any ideas for mixture setup with fullsystem racing exhaust

[Jundie]

i've put on an full system laser k1 racing exhaust on my bike, its an EK model with standard airfilter, i'been riding small trips and nticed that it pulled little less than im used to, i've tryed topspeed and it came out 15 km/h lower. i've rode 60 km and the engine was extremely hot, even the frame was too hot to touch near the engine. the bike had enough oil though, after the highway and full throttle it made some scary noises..    
well i guess it got very lean now and gets hot because of that (sparkplug -> glow plug idea)
so anybody got a fullsystem exhaust on their bikes, how was your mixture setup??

am i thinking in the right direction?

[cummuterguy]

yeah, definately need to re-jet. the exhaust lets more air out, thus more air comes in, even with just a standard air filter.

What year is your bike? 2001 and up have different carbs then the 00 and earlier, so year model will help determine what jets you need to get, etc.

If it's getting that hot, stop riding it til you re-jet. You don't want to damage the motor. That funny noise you were hearing was probably detonation... not good.  pull your plugs, I bet they are white, maybe even a bit melted on the tips.

Anyway, post your year model, and also any other mods you have done, and one of us will be happy to get you headed in the right direction.

[Jundie]

thats the strange thing, the plugs are cofee brown and thats just the right color right?


i'm thinking of one other thing, maybe for some reason its not getting enough oil? or is that too much wild thinking

EK model--89 european bike

[cummuterguy]

i'd still re-jet,

You have a euro bike, so your primaries are already #40's, keep those.  Not sure what your mains are, but I'd bump up to at least a 127.5 with 2 washers under each jet needle or 145's with one washer. (sounds like mid-throttle is lean, so I'd go larger mains with less washer, personally)

here's a how to with pics (not mine, I think it's Jeff's)

http://www.angelfire.com/mt2/mikesgs500/rejetting/

[Jundie]

ok according to haynes (i myself never looked into the carbs to see what sizes i got  so how can one see??? numbers on the jet itself or measure their sizes somehow???) 40 pilot jet  120 main jet  and 1 1/4 turns out

i'though of drilling out the 120 jet is that a good or a bad idea (the shops are closed and im low on cash    )

and #4 washer...? like a washer for M4 or what?

[cummuterguy]

120 main.... not good, and don't try to drill it... it's been discussed before in here.

mains are cheap anyway, I'd suggest you get a few different sizes to experiment with.

#4 is s.a.e. measurement, I'm not sure what the metric equiv is

[V8Pinto]

bump up the mains.  I'd go with at least 135's.  Drop a Uni or K&N in the stock airbox and you're good to go.

[Jundie]

ok made a change today, adjusted the needles to their highest position, the circlip was in the middle position 3rd groove from top and from bottom. i replaced it to the lowest position and thus the height is 2-3 mm up on the needle, the bike runs much better in the lower rpm but high up its short on power, i'm gonna put my original pipes with a weldon laser k1 tomorrow and find a place where they sell the jets. i'm glad to hear they're cheap

[V8Pinto]

I just bought a set of jets for my GS at a Yamaha dealer, $6.50 for two mains.

[Jundie]

ok i ordered 130 for my bike...what do you think? good choice?