I think there is a pin you need to swap on the main harness to get the speedo to function, I don't know which one though, I read it somewhere like months ago, maybe on thumpertalk? Has anyone done a 0-60 test run with a 300 rally?
Today by chance I happened to check 0-60: mine seemed to take about 10 seconds but I was not going extremely hard on it. 14-40 gearing. Recently I picked up a CRF250L Rally that already had tons of mods including a CBR300R engine + ECU, Ohlins shock + fork mods, FMF Q4 with Megabomb header etc. Previous owner had some of the stock parts so I put the original stock header and exhaust back on because that FMF is just way too loud. Comparing to another person's stock '13 250L this one still has a lot more guts. Not a fan of the transmission ratios compared to the stock 250 though. Both bike and the swapped engine have around 1500 miles. SpeedoDRD fixed speedometer. Having a few issues that are concerning me: 1. Engine seems to run hot. With the CBR swap it lost the high temp light. On an 80 degree day seems to stabilize around 175 degrees once warmed up for regular street riding but mild off-road riding it goes into the low 200s in just a few minutes. Fan works. Honda coolant. What temps are others getting? I'm nervous it will not stay cool enough when riding out west in the desert. 2. The CBR300R engine seems "rattly" comparing to a stock 250. Some searching I read of what is called the "CBR 5000rpm rattle" most likely due to cam chain tensioner going out. Replaced with a Krieger manual tensioner and adjusted by feel/sound per the instructions. Rattle is a little better but still there on occasion. Intermittent - seems to happen most on quick decelerations, chugging around off pavement, etc. Anyone else experience this? Kinda has me scared... may take the head off to see if the cams are toast but want to get some input first as to whether I should worry or just ride it. Maybe that is just how these CBRs run? 3. It was geared 14-42 but had to be flogged at 7500rpm to go 55mph. Changing to 14-40 was a little better, about 60-65mph around 7500rpm. Still feels like I am flogging the poor little thing above 60, 55 is manageable now. Is 14-39 or 15-40 going too far? 4. Swapped the pin to get the tach going but the reading is intermittent - seems to be vibration related. Anyone know of a source for replacement contacts for the ECU plugs? Any help or suggestions would be great. I like the platform - good little ultralight 50/50 adventure bike but need to make sure what I have is ok before panic searching for something else for a trip out west in the Rockies this summer and maybe Utah in the fall.
I have run 15/40 and now 14/38 on my Crf300rally. Makes the speedo much more accurate and cuts rpm by about 400 at highway speed... it feels a lot less stressed.
Why is my 2013?CRF300L so slow and getting such low fuel mileage...? URG, this bike has had a black cloud over it since I bought it!! I bought it November 2017 and I had my first real ride on it only a month ago!! Turns out the PO ran the motor low on oil so when I test road it, it started fine and it road fine around the small town I bought it from (ie: no Hwy speeds and the engine really didn’t get warm). So last year after a few other issues I finally had it out in the road and once the engine heated up the rear wheel locked up at 50 miles/hr!!! So I sent an oil sample away and there was non-ferrous metal bits in it and the oil was a moly grey colour. I got the bike to a mechanic, he cracked the case open and found the seize cylinder, the motor was pooched So I bought a 2016 CB300f with 3000 miles on it. My buddy (who lives 3 hours away) transplanted it into the CRF frame about 2 months ago. On the test ride all went well. I came down to his place and we did a day ride, all seemed good but I expected more power from the 300, but I never rode the 250 so I had nothing to compare it to. 3 weeks later we planned an overnight trip. We didn’t get more than 150 miles away and my after market fuel tank started to leak from the fuel pump (again). I adjusted the mounting bolts but all that did was cause the fuel to pour out, so all I could do was pull it to the gravel and wait for it to finish draining the full tank, while I waited for the tow truck to take me 150 miles back to my buddies house. So fast forward a month and I mounted my new Acerbis tank AND NO LEAKS!! So tonight I did a HWY test ride to check top speed and fuel mileage. Very disappointing results..... My top speed (gps corrected) was 70.6 miles/hour and my fuel mileage was 42 miles/gallon!!!!!! (using an American gallon). My Speedo is only 3 miles/hr to high based on the GPS. I went over the truck scales and just the bike weighed 374 pounds with a full 12.5 litre tank. I’m running a 14t up front and a stock 42t on the rear. The bike only has 1600 miles on it and the CB300 engine has ~3000 miles. So what the Frick is going on? The one thing I noticed when I look into the clear tank I can see bubbles coming out of the bottom of the fuel tank. When I was installing the first aftermarket tank I noticed the same bubbles thing, but I thought it was because the pump fell onto the cement garage floor as I was installing the new tank. Jeez!! So I bought another OEM fuel pump off eBay (used) and it also has bubbles, so...... See what I mean about a dark cloud!! I hope I’m not running the bike too lean with all the bubbles in the fuel. I look forward to getting the spark plug wire rpm gauge as I feel I’m over revving it on the highway. I wanted to go down to a 13t for trail riding as with the 14t I can still do 16 miles/hr in first which is pretty fast for the technical stuff. Any suggestions are appreciated as I’ve got too much $$ and life sunk into this bike I need to figure it out and get some joy from it!! Thanks in advance....
something not right to state the obvious do you run the bike with the ecu for the engine you bought ? do you have the throttle body fitted ? is the air filter clean when changing the throttle body did you change the hose fitting to the 250l one as the 300 one has a bad feed angle could cause kinking problems have you installed the 02 sensor back in the system did you reset the tps after instalation the bike should easy be in the 60 /65 us mpg range 15/40 is a much more practical gearset for travel ..... id start by putting everything back to the original honda set up ..the symptoms you describe suggest too much fuel and n not enough air ..so id start by doing that everything as honda intended see how the mop flops from there its 286 cc engine and it should get up to the low 80s on the level but from 70mph on its pushing a lot of air so dont expect too much id say it would probably be 7/8mp better off than stock but should be able to go along all day in the low 70s as a guide this is mine 30.000 miles up now full luggage knobbly tyres and barn door screen and is happy in the low 70s all day long ..tbo you cant really expect much more from a 30hp engine so in that context i think it does pretty well ..as long as you motor is healthy there will be a cure im sure
Thanks so much for the helpful advice, I knew something was amiss but I'm a complete mechanical newb so I'll forward your comments onto my buddy who did the swap. He was following the guidance on here from others that had done the work before. Basically he changed the two fittings and installed the O2 sensor in the header. I'll answer what I can and I've forwarded your comments to him as well. Yes he used the 300 Ecu. Yes he installed the throttle biddies. He did not reset the TPS. The air cleaner is good. It has the 250l hose fitting. So looking at your list of possible issues the only thing that appears to be amiss is not resetting the TPS. Could that be the magic bullet to my power and poor fuel economy issues (seems too good to be true!!)? I have the shop manual with the instructions but it would be helpful if there was a video given my lack of mechanical ability. I googled it but only the Honda Monkey and Grom came up, are they the same? If not can someone send a vid link..? Thanks so much folks!!!
Update.... Today I checked the codes and I got 1 long flash and 2 quick ones for a reading of 12. That suggests a MAP high voltage or circuit malfunction. I reset the TPS and did a Hwy test ride for 40 miles round trip. On the way out I got up to 75 mph top speed (GPS corrected) which was 4.5 mph faster than the last time (-5% for the speedo reading too high). But on the way back I could not get over 71 mph, so not sure if that means I had a tail wind on the way out and a head wind on the way back. I can live with that for a top speed, but what I'm not happy with is the crappy fuel mileage. This time I got 41 mpg (minus 5% for speedo error), where as last time I got 42.5 mpg..... Mind you I was doing a number of WOT tests..... The last road test I did 22 miles around town aa a comparison and only got 36.5 miles/gallon!!! So the TPS reset did not seem to do much :0( I'm thinking of taking it to a Honda shop and getting them to check out my fuel pump flow rate, bubbles issue, the MAP sensor and anything else they can think of.... Suggestions/thoughts....?
If your MAP is bad, then you will get bad fuel mileage. Just a side note, for Miller is best tested over a whole tank. Testing at 20-40 miles could skew the numbers artificially high or low especially when you have a small tank.
Is the MAP the same part in both the 250 and 300..? I can find the 300 MAP part number 136200-2660, but I can’t find it for the 250. I’m assuming they are the same because there was no instruction to install the 300 MAP when doing the transplant. Thanks!
having gone so far i guess getting it plugged in to a dianostic to see if the values are good on all the gubbins seems a good idea reading it back you have a 14/42 on ?? the cbr300 engine has slightly shorter 6th gear so according to gear commader your south of 8000 revs at 70 ...peak touque on them engines is nearer 6600 so it could be your running past peak power with the revs and of course 8000 plus revs wont help consumption ... but 36 us mpg is pretty bad ...10mpl .. where it should be 17 mpl on average hard to say is the bike ticking over well pulling cleanly ..does it cough or stall as you set off or stop ..in other words does it feel like its in good health when you open the throttle ? with that gearing id say it should pull quite spightly up to 60mph with reasoble close shifting points ... and then tail off as the revs run past peak power.,.similer tyhing happens when you put a 13 on a 250 it pulls cleaner aright but throws in the towel a bit earlier higher up im only guessing but if you look at the touque curve your running at 8050 revs at 70 and guess where the peak power curve falls away ?? yup 8050 revs maby its as simple as that ..try and gear it better see how that works ??.15/40 is more practical around 7k revs at 70 and near on top of the touque curve there with a1000 or so revs left to peak power in effect 14/42 is like running five less on your rear sprocket than i am ..id wager you will get a better top speed with less revs on longer gearing ..all this asumes there nowt wrong with the engine or fueling
Hi Minkyhead, thanks again for all your advice, as you can tell I’m dangerous anywhere near a tool. I goofed and I have the stock 40T on the rear, not sure if that affects your comment/suggestions much. Do you know if the 250+300 have the same MAP? It pulls well off the line well, no hesitation or coughing/sputtering through the gears. With this gearing it goes up to about 17 mph before needing to shift into 2nd ( for fast acceleration). I went with this gearing for better slow speed control on dirt trails. I find this is still too fast for steeper uphill rocky climbs. I was not able to try the 250cc as the motor was pooched so I don’t have anything to compare it to. But I would have thought it would have been “snappier” especially with the 300f motor. I wish the non Rally model would have come with the built in tach like the Grom/CB! Front tire pressure was 24 and rear was 27 on the stock tires at about 40% tread left. On a Govt commercial Hwy scale (accuracy on lighter loads?), the bike is 415lbs with 12 litres of fuel ( I pack some tools and have a rest top box with some supplies, racks, skid plate, tank bag and I’m running one of those universal wind screens with an adjustable wing on top). I’m okay with 72 mph top speed, but I need to figure out the crappy fuel mileage given I want to do some light touring off pavement on it so I need the range. I’m wondering if having the fuel pump flow rate checked to see if the bubbles coming from the bottom of the fuel pump in the tank are affecting anything...? I’m thinking that air is getting into the system somehow? given both fuel pumps (stock one I dropped on the cement floor and the used one from eBay) have bubbles...? Thanks again for the help!
Hi folks. Well I went to the local Honda shop this morning (next one is 200 miles away) for help diagnosing the low top speed, poor fuel economy and bubbles in the gas tank from the fuel pump issues and below is my experience. I worked on my CRF issues as far as I could so I decided to have Cycle North Honda help with further diagnosis given their trained/experience technicians. I'm trying to address: lower than expected top speed (113km/hr versus ~125km/hr GPS corrected) lower than expected fuel mileage (50 HWY and 46 City, should be ~70 HWY) there are bubbles coming out from the bottom of the fuel pump in the tank, the same thing was happening with the stock pump so I ordered a used one off Ebay and it did the same thing I checked for error codes and its pointing to a bad MAP sensor (code 12) and I wanted them to check my 2 fuel pump flow rates (stock and used Ebay one) to make sure it was in spec given the bubbles. After I explained the problems I'd like diagnosed (ie: I was thinking spend 1-2 hours checking things out) the front counter person was setting up an appointment date and asked me if I had a Yamaha.....? Then he asked the Service Manager how best to help me and he told him I had a CRF450 with a 300L motor.....????? After the Manager listened to my request he said he would not have his technicians work on the bike because 'it was a box job' as the motor was not stock. I explained its just a plug n play transplant and folks have done many of them, but he repeated he would not take the job as it was a mix of parts. I re-iterated all I wanted them to do was to test the function of the MAP, look for what was causing the tank bubbles (he said it might be because of how the pump was returning fuel to the tank (the return line? but he did not know how that looked on a CRF250 fuel pump). He said as long as the bike is running okay it might not be a problem, or there might be a pin hole leak. He asked what type of aftermarket tank did I have, Acerbis I said. He asked if there were bubbles when the tank was low versus full, so he did try a bit to diagnosis remotely. And I wanted them to check fuel flow rates on both my fuel pumps. He suggested I get a service manual, I said I have one but I'm mechanically inept so I took the bike as far as I could and now I need help. He said he did not want his technicians chasing down a problem for 1-2 days and giving me a $2300 bill. I said I did not ask them to do that, I re-iterated I wanted them to take 1-2 hours to plug it in and check things out and let me know what they find (do a test ride...?). He said no. I said "even though I'm willing to pay you by the hour to do a diagnosis", he said no. So I asked him where else I could take it and he said Yamaha should have technicians that can do a voltage test on the MAP, so I said 'but don't you"....? He also suggested Excalibur. He said he was sorry and he did not want to upset me....... So my challenges with dealerships continue and why I'm so thankful for these forums! Should I just order a new Manifold Absolute Pressure sensor (MAP) and try that? I can't find the part number for the 250, it is the same as the CB300F (ie: 136200-2660) as nothing is coming up via my Google searches?
The part number quoted is the Denso part number, not the Honda part number. eBay shows Honda CBR250 R Air Valve Switch Solenoid DENSO 136200-2660 Honda part number - 2016 CB300F AC - AIR INJECTION SOLENOID VALVE 36450-KVK-902 That's not a MAP. The corresponding CRF250L part could be the AIR INJECTION SOLENOID VALVE assembly (several parts). VALVE ASSY., AIR INJECTION SOLENOID 36450-KVZ-631 The CRF250L MAP is in a Sensor Unit, with 2 other sensors. The Sensor Unit is attached to the throttle body. SENSOR SET 16060-KYJ-901, $48 It appears the 2 systems you are dealing with have some significant differences.
Thanks ramz for catching that, I'm such a newb. So is this the ‘box’ where the MAP sensor is in? I wonder if a bad injector could be the problem...?
Here's the parts fiche shown by patsfish.com: Assembly #1 - SENSOR SET 16060-KYJ-901 Retail $64.89 Your price $48.67 partsfish.com Nothing IN the box is shown as available for purchase from Honda, but there may be vendor part numbers on individual sensors. I would suspect a dirty injector first... #13 INJECTOR ASSY., FUEL 16450-MFE-641 Retail $150.15 Your price $112.61 partsfish.com Injectors can be cleaned and reused.
Thanks ramz, we'll try the 'box' and injector from the CB engine to see if that makes a difference. The price on this injector seems too good to be true..... Interesting how one injector can work for so many bike models. https://www.amazon.com/Unlimited-In...ds=cb300f+fuel+injector&qid=1594793490&sr=8-3
Update..... Met my buddy who did the transplant and we swapped out the MAP box from my old 250 motor. On the way to meet him was a 65 Mile Hwy ride and I got 44 mpg. After the swap I went for a 25 Mile Hwy test and the mileage was 48 mpg. I also did a WOT speed test and got up to 73 mph which was not much of an improvement. Then I rode back home the 65 Hwy miles and got 52 mpg corrected. So I went from 44 before the swap to 52 after, so I’m cautiously optimistic. Btw, I’ve got the bike set up for touring so it weighs in at 395 pounds with a full 3 gallon Acerbis tank, my top box, tools, tank bag, wind screen. Add to that the 200lbs of my wieght and the 14/40 sprocket set up. I’ll do some more testing as is and see how it goes.....
Mate -check that hose isn’t crimped or twisted - from tank to injector - easy as - get your mechanical buddy to lift the tank !! When swapping the T/B hose has different routing for CBR300R tank .. I used the CRF hose.. The injector from the CRF T/B will work just fine in this if you want to eliminate that too... (I am not saying its the same injector - I think (maybe) Shortman said it’s not? - I am just saying it will work fine for the purposes of fault elimination. Been running my 38mm T/B like that for a while (with CRF injector)
Omfg - how do you release the ecu pin 23 ?!!!? I have everything else done but can't get that frickin' pin out!!! AAAARRGGGGGHHH The rest of the engine swap has been a walk in the park.