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I took out the snorkel for about a week but put it back.
My bike is 100% stock engine wise,it gives you a bit more power above 9000rpm but you loose a lot between 6-7000rpm.
With it in power is completely over by 9000rpm,removed it will go to 9500rpm,10000 at a push.
Starting and tick over same as stock.
 

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I took out the snorkel for about a week but put it back.
My bike is 100% stock engine wise,it gives you a bit more power above 9000rpm but you loose a lot between 6-7000rpm.
With it in power is completely over by 9000rpm,removed it will go to 9500rpm,10000 at a push.
Starting and tick over same as stock.
that might work well for people with an ejk, where fuelling may correct the drop you found?
 
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it has been mentioned before on our Forum not to remove the snorkel from the air box because it causes turbulence. I believe it was mikal who mentioned it.
 

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I've removed my snorkel and the air filter access lid and just put on a slip on muffler. Only had this bike for a week and my top speed section on the way to work completely stock got 98 mph indicated on a slight down slope. I'm going to run it all week into work and see if I can get 100 mph indicated.
 

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These days with better airbox design the stock set up is often best. Drilling holes and removing lids can be a backwards step, esp if you are not re-mapping the fuel tables to suit afterwards. More common is to fit a high flow filter and re-map.

Do a run and then refit the bits you've removed and see if it changes your top speed. But its probably more your low - midrange power that the mods (potentially) could be having a detrimental effect on. See post #2 above. After all, you dont ride around at top speed everywhere.
 

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Did not have the open lanes for my downslope 98 mph section. On return home had a straight and level with open lanes and full throttle for a long stretch got up to 95 mph indicated with straight pipe, air box cover removed, snorkel removed and stock air filter. Regardless, my bike is not a 100 mph bike at this point.
 

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I got a genuine (GPS'd) 100mph out of mine with stock air box and filter. Aftermarket slip on was only engine mod.
 
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This week I still have Tues, Wed. and Thurs. to get that comparison run and try to up the 98 mph indicated. I'm going to leave it with the airbox mods for the rest of the week. Additionally, two tanks full of gas averaging 67 mpg with zero regard for maximum mpg. The cbr300r is for me the best ride for now.

I had a Ninja 300 (111 mph on the same comparison run, only once did it reach that speed, it'd hit 105 indicated most days) and I had a Ninja 400 (would hit 111 mph indicated anywhere pretty much, top speed was not a thing to test with that bike on the Los Angeles freeways it was that fast) and I had an R3 (maxed at 113 mph once on a much steeper and longer down slope. Neither the Ninja 300 or the R3 I had were 110mph bikes straight and level, no way.

My opinion, the cbr300r is the best street bike of them small "beginner bike" twins/singles for looks, abs braking, handling, and everyday performance. I have five other bikes that will go faster but my other bikes don't have abs, don't have the undeniable reliability of a 2k mile Honda, don't have running lights, don't have the ease of handling, don't have the ease of control, and don't have the silky smooth transmission lol !!!
 

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Thanks for the back story, I thought your username was familiar! I remember you from the Ninja 400 site.
Yeah the Ninjas are great bikes but I probably had the most fun on my two CBR's, you can really flick them around. I should have upgraded the suspension on my 300 considering the type of riding i was doing. I'm kinda on the lookout for a cheap CB300R that I can turn into an ultra light fun bike. They're lighter than the CBR's and have the better front end on them.
Getting back to top speeds... Best I got out of the Ninja was a genuine 119mph but the optimistic clock was reading 125mph. This was after I fitted an aftermarket pipe though and flashed the ECU to match. That mod gave me another 7kph (4.3mph) top speed. Stock air filter.
 

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Reached 100mph indicated, different section than 98mph run. It was longer and less of a down slope. I dont think the air filter access lid and snorkel removal hinder max rpm performance. No power dips noticeable anywhere in the rev range.

Didn't hit rev limiter at 100mph, there are couple more mph reachable. Totally content to have 100mph capable 286cc single!
 

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And hit 100mph indicated with the stock paper air filter (with snorkel and air box cover removed and straight pipe) on the same section of the previous, all stock 98mph run. My conclusion, only 3 data points I know, is that the air box mods and straight pipe do not hinder reaching maximum rpm. Can't really conclude that they help either.
 
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