Bike seems to bog down while riding

[ng86]

I just cleaned/synced the carbs to the best of my knowledge, took it for a test ride and now it seems to bog down and not get up like it used to..

Any ideas? Thanks

[ng86]

One more thing, now it randomly revs up for about 10 secs then drops back down, it also hangs for a few secs when I twist the throttle. Any help appreciated! Thanks

[SouthendChris]

That seems to suggest you have an air leak either where the carbs attatch to the inlet stubs or where the airbox attaches to the carbs. check all these joints are 'straight' and secure.

I'm sure others will chime in with other helpfull suggestions

Chris

[nortstudio]

Sounds like Chris is right - air leak would be the first thing to check. If you just did a carb sync, maybe the boots are not reinstalled securely?

Try spraying some WD-40 or starter fluid around the boots - one at a time, and wait a moment to see if there is any change in RPM. If so, air leak. Ideally, there should be no leaks to allow the fluid to slip into the carb.

Good luck.

Scott

[yamaha_george]

Sounds like Chris is right - air leak would be the first thing to check. If you just did a carb sync, maybe the boots are not reinstalled securely?

Try spraying some WD-40 or starter fluid around the boots - one at a time, and wait a moment to see if there is any change in RPM. If so, air leak. Ideally, there should be no leaks to allow the fluid to slip into the carb.

Good luck.

Scott

hi,
the guys are on the money with the air leak but also make sure that your cables are not stiff and are lubed properly every little helps.

[ng86]

Thanks for the replies guys, I've gone over it and checked everything I swear. I even took the boots off and inspected them for cracks or holes, and checked the seals on the carbs. I made sure they were seated correctly, and snug. Yg, I did check my cables to see if they were too tight and everything seemed perfect. I bought my bike without the airbox. It came with the dual k&n's and I'm pretty sure it has a jet kit but I'm not sure. One of the jets says factory on it so I'm guessing that's factory pro.

It seems like when I open it up in first and second, sometimes third, it kinda gurgles. I was thinking maybe it was trying to burn up too much fuel? Should I adjust the fuel mixture screws? I'm pretty sure I left them at 3 1/2.

Anyway thanks!

[sweekster]

I'm curious as to how you synched the carbs. Details please. I sounds, to me, you have a rich condition happening.

[ng86]

I'm curious as to how you synched the carbs. Details please. I sounds, to me, you have a rich condition happening.

My buddy has a motion pro synchronizer, so we hooked it up to 1&2, 3&4, and 2/3, left the fuel mixture screws where they were and went to town. Put it all back together and took it for a ride and that's when that started happening. So I'm thinking maybe 3 1/2 is too much?

[nortstudio]

Duane may be right, you may be running rich. Did you do any sort of plug chop? Also, if I understand correctly, you are not really sure which jets are in the carbs?

[ng86]

Duane may be right, you may be running rich. Did you do any sort of plug chop? Also, if I understand correctly, you are not really sure which jets are in the carbs?

Plug chop? Not quite following you there. There's one jet in each carb that says factory on it, it may be the main jet.
I've had my bike since August of 2010 and it ran perfect when I first got it, so either something wore out or I adjusted something incorrectly. I was thinking of getting new emulsion tubes awhile ago but I never did.

[nortstudio]

If it ran ok to begin with, then the jets should be ok (although I guess this isn't an absolute).

A plug chop is running the engine (under load), killing the engine during rev (obviously with clutch pulled in to prevent disaster), and safely pulling to the side of the road. Then you check your plugs, which would then represent how the bike was working in that range when you killed the engine.

With this bike, it would be a pain in the neck. So you might just check your plugs. They should have some indication of the way fuel is being dealt with. There are some great picture tutorials on the web about how to read a plug.

[ng86]

If it ran ok to begin with, then the jets should be ok (although I guess this isn't an absolute).

A plug chop is running the engine (under load), killing the engine during rev (obviously with clutch pulled in to prevent disaster), and safely pulling to the side of the road. Then you check your plugs, which would then represent how the bike was working in that range when you killed the engine.

With this bike, it would be a pain in the neck. So you might just check your plugs. They should have some indication of the way fuel is being dealt with. There are some great picture tutorials on the web about how to read a plug.

Yeah that would definitely be a pain.. I checked all the plugs yesterday actually. 1,2, and 3 seemed normal maybe a little hot, but i'm pretty sure 4 had a little oil on it, it was pretty black. Might have to just bite the bullet and replace the piston rings, and while im in there do a much needed valve adjustment. But even that might not remedy my problem.

[sweekster]

My buddy has a motion pro synchronizer, so we hooked it up to 1&2, 3&4, and 2/3,

I remember doing it this way when I first jumped into the synching deal and that last part pretty much messed things up-causing me to do it again. Granted, I used a home made synch tool and it took longer but still in the end the bike ran perfectly to the point a few people thought it was efi. That's my experience with doing it that way. Anyway, you're gonna hate me but I'm suggesting you do the synch again. This time paying a little more attention to what noises the bike is making. During your adjustments blip the throttle to about 3k rpm to purposely unsettle it. You'll know where you are at when it comes back down to idle. If it hangs before it settles then it's lean. If it drops below then comes back up to idle it's rich. The mixture screws can be left where they for what you're doing they don't have much effect once the motor is running above idle-wouldn't hurt to double check them though.

[yamaha_george]

Thanks for the replies guys, I've gone over it and checked everything I swear. I even took the boots off and inspected them for cracks or holes, and checked the seals on the carbs. I made sure they were seated correctly, and snug. Yg, I did check my cables to see if they were too tight and everything seemed perfect. I bought my bike without the airbox. It came with the dual k&n's and I'm pretty sure it has a jet kit but I'm not sure. One of the jets says factory on it so I'm guessing that's factory pro.

It seems like when I open it up in first and second, sometimes third, it kinda gurgles. I was thinking maybe it was trying to burn up too much fuel? Should I adjust the fuel mixture screws? I'm pretty sure I left them at 3 1/2.

Anyway thanks!

Ng,
Ahaa, Pods, no airbox. Right you need to read my write up in the WIKI (or else on an old Pods post) about mounting the pods properly. Straight onto the carbs is a bitch giving you that condition.

read this and you will understand if not PM me :-

http://fzronline.com/wiki/doku.php?id=pod-tuning

[ng86]

So basically what the wiki is saying, is that I should find some velocity stacks to connect my carbs to my k&n's? Can it really be that simple?