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yoshimura r77 slip on hunting idle issues

5K views 17 replies 6 participants last post by  Larry Allen 
#1 ·
2015 cbr100rr

r77 3/4 system

bike has pc5 with r77 slip-on map

hunts at idle surging from 1200-1800 rpm

tried adding more fuel on idle still doing it

any options?

i figured the power commander would fix this but no go ..

don't have dyno where i live and its a not a option to get to one

options?
 
#5 ·
i sold the yoshimura , i have a sc project on the way ..
honestly sick of the surging .. i tried bumping it up it helped at times but like you said sometimes its fine sometimes it surging .. if I'm in slow traffic its almost like its lunging.. not the way i like my bikes.. never had this issue with my ninja zx10r.. with any exhaust

hopefully the sc project wont be like this ..
next step for me is a ecu tune.. or a auto tune with the power commander
 
#6 ·
Our ECU flash can correct this common problem which sometimes occurs when you install an aftermarket exhaust.We will adjust the idle speed, ignition timing and the fuel curve when we flash these models and get rid of the idle surging problems.We actually offer a package for the CBR1000RR which includes a Yoshimura R-77 exhaust, smog plates and ECU flash for $935.00.We have the perfect tune for this combination: http://www.danosperformance.com/Specials.htm Thanks Dan
 
#9 ·
I have R77 on mine and had the same problem. I have a Bazzaz FI on mine and tried the same solution as everyone said, add fuel. Sure you add enough fuel (drowned it) and ya the idle will settle down but when my data logger says the afr is at 13.2 at ide , it's a stupid solution. I hooked up vacuum lines to each cylinder to see if they were different from the factory and yeah they were. Probably set that way for the stock exhaust so it would idle nice and even but when you switch cans well you made a change.. Everyone also said there is no air screws to adjust the vacuum well yeah there are. Makes sense that factory has to be adjust each bike no bike is the same right. Pull the air box off looked at the manifold and guess what I saw each cylinder has a black air screw, what you know. I adjusted them and set the vacuum for each cylinder and the surging is and has been gone with a fuel ratio 14.3 idle real nice and clean. Pull up to stop and idle is fine and no smell of rich unburned gas. Wrote up my procedure a while back so its out there. Good luck with our new pipe hopefully it works for you.
 
#10 ·
Sounds like a lot of works! I'm just curious if I did add a power commander or tune my bike so at idle I have a higher fuel ratio like yours would that solve the problem? I quite don't understand the way you did by adjusting it manually you pretty much change up the ratio like tuning would correct?

@skeleton
I do not have a sensor on the bike.

I'm going to see if this the problem with the bike by starting it up and putting a blockage on 1/3 of the exhaust to see if it stop the surging if it does than I can confirm it is the pipe itself.
 
#14 ·
No your missing it. My point is that the surging (at least on my bike I have to say that) was caused by the throttle bodies being out of sync due to the new R77 vs stock can which is restrictive. Most guys and I guess some tuners will just throw more fuel at it at idle to correct it, but more fuel is just a bandaid, the real problem is the throttle bodies now being out of sync. If you take the time to sync the throttle bodies which you can do, then it is possible to get a good idle at a decent afr for example 14.3. So the easy bandaid way is just keep adding fuel, of coarse how to add and which cylinder or cylinders actually need it , well you will be guessing. The right way and yes takes more time but for me is way worth it, is to sync the the throttle bodies. Hope this clarifies.
 
#16 ·
Carbstix something like that. It allows you to connect to all four. I stayed away from gauges because they bounce to much. When I did mine I found that cyl 2 and 3 were close to each other as far as vacuum (hg) so their numbers were what I used as my base number to get 1 and 4 equal to. It may take a couple of tries just follow my notes and write down (diagrams) of the positions of the screws before you start so you get back to the starting position if needed. When you start write done how much of a turn you make or even better draw a picture that way you know how far and what direction you turned the screw. It will be a pain because every time you will have remove the airbox to make a change , then check it with gauge. You are going to want to use the values when at operating temperature 170 - 180 degrees. When it gets hot you will have to stop , let it cool , make an adjustment and try again. Turing the screw clockwise will cause the the values to rise since you are reducing the amount of air hence increasing the vacuum. Do it on a day when it's raining so your not wasting riding, worked for me. My first adjustment I started with was 3/4 of turn clockwise on cyl #1 and a half a turn clockwise with cyl #4 based on the reading I got, then went from there.
 
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