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Throttle issue after exhaust install

5K views 7 replies 4 participants last post by  TurtleSE 
#1 ·
What's up guys?

New to the forum, just picked up an 08 a few weeks ago... getting back into the swing of riding after almost 10 years. I had a 2005 500r in high school and hit some loose gravel, didn't end well.

Anyways, I picked up a Delkevic ss70 slip-on and install went smoothly as it should've... took the bike to work (about 1.5 miles) and noticed a slight dead spot before 3k. On lunch I took it out as I figured it could have been that the bike wasn't at normal operating temp... sure enough on the highway as I twist it seems as though there is a flat spot for a brief amount of time and then it picks up. The issue was there prior to install but I don't think it was this noticeable. I also did not install the baffle, my thoughts point to this as an issue but what do you all think? The bike is stock except for pipe, what are your experiences with not running a baffle? Require jetting/intake mods? Sorry to ramble and sound like a noob, just want to keep her in tip-top shape.

Thanks in advance.
 
#2 ·
baffle or not baffle, it needs to be jetted. It's a carb issue as the carbs are tuned for the stock exhaust. You'll have to jet the carbs, and it may require trying it a couple of different ways until you get it right, but you'll probably never get it perfect as that's just how carbs are.

You risk hurting the carbs and the engine the longer you run it without jetting it. You're most likely going to get worse mileage and less power that way. Jetting isn't too hard, but it's also not too expensive to take it into a mechanic to get it done.



 
#3 ·
Thanks for the reply, I do plan to purchase a jet kit (looking at them now) and having my local Kawasaki dealer do the installation. How high is the risk of damage running it this way? Should I swap back to stock until jetted? I only ride to work and back and the occasional few mile ride... and I rarely take it above 8k. Idk if any of that matters...
 
#4 ·
If you want better overall drivibilty, without a lot of mods, shimming the needles (or installing aftermarket ones) and removing the snorkel works great.

These 10 improvements are easy to do, don't cost a lot and will make the bike respond and ride a little better.

1. Shim the needles with (2) two 3mm washers and remove the snorkel. Shims and a little bit more fuel to the 1/4-3/4 throttle range, a little more fuel results in better throttle response-(simple, don't complicate it)(If you have a slip on exhaust removal of the kleen air system is optional if you don't mind the popping.)

2. Replace the stock air filter with;
WIX- P/N: 49721
UNI Air Filter- P/N: NU-2303
Hurricane Racing Performance Air Filter for the ’08-’12 Ninja 250 or

Pipercross Performance Air Filter- P/N: MXP166 (highly recommended)

4. Leave the airbox in. There is no real need to replace it with pod filters unless you like unnecessary work & spending more time tuning than riding. The exact same or similar results you get with pods you can get with the stock airbox and full exhaust system

3. Install Iridium Spark Plugs-either NGK Iridium CR8EIX or The Denso Iridium IU24.

4. Run 87 octane gas, it makes more power. Use ethanol free if you can get it.

5. Run full synthetic oil

6. Change your sprocket set up to 15/43, it offers the best balance of acceleration and top speed. Any extra HP gains are wasted without the proper gear set up.

Those who ride freeway like to reduce the RPM speed as much as possible and still be able to have passing power in the top gear if need be. As a frequent Hwy rider I use 15/41 and still outpace most traffic easy.

15/41 @ 8k = 76.3 mph in 6th gear
15/42 @ 8k = 74.5 mph in 6th gear
15/43 @ 8k = 72.8 mph in 6th gear
15/44 @ 8k = 71.1 mph in 6th gear
15/45 @ 8k = 69.6 mph in 6th gear


7. If you got a couple hundred dollars, you can change your engine timing. the BRT i-DTIS offers the second most significant gains to HP and torque as far as add ons go. The first is the full exhaust.
 
#7 ·
I spoke with a tech at my local dealership last evening, suggested installing the baffle until I can get the jet kit... He mentioned that in the short term (depending on riding style) that running the bike temporarily will not cause any damage, IF I can deal with the flat spot.

As I pulled into the garage I let the bike idle for a minute or two (habit) and noticed the idle was around 1500, I had it set for roughly 1300+/-... Of course assumed it was due to not running the baffle/exhaust upgrade without proper supporting mods and simply set the idle screw. Apologies if I sound like a smack ass, I know what I need to do and it will be done ASAP. The cruise was an easy one, and only about 20 miles... other than that the bike runs great and I really enjoy being out on the road, nothing like it.

As far as jetting, I ordered the Factory Pro Stage 1 (stock box, filter upgrade/no snorkle) that I found for around $70 and also purchased a Uni filter. I'll keep you all updated, thanks again for pointing me in the right direction and dealing with my paranoia.

-Roc
 
#8 ·
Good choice on the re-jetting! These bikes are all set up for California emissions. Which don't work so well in all regions. Especially higher elevations. My bike is basically stock except for the re-jetting(dynojet kit). Warm up time won't take as long and you will have better throttle response, you may loose some gas mileage but it will be worth it. :2thumbsup
 
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