Fuel efficiency
#1
Fuel efficiency
Hi,
I've been tracking the fuel efficency of my 90 cbr, which I've been riden for about two weeks now. I am getting 25-27 mpg, riding in the city, witbh some highways. I think this is a terrible efficiency, and although I still need to sync the carbs and probably play a bit more with the setup, I am wondering what kind of number do you guys get.
I've been tracking the fuel efficency of my 90 cbr, which I've been riden for about two weeks now. I am getting 25-27 mpg, riding in the city, witbh some highways. I think this is a terrible efficiency, and although I still need to sync the carbs and probably play a bit more with the setup, I am wondering what kind of number do you guys get.
#4
Then, in your oppinion, what could be the major cause of so much fuel consumption? spark plugs are new, I cleanned the carbs and set the pilots 3 1/2 turns. The bike was re-jetted by PO, but I am not sure to which size. It also has a Vance & Hines pipe.
I am planning to eventually do a carb sync and valves adjustment. Do you think any of these two things could be issue, or that is more related to the re-jetting of the carbs?
I am planning to eventually do a carb sync and valves adjustment. Do you think any of these two things could be issue, or that is more related to the re-jetting of the carbs?
#5
Join Date: Aug 2008
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timing, valves & sync ....all 3
Yeah if the jets were changed .....that would impact mpg
Sprocket sizes ????
Stock will give you stock mpg ....... anything else will change it up or down depending
My 90 has an 18/44 on it and if I try hard I can get 48/49 mpg cruising the highway
Yeah if the jets were changed .....that would impact mpg
Sprocket sizes ????
Stock will give you stock mpg ....... anything else will change it up or down depending
My 90 has an 18/44 on it and if I try hard I can get 48/49 mpg cruising the highway
Last edited by Sprock; 04-04-2011 at 10:15 AM.
#6
timing, valves & sync ....all 3
Yeah if the jets were changed .....that would impact mpg
Sprocket sizes ????
Stock will give you stock mpg ....... anything else will change it up or down depending
My 90 has an 18/44 on it and if I try hard I can get 48/49 mpg cruising the highway
Yeah if the jets were changed .....that would impact mpg
Sprocket sizes ????
Stock will give you stock mpg ....... anything else will change it up or down depending
My 90 has an 18/44 on it and if I try hard I can get 48/49 mpg cruising the highway
#7
I am not sure how to check the timing on these bikes, but on a car you check it by connecting a timing light to the #1 spark plug and the light illuminates every time #1 spak plug fires, and you aim the light at the crank case to see if it is aligned with the timing mark on the crank case. It is adjusted by moving the distibuter left and right(advanced and retarded). Now you said that you need to sync your carbs. When you swing by my place one weekend we can do a good bench sync to see if that will help ya. I still havent gotten mine synced yet, but the bench sync and a good cleaning of the carbs helped alot!. I can pull your carbs and check em for ya in no time flat.
Last edited by outlawfox13; 04-04-2011 at 12:07 PM.
#8
I am not sure how to check the timing on these bikes, but on a car you check it by connecting a timing light to the #1 spark plug and the light illuminates every time #1 spak plug fires, and you aim the light at the crank case to see if it is aligned with the timing mark on the crank case. It is adjusted by moving the distibuter left and right(advanced and retarded). Now you said that you need to sync your carbs. When you swing by my place one weekend we can do a good bench sync to see if that will help ya. I still havent gotten mine synced yet, but the bench sync and a good cleaning of the carbs helped alot!. I can pull your carbs and check em for ya in no time flat.
#9
I've got a K&N airfilter, rejetted carbs and a Vance & Hines exhaust. With everything else stock (sprockets , ect) I get between 35 and 38 MPG. I am pretty hard on the throttle and don't seem to get much better mileage. The carb sync helps on power and throtle response but i didn't notice better mileage. Everything listed should be normal maintinance on any new to you bike anyway. you should download the manual Workshop Manuals - CBR Forum - Enthusiast forums for Honda CBR Owners
Last edited by tobiahr; 04-05-2011 at 03:28 AM.
#10
Jajgarica Bench sync only sets the valves to the #3 so they open together at the same time, using a manometer is to get a more accurate adjustment as each carb works slightly different. And no I didnt build one yet, still on the to do list. Doing the valve adjust would have been faster if i didnt throw out my back in the process. I think a good 3-4 hours total from valve adjust to checking your carbs and putting all the fairings back on. But the thing with a valve adjust is that we need to do it on a cold motor. So we would need to add soem time to that if you rode your bike up to my place. It should go faster with you working on the valves while I check your carbs.
Like tobiahr said, doing the sync will only help with throttle response, it may help a lil with mpg, but not much. Might reduce it as you will want to snap the throtle more LOL
Also what does your bike have? Ie exhaust, jets, ect...
Like tobiahr said, doing the sync will only help with throttle response, it may help a lil with mpg, but not much. Might reduce it as you will want to snap the throtle more LOL
Also what does your bike have? Ie exhaust, jets, ect...
Last edited by outlawfox13; 04-05-2011 at 08:43 AM.