucky and everything else was where it should be.

Still have 195, 200, 210, 215 to try out.

[mineralgrey01gt]

my bro has some 190 and up ones at his house i might go grab tomorrow. That will help it at idle going up on the main? I thought the pilot changed the idle lean/rich?

[clemsonteg]

Not sure if the 450 carb is the same but the 400 carb the more out you are on the screw the richer it will run. I would try 3 turns out and see if the exhaust still glows with the 55 pilot, if so you can go up then to like a 58.

[mineralgrey01gt]

ok so i did some research on the net and it seems as glowing red exhaust is common on 400ex's. Alot of people say there plugs are fine but the exhaust will have a slight glow to them. I was running extremely rich before the rebuild and when I would ride at night the exhaust wouldnt glow but from what i understand its because i was so rich. Im thinking if i turn the screw to 2 1/2 turns and leave the 55 in and put a 185 in or a 190 ill be ok.