Cibbie-1988 CBR 250R
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Most people start on small to medium engined bikes and move up from there. I started out on street bikes with a VF500, then went up to a VFR800, and back DOWN to a CBR 250R. Why? Because I love tiny engines, especially multicylinder engines! I got this bike specifically because of the sound. I saw one video of it and I was hooked.
This is the video that poisoned me. https://www.youtube.com/watch?v=yN2hag8J1rY Having had this bike for at least two years now, I figured I should start a thread for my little screamer to celebrate my first real eco mod to it, taller gearing. Attachment 23255 Attachment 23256 Attachment 23257 Honda says this thing revs to 18.5K. It has been said that they were optimistic and that it only revs to 17.3K. The MC22, which is the newer model with a slightly revised engine appears to rev higher, and it certainly sounds like it too. Attachment 23258 When I first got the bike, it was all stock. The exhaust was of course too quiet, so I put an aftermarket muffler on it. Stock, it would get around 58 mpg with how I ride it now. With the new muffler along with its reduced low end torque brought the gas mileage down to around 54 mpg. I changed the main jets up to 90s instead of 85s when the muffler was installed. The pilot jets were also richened at the time, but I have since adjusted them back to the stock setting. At some point in ownership of the bike it had what seemed like "cylinder deactivation" problems where the bike would start to lose cylinders and power to the point where it could not maintain speed anymore. It eventually turned out to be a fuel supply problem from a kinked hose. However, before that was found out, I thought it was an ignition related problem, so I got a new ECU. The new ECU was advertised as "derestricted", yeah, it was derestricted all right. IT HAS NO REV LIMITER! Normally the bike has a rev limiter at 18.5K rpm indicated, I took the bike up to 20.5K rpm indicated looking for the new rev limiter before deciding continuing to rev higher will only result in destruction. The bike still has that ECU in it, gotta remember to swap back to stock. The pathetic thing is that despite being "derestricted", it still has the 10-14K rpm retarded ignition timing that the stock ECU has. My non O-ring chain recently wore out(Took less than 5K miles! :eek:), so I decided to renew my search for taller sprockets when getting the new chain. This model bike uses a 428 pitch chain, narrowing options significantly. Thankfully, my dad found a 51T rear sprocket off of the 1989-1990 VTR 250, a similar bike in other regards as well. Apparently other parts are shared between these two bikes. Stock gearing is 17T/54T, so a 51T rear sprocket results in 5.5% taller gearing. IIRC the hole setup for the rear sprocket is 6 holes with a 150mm centerline. Here is a gem I found featuring an MC22 and its eargasmic sound. https://www.youtube.com/watch?v=espt...c2JNA&index=39 |
It resembles the Brazilian CBR 450 SR, which had a bigger parallel-twin instead of that 4-cyl due to local content laws. But anyway, even though nowadays I would prefer something less rev-happy and more oriented toward low-end torque, this engine is a marvel of engineering.
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EHEM https://www.youtube.com/watch?v=MBbs...3c2JNA&index=1 The only literbike I would consider getting. |
DAMN....... That sounds Sooo... SWEET
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https://4.bp.blogspot.com/-Oic498QYq...2Bcbr450sr.jpg https://4.bp.blogspot.com/-g4ED0KcpA...2Btraseira.jpg http://2.bp.blogspot.com/-EckAtyv57S.../Photo4456.jpg http://2.bp.blogspot.com/-ozEMWMwgr-.../Photo4454.jpg http://3.bp.blogspot.com/-lRBjZmHAwO.../photo4455.jpg Quote:
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Here is some video, (well, sort of) of MY bike making its sweet music from inside the airbox. Skip to 1:34 if you just want to hear it scream. https://www.youtube.com/watch?v=S0j4...vEdn2OuLWdTeEv |
[QUOTE=Daschicken;557607]Which one? Or is it both? ;) I tend to choose good sounding bikes.
Here is some video, (well, sort of) of MY bike making its sweet music from inside the airbox. Skip to 1:34 if you just want to hear it scream. I like both.....but I'm more partial to my ZRX 1200's :thumbup: Wish I could find one of the ZRX 400 in the states |
Weather cooperated slightly, so I finally got to ride cibbie for a decent amount of time with the new taller rear sprocket. It is so much more pleasant to ride on the highway now, the 500 rpm drop is noticeable and now I don't feel like I have to constantly pulse and glide(which doesn't work very well). Didn't ride long enough to know the fuel economy, so that will have to wait.
I did however put my phone in voice memo mode at the start of the trip to record some nice sounds. It ended up stopping itself after an hour and 25 minutes, but THANKFULLY :thumbup::thumbup::thumbup: it caught me doing a TWENTY THOUSAND RPM pull! Probably last one I will ever do, I need to put the stock ECU back in before I blow this thing up. The recording only had 3 minutes to spare when it caught the pull, I was so happy, I thought I lost it! https://www.youtube.com/watch?v=dkVfaYLSZCY |
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Just weighed cibbie, 346 pounds with a full tank of gas in its current setup(aftermarket exhaust that is lighter than OEM) :thumbup:. I used a medical scale and weighed 1/2 the bike at a time with the unweighed end lifted to about the same height as the weighed end.
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I haven't seen those in a while, but anyway, its looks are basically the same as the 4-banger CBR 250, with only the engine swapped for the 450cc parallel-twin out of the CB due to regional content laws.
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So its been a while since I put the 51T rear sprocket on, but until now I haven't gotten to get a whole tank through it with mostly/just me riding the bike. Even with the taller gearing(or maybe because of it???) my little brother managed to drag a tank down to 43.8 MPG. Absolutely abysmal for a 250cc, and I have beaten that in my V6 Accord!
So I was able to get 57 MPG twice, and then I bumped it up to 59.1 for the last tank! That is not only a new record tank, but it looks like the measly 5.5% taller gearing has brought me back to pre-aftermarket muffler mileage. :D Me and my dad rode to Tennessee and got on Cherohala skyway as well as two passes up and down Deals Gap. Have some action shots! Attachment 23990 Attachment 23991 Here is what my front tire looked like after those gap runs, not a bad chicken strip if I do say so myself. The rear tire had no visible strip. Oh yeah, and I discovered that front tire is 7 years old on this trip. Oops. Time to get a new one. Attachment 23993 There is a difference between SHOULD and CAN. This trucker didn't seem to know that. Attachment 23992 There was a video posted of a miata locking up his brakes and having to steer out of his lane mid BLIND corner to avoid crashing into this jackass. If I find it again, I'll post a link. Anyone who decides to take their big truck/trailer on the gap despite all the warnings should have their CDL immediately revoked. I think we can all agree that truck drivers are the safest drivers on the road, but when you do something as stupid as this, all that goes out the window. You can easily get someone killed driving just a few miles on a road like this in a truck like that. And a nice sunset picture to finish off my post. Our cabin had a steep gravel road leading up to it, which made things interesting. Having previous experience with dirt bikes comes in handy at times like that. Attachment 23994 |
I finally synced the carbs on cibbie, it was not that bad(the procedure, not the synchronization) actually. I probably would have done it earlier if the carb synchronizer wasn't hiding for 3 years... They were a good bit off, as you will see in this video. Cylinder 1 appears to be making boost under certain conditions! :p (probably due to the excessive valve overlap needed for a screamer) No word on gas mileage yet, still have to ride it. The idle is much more stable now, and it will likely drop to idle right away when I pull in the clutch to coast. It usually hangs around 3000 RPM for around 10 seconds, and then drops to idle.
https://www.youtube.com/watch?v=x5oKhy-lbbE Oh yeah, it was really cool to have four vacuum gauges on the bike, so the next mod will likely be a vacuum gauge, if I can find a nipple valve that will fit it. I could probably order one from the Australian wreckers at the same time I could also order a front fender from the earlier CBR 250. |
Worn 7 year old tire no longer on the front. :thumbup: I now have matching Bridgestone S20 Evos front and rear. The front wheel spins pretty good without the brake caliper on it, maybe time for some brake return springs?
I did find a source for taller than 51T rear sprockets for my CBR 250R. They offer blanks as well. Next time I need a chain I will probably go for a 49T rear, or even taller. I did finally take the plunge and buy some paraffin wax and equipment for waxing chains. I put the pot of wax into a larger pot of water and heated that over a burner to avoid getting too hot. Who needs wax heaters? So, now that I am using wax, my chain should stay much cleaner for longer, and stay better lubricated too. That chain replacement may not be needed for a while. https://shop.pbisprockets.com/produc...&categoryId=13 Front fender from an MC14 ordered on a Japanese auction site. Hopefully will get it within a month. |
I broke 60 MPG for the first time with my little screamer, I also broke something else...My speedo cable decided it didn't want to stay attached anymore at the start of today's ride. I believe on later models of the MC19 and all(?) MC22s if the speedo cable is not connected, the engine is limited to either 8000 or 12000 RPM. Either way, mine didn't do anything unusual. I was able to get a trip reading from using google maps distance as well as the trip meter reading from my vfr 400.
Lots of chooching and sudden braking, but that didn't stop me from beating 60! 65 Should be well within reach, 70 might take some more effort though. My aero front fender should be showing up this coming week, and I may work on some brake drag reduction springs. 134.8 miles with 2.236 gallons = 60.3 MPG! |
Spotted this CBR250RR at Road America this weekend -
https://i.imgur.com/fGaYDtu.jpg?1 Neat bike. Wish they were available here. He says it's a blast to ride. His family also brought these 2 - https://i.imgur.com/qg0ypwH.jpg?1 NSR250 and Mach III |
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Very nice. My family has its share of grey import bikes ;). They really aren't that hard to import, and they don't cost all that much either. My CBR 250R cost $3000 CAN, which was around $2500 US at the time, and my VFR 400R cost only $2000 CAN. With you being in Wisconsin, you are much closer to the action than I am down in Georgia. Its pretty much just verify they are 25+ years old or on the import exemption list, buy it, and bring it to the border. I don't think we were charged an import fee for any of the bikes. We were usually through within an hour, and for latest bike we imported, the lady doing the paperwork didn't even bother to walk outside and look at it! So cold weather and/or dark outside increases your chances of the import people not looking at it. The peace bridge in New York has been pretty easy on imports, but the crossing in Detroit is not so easy apparently. I don't remember which crossings we used. Once the bike is in, you get a police officer to finish up some import paperwork and verify the bike isn't stolen, then it is pretty much good to go. Insurance is a little iffy, since the insurance companies have a hard time trying to enter the shorter Japanese VIN. I am still looking for a 250RR, not so much lately since I got the VFR 400 and the CBR runs so good. I do know that in 15 years, I will be importing a bunch of bikes, starting with the varadero 125. |
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Front fender from an MC14(CBR 250 Four) showed up. A huge improvement over the bikini fender that comes stock on my bike, unfortunately it doesn't look so hot. Whatever coloration that is on that fender seems to be embedded into the paint. It still feels smooth, and I can't wash it off. :confused:
EIGHT DOLL-HAIRS http://ecomodder.com/forum/attachmen...3&d=1528865117 I also ordered an oil pan heater for the CBR, due to its limited flat space I got the 1"x5" 25 watt pad. This will be more for longevity than for fuel economy, but it should help both. http://ecomodder.com/forum/attachmen...4&d=1528865125 |
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Just an update, front fender is still away and the little heater would not fit anywhere that would be useful. I have been looking into installing a vacuum gauge on the bike to aid in efficient acceleration and DWL. It took some asking around on the four cylinder specific forum, but I did find and order the part I needed, a 6mm hose barb.
https://ecomodder.com/forum/attachme...7&d=1535583896 Update update: I found a 1"x1" square heater pad, will check dimensions on little cibbie's oil pan again and see if I can fit that somewhere. The other heater I bought was 1"x5". |
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I found the gauge needle bounced around too much to be read (because it's only picking up one cylinder I suppose). Adding a flow controller (one way) to the line steadied the needle, but it probably messed with it's accuracy. As far as usability goes, I found little difference between part throttle and WOT in normal riding, so it didn't really help. Maybe the CBR's higher revs will help? With it's modified gearing, my VT (probably) seldom goes over 7500 rpm (no tacho). |
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Maybe the lack of excess power on your VT had something to do with the small changes in needle movement? Actually, my CBR only has 5 more horsepower, so maybe not. I will find out soon enough! Also, there is an entry for a 1988 VT250C on gearingcommander.com, punch in your shift point mph and find out your rpms! |
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Thanks for the gearingcommander tip. It tells me The VT is turning under 6300rpm at 110kph on the Motorway. |
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ZUCCess!
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My 1"x1" heater FINALLY showed up(partly my fault), and it looks like I could have gone bigger. The heater is only 10 watts, so I didn't expect much, but it does in fact work, and I did measure higher oil pan temps. I'll have to leave it plugged in for 2 hours and see what kind of oil temps it gets up to. I had it on for maybe half an hour, and saw oil pan temps climb about 6 degrees F. Temperature on the heater itself didn't go much over 200 degrees F.
https://ecomodder.com/forum/attachme...9&d=1537497301 https://ecomodder.com/forum/attachme...0&d=1537497310 Vacuum gauge is hooked up and sourcing vacuum from cylinders 1 and 4. Haven't gotten to ride it since that first test ride with 1 cylinder tapped cause I was fixing a coolant leak. The leak is fixed now, I just have to go get more coolant! |
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Oil pan heater is now wired in with a quick disconnect plug. :thumbup:
https://ecomodder.com/forum/attachme...6&d=1538282186 I have since ridden the bike with the vacuum gauge sourcing vacuum from cylinders 1 and 4. Idle is hopeless, but once the bike is actually moving the needle steadies out and doesn't wiggle at all. The gauge is also mounted to the bike now, but its kind of ghetto and is hard to see unless I position myself correctly. As D.O.G. pointed out, there isn't much difference between full throttle and other throttle positions while accelerating. I can easily drop to 0.5 In Hg(?) or below when accelerating. When cruising however, the gauge does become useful, and the needle climbs up to around 4-8 In Hg(?). I believe off throttle was around 11. So far I have run two tanks through with the vacuum gauge installed, but I also adopted a new less accurate fillup technique to avoid fuel overflowing out of the cap when riding. Both fillups were at or above 60 MPG, so I have high hopes for this mod. |
Where did you get that oil pan heater from? I haven't been able to find any smaller than the 1x5 you got before. I think I will pick up 1 or 2 for my bike
Thanks, Matt |
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It was also $50...so...ouch. |
I was just on their website and saw some band heaters, what do you think about putting it on my oil filter? I don't know what kind of filter your bike(s) have, but mine has a "regular" car type oil filter. Unlike my old bike which uses the cartridge style filter.
(https://www.oemheaters.com/category/...meters-up-to-3) |
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