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Discussion Starter · #1 ·
My KLR650 is giving me trouble...

My bike has no airbox, I removed it and replaced it with a standard uni pod air filter. It worked fine with the stock carb settings and stock pipe.

I bought a new exhaust and was told i needed a jet kit because of the increased airflow. Dynojet suggested stage 2 because I dont use the airbox.

So I installed a stage 2 Dyno jet Kit into my Keihin CVK 40, which included drilling out the vacuum hole and then installing a different main jet and needle.

I did everything to spec and when I tested out the bike on the streets it worked fine.

This morning I took it out on its maiden voyage on the freeway and about 10 minutes into the ride at the top of 5th it started to bog down? where it kept instantly losing and gaining power as if it was running out of gas (i put a fresh tank in this morning).

So what is going on here? what do i need to adjust? this bike is a big learning process and is there a way to test out if the bike will run at higher rpms that doesn't involve me being on the freeway, it was fucking scary hahaha.

thanks,

-Z
 

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my 1200 bandit will do this to me every once in a while and i can't figure it out it will run fine for months then one day i get the same thing you just described i'll pull in the clutch and rev it up a few times and it clears rite up. did you try to do that? if so did it change anything?

I know that really doesn't help you at all but I will be checking in to see if you get a good answer somebody out there has to have an idea
 

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Can you replicate the symptom at a lower speed? CV carbs are easier to troubleshoot by relating when those symptoms occur in relation to throttle twist (closed, 1/4, 1/2, 3/4, WOT). I'm guessing by your description, high speed, high gear, highway speeds, the issue is closer to WOT. Does it happen at WOT in a lower gear? If not, and its only at high speeds, then it could be caused by the change in the air box/pod filter. The engine may be having trouble drawing in the air it needs as its rushing passed the filter.

Hope this helps.
 

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Its surging from running lean on the top end try turn the pilot screw in a 1/2 turn. I had this problem on a ex250 after I rebuilt the carbs. Easy fix its all in tuning.

Good luck
 

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Discussion Starter · #6 ·
I could get it to do the same thing when I was in the top of third and went over 4500 rpms. If its running lean, then I am getting too much air, which was the first problem I had to solve when I removed the airbox but was still using the stock jets and pipe.
 

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Discussion Starter · #8 ·
But it only does it at highway speeds since you've rejetted?
Yes only High Speeds. I turned out the air/mixture screw to about 2 3/4 turns (recommended is 2.5 turns) and it seems a little better but I wasn't able to get it up passed 55 on the bakc roads I was testing on. Its raining today, if its dry tomorrow I will try the bike on the highway and see if it does it at 60+ miles an hour.
 

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Yeah, I've been fighting the same issue with my ex250 airbox delete. I'm far from an engineer, but I've read and learned that the stock boxes are there to keep a reserve of static air on hand for the engine to suck in as needed. Without the static air, the pods are trying to suck in air as its passing by at 50+ mph. I've thot of making a fiberglass "shell" to put around my oval filter, to help direct the air into it, kind of like ram air induction lite. Also using U-shaped tubing in the same manner. Even mounting some cones or tubes inside the filter and using the filter itself as the airbox, and those tubes to replicate the original inlets, in hopes of getting a more concentrated flow into the carbs. These things always get finicky when trying to run them out of their designed purpose, but that's pretty much why we're all here. Good luck, and keep us posted with updates or any solutions you come across. We're all here to help each other! :knucks:
 

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Discussion Starter · #10 ·
Ok so I have more odd symptoms:

When I shift up and rev into the throttle quickly after shifting and disengaging the clutch, I will generally get a back fire from the pipe.
When I pull the clutch in to coast and shift down while coming to a stop (sometimes, not all the time) the engine will die.
I am still getting the sudden loss and regain of power (like an off/on/off/on/off etc lurching feeling as if it is hunting for gas) when I either rev up to a high rpm (4500+) or I am in 5th gear at 65+

Does this sound like I am running to rich or lean? Fuck this is confusing, Ive tried adjustments in both directions. Im going to take it apart again and check everything and also check the spark plugs for soot.
 
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