Poor MPG and Throttle Hesitation - Page 3 - Honda CBR250R Forum : Honda CBR 250 Forums
User Tag List

 19Likes
Reply
 
LinkBack Thread Tools
post #21 of 38 Old 07-21-2017, 11:37 AM
Senior Member
 
sendler's Avatar
 
Join Date: May 2011
Location: Syracuse, NY USA
Posts: 3,527
Thanks: 89
Thanked 447 Times in 307 Posts
Quote:
Originally Posted by jkv357 View Post
What is the explanation for carbon build-up, engine meltdown, burned valves, scored cylinders, etc, especially when ridden gently then?

I can't see how running a strong fuel system cleaner can be blamed for numerous tanks of poor fuel economy.

Try Techron next time (if there is a next time).
What is the explanation for my non engine meltdown?
.
The only engine meltdowns I've seen on here happened shortly after botched valve adjustments that nobody wants to admit to. Or running engine mods such as complete exhaust systems with a poor fuel mixture retune.
.
Fuel cleaner has no/ poor energy density compared to actual fuel and I don't run my tank dry every time so it took a few fill ups to get rid of it all.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
sendler is offline  
Sponsored Links
Advertisement
 
post #22 of 38 Old 07-21-2017, 11:44 AM Thread Starter
Senior Member
 
TrueFaith's Avatar
 
Join Date: Apr 2011
Location: Brookfield, MA
Posts: 1,301
Thanks: 69
Thanked 438 Times in 281 Posts
Quote:
Originally Posted by sendler View Post
Any recent mods or service work. Valve adjustment?
I used a small amount of fuel additive once and it decreased my fuel economy for three tanks. Never again.
Last mod was installing a Delkevic slip on last fall, but I have quite a few trouble-free miles on the bike since then and have only recently noticed the issues, which came on quite suddenly and were immediately noticeable.
And I was having the hesitation and increase in gas consumption for at least a couple of weeks before I added any additive to the gas.
The fact that it hasn't made any difference at all so far is what's leading me to think it might be some kind of sensor problem, like the O2 sensor or the throttle position sensor rather than a fuel issue.
If I run more B-12 through it this weekend with still no noticeable change, I'll pull and check the spark plug and start turning my attention to the myriad of mechanical possibilities that could be causing it, but I'm hoping I just haven't run ENOUGH B-12 through the injectors yet and it's just stubborn deposits of some kind.
TrueFaith is offline  
post #23 of 38 Old 07-21-2017, 12:02 PM
Senior Member
 
Join Date: Sep 2011
Location: WI
Posts: 1,725
Thanks: 246
Thanked 258 Times in 197 Posts
Quote:
Originally Posted by sendler View Post
What is the explanation for my non engine meltdown?
.
The only engine meltdowns I've seen on here happened shortly after botched valve adjustments that nobody wants to admit to. Or running engine mods such as complete exhaust systems with a poor fuel mixture retune.
.
Fuel cleaner has no/ poor energy density compared to actual fuel and I don't run my tank dry every time so it took a few fill ups to get rid of it all.
Not sure about your good fortune, but there are more than a few instances here where there was some type of unexplained meltdown. Carbon build-up and burned valves have been found upon disassembly.

At a 128:1 ration (1oz per gal) I can't see it taking 3 tanks to clear the system. If you really want the full benefit - run the entire tank without diluting it.

You do what works for you, but I can't see the downside to removing deposits from the intake valves and combustion chamber once per season with a strong fuel system cleaner like Techron Concentrate.
jkv357 is online now  
 
post #24 of 38 Old 07-21-2017, 12:12 PM Thread Starter
Senior Member
 
TrueFaith's Avatar
 
Join Date: Apr 2011
Location: Brookfield, MA
Posts: 1,301
Thanks: 69
Thanked 438 Times in 281 Posts
Quote:
Originally Posted by jkv357 View Post
Depending on how you ride, running a strong fuel system cleaner in the CBR may prevent some serious issues.

The CBR appears to have unusual engine problems when ridden lightly and not revved. Deposits build-up in the combustion chamber and intake valves and lead to detonation, burned valves, and engine damage.

None of this has been proven absolutely, but everything I've encountered here over the last few years suggests that deposits could be the cause.

I can't say I've ever noticed any mileage drop from running Techron, but it could be possible. Not sure how it could continue after the treated gas had been consumed though.
You could be onto something there jkv357. For the first few years of ownership I was anything but aggressive with the RPMs. As I've become more familiar with the bike over time I've been pushing the engine a lot more and spending most of my time up in the "sweet spot" from 8000RPM to just short of redline. It could be that years of deposit build-up are only now becoming noticed because I'm wringing the engine out a lot more in all gears. Perhaps the hesitation has been present for a while now and I was mistaking it for lugging at lower RPMs.
If that's the case it may take more than a couple of tanks of treated gas to eliminate it all.
I don't think the unusual increase in gas consumption can be blamed entirely on riding more aggressively in higher RPMs though. It's so pronounced and noticeable from the good mileage I've always had that something else must be the cause.
My valves were well within spec at the 600 mile check and the bike has been absolutely trouble-free since I drove it home from the dealer, so this sudden onset of weirdness is a real head-scratcher.
TrueFaith is offline  
post #25 of 38 Old 07-21-2017, 12:15 PM
Senior Member
 
sendler's Avatar
 
Join Date: May 2011
Location: Syracuse, NY USA
Posts: 3,527
Thanks: 89
Thanked 447 Times in 307 Posts
Quote:
Originally Posted by jkv357 View Post
Not sure about your good fortune, but there are more than a few instances here where there was some type of unexplained meltdown. Carbon build-up and burned valves have been found upon disassembly.
Incorrect valve measurement and adjustment left them way too tight. This engine is very tricky even for Honda dealer techs that don't see them often or are doing their first one because of the fingers that reach down inside of the bucket to the shim.
.
We also see a vast number of users running aftermarket exhausts with no dyno tune that have no idea how far off the map they are.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
sendler is offline  
post #26 of 38 Old 07-22-2017, 01:27 AM
Senior Member
 
Join Date: Jan 2012
Location: Piedmont, NC
Posts: 1,872
Thanks: 140
Thanked 490 Times in 380 Posts
I can attest that general light riding does not harm these bikes, as long as they aren't lugged. I generally accelerate/shift/cruise in the 4-5k range, and my bike is trouble free. I also have a slip-on exhaust without a fuel controller and have had no issues. My pistons and valves are squeaky clean (I also run 2 ounces of B12 through a full tank every 3k miles or so), I consume no oil, and my valves are always in spec. I will also say that the occasional spirited ride is good for the bike and the soul.

But, if a noticeable drop in mileage is seen as a direct result of a fuel additive, either the additive was total crap, or you added way too much. So much you diluted the fuel and are now reducing your combustable power. (an ounce or two of less explosive cleaner in 2.5-3 gallons is hardly noticeable)
shisoshin likes this.

Tis better to be thought a fool and remain silent, than to open one's mouth and remove all doubt.
cbrlocal is offline  
post #27 of 38 Old 07-22-2017, 06:23 AM
Senior Member
 
Schroeder's Avatar
 
Join Date: Mar 2014
Location: Germany
Posts: 1,815
Thanks: 206
Thanked 356 Times in 293 Posts
^I can confirm the above. My bike never sees the rev limiter and I also shift as early as possible in city traffic and so far no problems with the bike in 33,000km (apart from the spark plug and I still think changing it was unnecessary and they ripped me off with that...). Over here people very rarely use fuel cleaners (actually I had never even heard of that stuff before joining this forum) and it's generally considered to be useless and more of a money grab than anything. However we might have different fuel and a different climate here.

My computer is fighting Aids and Cancer in it's idle time, and yours?
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Schroeder is offline  
post #28 of 38 Old 07-22-2017, 11:28 AM Thread Starter
Senior Member
 
TrueFaith's Avatar
 
Join Date: Apr 2011
Location: Brookfield, MA
Posts: 1,301
Thanks: 69
Thanked 438 Times in 281 Posts
Well, I think a lot of new owners pamper their bikes way too much if this forum is any indication. I'd never heard of Seafoam before joining this forum and the frequent debates about regular gas vs premium in a bike that's clearly designed to use regular gas have always perplexed me. It also constantly amazes me how many people with brand new bikes are chomping at the bit to add numerous performance "mods" before they've even logged their first 1000 miles. I mean jeez, if you wanted the performance of a 650cc motorcycle why didn't you just buy one in the first place?
My previous bike was a Ninja250R that was purchased after a laundry list of performance mods were done to it by a local gearhead who was basically attempting to wring every last ounce of performance out of it's 250cc twin cylinder engine possible, he spent hundreds of dollars on pod filters, full exhaust replacement, carb refinements and dyno tuning after every mod performed. While it was quite the little screamer of a bike, I found that all those mods increased maintenance duties tenfold and only made any small variation in performance a cause for concern. The darn thing was just too much work to maintain for it's comparatively small increase in overall performance.
The CBR250R, on the other hand, has always struck me as a bike that was designed about as well as a 250 could be from the get-go. I vowed to keep things as stock as possible and not succumb to trying to make it something it's not. It's about as "bulletproof" and maintenence-free as a small displacement bike can be. From day one it has met or exceeded my expectations and perfectly suits my riding style much better than the heavily modded Ninja250R that was trying to be something it wasn't really designed to be. After a particularly close call with an errant deer in the road that left me with deer snot on my jacket sleeve (it was REALLY close) I added a louder slip-on exhaust to help announce my presence to the animal world, but that's been the extent of my mods to the bike.
It's been so incredibly reliable and predictable since I purchased it in 2011 that this sudden onset of something being a bit "off" in the throttle response and MPG was instantly noticeable, but it also leads me to believe that once it's found the cause will be inexpensive and simple to rectify. Still hoping it's just a case of allowing the additive to work fully, but I certainly appreciate all your input on the matter. Joining this forum was the second best decision I've made after dumping the Ninja and buying my CBR250R.
shisoshin likes this.
TrueFaith is offline  
post #29 of 38 Old 07-22-2017, 08:39 PM
Senior Member
 
Join Date: Feb 2012
Location: coogee beach australia
Posts: 3,226
Thanks: 976
Thanked 1,328 Times in 832 Posts
ive also never used fuel additives/cleaners etc
[7 road hondas] which all ran 'perfectly'..
then again all were ridden year-round..

cbr250r/cbr300r's ethanol free 91ron [86pon]..
with or without lv carbon slip-ons

all enjoyed a good clean out occasionally
once warmed up, thru gears to high revs
then back down engine braking..
motorcycles are made for the road,
not just, putting along with the cars..
these hondas have 10krpm + rev limiters,
meaning a designed in expectation to use
carefully selected gear ratios with available revs..

the 'middle way' works here..
riding sensibly according to conditions etc,
but including the occasional strong 'clean out'..
for riders natural secretion of adrenaline,
endorphins and dopamine can/should be
another addition to riding pleasure,,
not an excuse for addiction..
[to each their own, or course]
TrueFaith likes this.
shisoshin is offline  
post #30 of 38 Old 07-26-2017, 07:33 PM Thread Starter
Senior Member
 
TrueFaith's Avatar
 
Join Date: Apr 2011
Location: Brookfield, MA
Posts: 1,301
Thanks: 69
Thanked 438 Times in 281 Posts
I think I'm finally starting to see some results from the fuel treatment. The weather has been abysmal here the last 3 days, with rain and temps only in the 50s, but today was more seasonable and I was able to take the bike out for a "spirited" 3-hour ride. By the end of the ride I was starting to notice a lessening of the hesitation in all gears, but I still seem to have flat spots in the throttle response at certain RPMs. Mostly 5000 to 7000, but it's definitely improved at higher revs.
My mileage has dramatically improved. I barely lost a bar on the gas gauge in an hour of hard riding, so gas usage seems to be returning to something much closer to normal.
Almost time for another fill-up, so perhaps a 3rd treated tank of gas (I think I'll throw in some Techron this time) will be all that's needed to clean out any deposits that remain. Keeping my fingers crossed.
TrueFaith is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda CBR250R Forum : Honda CBR 250 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome