Jump to content

Carb Problems?


Recommended Posts

nice forum guys!!!, stumbled upon it from one of your members electrical pages... i need a little advice, i've got a carb problem, or so i think ??? now starting to look in other areas...here's my posts from another forum....

 

well, my problem is, well, i'll give a little background first....had a 300 ex a long time ago, traded it in with a jet ski for a newer gp1200r, got into buying and selling motorcycles and low and behold i got a couple quads as trades on a gixxer750.....so now i have a 440 ex that hits strong as i've ever seen cam, big bore, sparks exhaust, supposedly some head and carb work, triple rate front reservior shocks etc....and this banshee...that supposedly had a new top end (just like every other two stroke for sale...lol...) and was just finished 0 hour, before i traded for it...well, whenever i went to test ride it he told me that the bike just falls on it's face really bad whenever you come off of idle and never picks up...and he was right..it idled fine, but wouldn't do much of anything else...well, he said, " i think it might need to be rejetted, well, turns out that was part of the problem...it had no jets in it!!!!...so, i went to the toomey website, it suggested 270's for a t5 with filter and no lid....well, this was WAY too lean....hit idle to mid then just crapped out...soooo...went to 320's...well, this really helped...but still not great..so, i checked to see if the carbs were in sync..they were a little out...got that fixed...got it idling right....the air screw are about 2.5 turns out from full in, needles are on 4th notch from top...320 jets ....the only thing i haven't checked is the float bowl setting which seems like it might be my problem or maybe it's jets??? That's my question...it's pretty bad off idle, maybe i'm just expecting too much....then all of a sudden it will pick up..and in first it will lift the front wheels a bit, but then kinda gives out on the top end??? i've ridden a banshee with around the same mods except for it had a cool head and boost bottle..it was alot faster, picked up the front end in at least the first three gears...compared, the one i've got is acting weak....what do you guys think it is??? plugs really don't have too much color to them yet...one side seems kinda clean, too clean....white base...black electrode..the other has a black base (porcelian (sp?)) with a black electrode....i checked the cylinders and the exhaust with a pyrometer and they seem to be within acceptable numbers, within a few degrees of each other at idle....so what do you all think???

thanks,

-matt

 

well, it's not white like a white that'd show from overheating....and it's the one on the left side, (choke side)....it's like a white like it's almost new like it's not firing or something...and the cylinders are running, or seem to be, at the same temp....per the pyrometer....also...the bike, i'd hope wouldn't need carb rebuilding yet??? it's an 02..has stock tires with about 50-70% of the tread left on them...

 

btw, the plugs seemed almost wet...way rich, but the *beep* thing fell on it's face pretty bad with 270's....btw...checked again and they are 310's...should i go back ??? the floats, needle and seats and everything seem to be in spec and functioning well???

 

.....btw, i checked the reeds...all seems well....and i took a look at the pistons through the ports...they do actually look new...wow...lol...

 

ok went back with another suggested carb setup....280 mains, stock pilots, 1.5 turns out on the air needle, needle clip one from top...runs about the same, little better on bottom, but still dead on top....what problems are associated with the tors boxes? can i gut them? can i just unplug them from the harness???

 

how probable is it that it's a weak stator, coil, or cdi box?? i put the old jets in it and low end got a little better, but still top end suffers, almst like it's hitting a rev limiter or something...still only pulls till about half of where it seems like it should??

 

 

ok, after all the supposed carb problems.....after reading one of your forum members electrical pages, great page btw, i'm starting to think it might be the coils.??? any suggestions???

Link to comment
Share on other sites

It doesn't sound electrical to me, I think you're on the right track with the jetting. Bottom end power is pretty nonexistant, higher compression will help like the other one you rode, but it shouldn't fall off in the midrange and upper RPM's. You can unplug the TORS boxes and control box, but unless she won't rev at all above idle it probably won't change anything (Banshees don't have rev limiters beyond the TORS system).

 

Anyway, depending on your elevation, premix ratio and mods (you say filter, is it K&N or foam?), you should be close on the jetting. I would do a plug chop on the 310's and see for sure if it's rich or lean and go from there, your pilots, airscrews and needle clip position should be allright but you need to dial in the mains.

 

BTW you might check out the Jetting FAQ below, good luck.

Link to comment
Share on other sites

If just one plug is white and the other is not it could be an air leak. Checks the carb boots by spraying ether or something around them. If the idle chages it's the boots suckin air. Could be a crank seal also leaking. Another thing to check is that the choke tube is between them and the right slide is in the right carb and vise versa. If you look at the slide it has a section cut off the bottom. That angled cut should be facing the airbox. If not the slides are in the wrong carbs.

 

Also spray the ether on the carb tops etc...

Edited by fixitrod
Link to comment
Share on other sites

ok, good news...unplugged all the tors stuff and it ran pretty good, about like the one in the mustang vs. banshee vid, or so it seems....still sputters in the mid, but i think that's actually from the needle being set really low....(2nd from top)....i'll go on the 4th clip and i think it'll run without the sputtering transition..

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...