Rough running in second to third gear

[Niall-griffiths]

Hi all. I have a running problem on my ec 300 2002 second to third gear seems like its got no powerband and just splutters like a weak spark or to much oil mixture this only happens in second and third top end but it also does this throughout he whole rev range not just on the pipe if I don't ride her hard for around 10 mins then it clears when I hold it wide open though the gears for around 20 seconds.

the bike has a messico front pipe fmf power core 2 silencer and has also had he top end rebuilt a few days ago including carb fully cleaned and new plug ... This fault was present before the rebuild tho. I am running castrol fully synthetic 40.1 no spooge or smoking.power valve is also functioning as normal

I was informed when buying the bike it had just been jetted correctly but I think something is not right here as I have good spark fresh top end and powervalve working fine. Any suggestions??

 

[motopsycho87]

Sounds like the jetting is way rich down low / needle. If it clears out after a long run that should be it. Worst case is crank seal, (longer clear out time indicates thicker / more oil) which is an easy job!

Also it may be a spark issue, my cdi failed and gave similar results...

https://www.google.com/url?q=http:/..._cxlBA&usg=AFQjCNEpvIo1SfIFd_7kyys922na_M6eDg

 

[Niall-griffiths]

Sounds like the jetting is way rich down low / needle. If it clears out after a long run that should be it. Worst case is crank seal, (longer clear out time indicates thicker / more oil) which is an easy job!

Also it may be a spark issue, my cdi failed and gave similar results...

https://www.google.com/url?q=http:/..._cxlBA&usg=AFQjCNEpvIo1SfIFd_7kyys922na_M6eDg

Pretty sure it's not crank seal I'm not getting any smoking or loosing any oil from gearbox if it was cdi would it not play up throughout the rest ore gears tho? As they all seem fine.how can I check the jetting is to rich ??

 

[iamovru]

If it sputter`s or blurbs in 3rd and up, it may be the main jet (To Rich). Do you know what size it is?

 

[Niall-griffiths]

Runs rough second and third top end above those gears it's perfect I dont know what size jets are in ATM

 

[iamovru]

Sounds like jetting. If you are wide open you are just blowing it out. Find out what main and report back.


Sent from my iPhone using Tapatalk

 

[Niall-griffiths]

Sounds like jetting. If you are wide open you are just blowing it out. Find out what main and report back.


Sent from my iPhone using Tapatalk

Hi have not got much experience with carbs can I just remove the float bowl 4 screws and shouldi be able to see what size jet in there??? Or do I need to remove the carb completely??

 

[Niall-griffiths]

Before I go any further would like to add the bike idles high and when off clutch in first it's pulling like slight throttle is applied only very small tho. Cable is not sticking or caught anywhere. Also black screw on carb (I presume idle screw) is fully screwed in.

 

[savage sausage]

Hi have not got much experience with carbs can I just remove the float bowl 4 screws and shouldi be able to see what size jet in there??? Or do I need to remove the carb completely??

take off the carb and unscrew the 4 float bowl screws,you can then undo both the pilot (smaller) and the main jet (bigger) and note their sizes..also see which clip position the needle is at.

check this out and it will help you if available print it off like I did

http://www.duncanracing.com/TechCenter/KeihinCarbJetting.pdf

 

[gasgasman]

I say spark plug. I was fighting the same concern on my bike.

 

[Niall-griffiths]

I say spark plug. I was fighting the same concern on my bike.

Replaced plug with new one when i done top end made no difference

 

[savage sausage]

Hi have not got much experience with carbs can I just remove the float bowl 4 screws and shouldi be able to see what size jet in there??? Or do I need to remove the carb completely??

did you take a look at that site?? it will help you understand how best to set up your carb

 

[Niall-griffiths]

Just took e carb apart and I can only see one jet I removed it with a flat head screwdriver and the number is 42 I can't see another one in there tho? Will up,our pics later

 

[Niall-griffiths]

Ok found it was being stupid. I have jets number 178 and 42 also the needle has numer 7 engraved into it. Both jets and needle have a sighn like the alpine star stuff engraved into them as we'll

 

[john r b]

This sign is the manfu. logo Keihin

 

[pscook]

Also, the 7 is for the slide. You need to remove the needle from the slide by unscrewing the cable holder inside of the slide and look at the markings (three or four letters or number combinations) near the grooves. And take note (and write it down) of the clip location (which groove it's in). Clip position is important regarding how the bike runs.

If the clip is too high, the needle is too low, and the bike will be too lean. If the clip is too low, the needle is too high and the bike will be too rich. High clip position means away from the taper, low clip position means closer to the taper.

Al that I can say is write down all of the screw, needle, and jet information on a piece of paper that you won't lose or misplace. This is important information to get the bike running to your satisfaction.