2010 CRF250R Crank
Posted 04 December 2011 - 06:35 AM
I over maintain this bike. I use synthetic oil in the crankcase. There is no reason for lubrication failure on my part.
The bike has 80 hours on it. The rod bearing went out. The rider is an Intermediate rider. I have seen many bikes ridden harder than this one.
I understand that there are aftermarket cranks that have addressed lubrication issues that the OEM cranks are deficient in.
Has anyone addressed this with Honda?
Posted 04 December 2011 - 06:44 AM
We allways use oem cranks, never hot rods etc. We do have them balanced, trued and welded.
Posted 04 December 2011 - 06:46 AM
Posted 04 December 2011 - 07:12 AM
WHAT? 80 hours and you swap the cranks, are you racing?
Posted 04 December 2011 - 07:12 AM
Wow, I cant believe changing a crank every 50 hours. That would 2 crankshafts a year or more for me. How can you afford that? It's a shame that modern production bikes are that high strung. It prices the regular guys out of the game and isnt good for the sport. Who wants a dirt bike you have to replace a crankshaft, top end, etc. multiple times a year?
Posted 06 December 2011 - 06:36 AM
Posted 06 December 2011 - 07:53 AM
Posted 06 December 2011 - 08:28 AM
Power comes with a price - and the modern four stroke you purchase puts out a lot of power for a 250cc machine!
To top that off, honda has both the shortest stroke AND rod of the bunch - making the inertia loads even worse...
Posted 06 December 2011 - 11:38 AM
Posted 06 December 2011 - 12:04 PM
the most recent was replaced at 20 and the cage was showing wear at the point where the roller ends come in contact. We change oil after every race weekend.
Posted 11 December 2011 - 03:27 AM
Posted 11 December 2011 - 05:52 AM
I change my crankshaft this year because rust on the transmission side bearing wear the crank a little. But I don't plan to change it before december 2013. I know a lot of racer with the same bike never change the crankshaft after 3 hard racing season.
Posted 12 December 2011 - 03:07 AM
This one used to be owned by a top ranked queensland based Junior racer raced at coolum sands Running the big no no oil ( Will post Pro X data release) on how all CRF250R must not run certain motul oils specifics are 7100V interesting as this is from the Netherlands head office I have requested this today so i can post it on my counters as Owners love motul but the 7100 v is major contributing factor when valves are not involved. I see both sides I love major rebuilds got to the bike after a 2 hour drive and cases were not usable so going to be an easy one cylinder is baked so May go BIG BORE Yummy order dyno results and stick a new hour meter and lets see how long this engine can run as These racers i got this bike from are blowing all types of bikes up. Running in a sand track and perhaps one would be happy at 60 hours on this engine. But I truely expect more reliability from my race engines. Pure HP vs reliability will put the neck out. Will confirm you are right my Honda Tech says the bike is lean also so bolting on PC V will give us some tunability. EFI tech bulletin Yamaha Engineers note yamaha still refuse to use efi on the 2012 YZ250f and i can see why its just sacfricing reliability these EFI models are requiring good mechanics to get real involved and update them Hopefully they catch this and STOP the 7100v use.
You may be interested to know the following
The Head dropped a valve on exhaust side ( What I refer to as a reverse slam which goes and feeds the big end a good amount of force this one smashed the crank to lower part of crankcases shaving the crank and smashing the casting between gearbox area and engine area i will post pics as they spell it right out buts still a bargain i am happy to say cylinder and cam are ok will check the laps tonight takes some pics as it was and this spec i provide will be of interest and is easy and readily available through parts unlimited dealers and or good dealership. Delwest is a new item for me but noting they have a long relationship with pro circuit and thats good enough for me. Cylinder options are open as my normal supplier has no stock except an athena stock cylinder kit and at the price we can put a new crank in it and Bigbore as the local distributor wants a fair bit for it. Full Crank case rebuild both sides coming in way under budget so Hi Comp on stock cam or stage 1 hotcam .............Hmmmm note all other stages of the hotcams for people that may be running builders series please let us know your thoughts if running a setup close to and what hours are running on hour meters.
I have changed my workshop out to use castrol oils and getting 12 month test data in on some of my test bikes and all above expectations
KX250f 2010 Model 80.3 hours and first valve shim adjustment was required one one inlet valve only. Castrol Racing oil the whole time at 5 hour intervals this is a great result and this bike is flogged hard.
Look forward to responses and appreciate everyone input I am into reliability as i want my kids to race but i am not throwing cranks in bikes like this everyday of the week. There is a cause and effect rule as Honda engineers would not of planned for us customers to be rebuilding cranks and rods at these intervals and we know it happens but i have had many different hondas and thats why we like the hondas they are well engineered swap the oil if this is happening to you change the air filter and watch this space as these will start to go bang if they haven't already.
I will be looking for stem to guide clearance movement and i have seen under the valve yet but my guess there is going to be movement there also . Stop just shimming all the time as a tip do three shim adjustments then full tear down for the rods sake..
Posted 12 December 2011 - 04:22 AM
Edited by speedboot, 12 December 2011 - 04:43 AM.
Posted 13 December 2011 - 01:15 AM