Yamaha R6 Forum: YZF-R6 Forums banner
1 - 10 of 10 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
Hi everyone,

Just bought a 2002 R6 back in December and have been reading a lot on here and now I'm making my first post hoping to get some help. The bike has 10k miles on it and I am the second owner, the original owner said he barley rode it anymore and needed to get rid of it.

When I picked it up it started right up with the choke and then would idle no problem with no choke once it warmed up. However when you would give it some gas it would bog down, I assumed that it just needed the carbs cleaned. The original owner said he had the carbs cleaned on it a couple years ago but its basically been sitting since then.

So I got it home and pulled the carbs off. You could tell that they have been pulled off before by someone who didn't know what they were doing. Screws were stripped out, some over tightened and some things not even tight at all. The float bowls and gaskets were a mess and the rubber cover was caught in the boot under the #4 carb. The main jets and jet needles were in the wrong positions as well. I have cleaned everything and put everything back into the stock position (148 jets in #2 and #3 and 152 jets in #1 and #4). Put it all back together and started it.

THE PROBLEM:
Bike starts and idles fine. I can roll on the throttle and it will rev up but it still sounds bogged down. If i give it a quick throttle pulse the revs die down and sometimes the bike will stall. It looks like my number #2 cylinder is drenched with gas but i don't know why, stock jets and needles and float height appears to be good.

My next step is to replace my spark plugs and check the ignition coils, any possibility this could be the problem?

Would getting a jet kit fix the problem?

Is it okay to run the bike without the airbox on it?

Only mod to the bike is a yoshi slip on.
 

Attachments

·
UR B-hind Da 8 Ball
Joined
·
6,311 Posts
See all that crap in the carb bowls? That is what happens to gas as it sits. There is more of that in the passages of the carbs, and it has plugged up the emulsion tubes and the jets, as well. You need to remove the jets and emulsion tubes they screw into. Clean out the tiny holes that are cross-drilled in the tubes and the hole in the main jets. You need to remove the pilot jets and clean them up. They have a hole in the bottom and have cross drilled holes in the top. You also need to clean the passages in the carb bodies and make sure they are not plugged. Finally, there is a tiny brass oriface under the top diaphragm cap on each carb that you need to make sure is not plugged up. While you have the diaphragms out, hold them up to a light and see if you see any pin holes in the rubber diaphragm.

Welcome to the world of carburated bikes!
 

·
Mr. HER6
Joined
·
2,084 Posts
Yes, running without the airbox while working on it is not a problem. The fuel drenching the #2 cylinder is likely the symptom of your root problem. My guess is a bad pressure regulator or something along those lines where fuel can flow through the diaphragm and get sucked into the vacuum line. That will make it run like garbage, if at all.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #4 ·
I did clean everything when I had the carbs apart. Soaked everything in carb cleaner for a half hour or so (main jets, pilot jets, emulsion tubes, etc.) and sprayed cleaner in every hole I could find. Maybe something is still blocked?

The diaphragms all looked good and none of those holes are blocked. When i had the bike running the other day they would all open equally.

I'm not sure I know what pressure regulator you're talking about, or vacuum line.
 

·
Mr. HER6
Joined
·
2,084 Posts
I thought your bike had a vacuum operated fuel pressure regulator, but now that I look at the parts diagram it looks like it doesn't.

Either way, you need to try to track down where that excess fuel is coming from.
 

·
Big ol pile of them bones
Joined
·
1,620 Posts
Float needles are probably shot, I would definitely change them.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #7 ·
Float needles are probably shot, I would definitely change them.
With all the bowls off all the floats are sitting at the same height and are all springy when you press on them. Or could there still be a problem even tho they appear to be fine?
 

·
Big ol pile of them bones
Joined
·
1,620 Posts
With all the bowls off all the floats are sitting at the same height and are all springy when you press on them. Or could there still be a problem even tho they appear to be fine?
They have a rubber tip on them that wears out, sitting for long periods of time without being used speeds this up.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #10 ·
did you get it figured out? i am having the exact same problem, have cleaned the crap out of the carbs and still have the bog

I pulled the carbs again and gave them another good once over. Replaced the float needles, lowered the float height just a tad, new spark plugs and a new battery. Shes running good now. Exhaust pops like crazy but a jet kit will fix that as soon as i feel like pulling my carbs...again.


Sent from Motorcycle.com Free App
 
1 - 10 of 10 Posts
Top