MrMetthew Posted August 17, 2016 Share Posted August 17, 2016 Hey everyone, My mate has a wr250f, I thinks it's a 2008 model (with the al frame). Yesterday we were riding, and at approx 50mp/h his rear wheel just blocked up! Fortunately he was able to hold the bike under control to a stop. Anyway, after that engine was stuck, kickstart kan be kicked sometimes with some effort, but we quickly stopped messing with it. He bought the bike just weeks ago second hand, so we don't have a real history on the bike. But it looks really well looked after, really mint. But also all the electronics (starter, speedo, battery,..) are removed so it also looks like somebody in the past converted it for pure offroad/racing so it may have been ridden hard in the past, who knows. The engine is still stuck when in neutral, so I expect something in the top end, maybe crank bearing went or valves, no idea. The bike was running mint before this, and was not overheating when this happened. Anyone seen these wr250 block seize up? Some insight into what it might be? The only thing I can think of now, is to open it up and see. I convinced my friend not to take it to a garage or to the "stealership" and that I would rebuild the engine together with him. I have rebuild three dt125 two stroke blocks, top ends and bottem ends. But I know nothing about four strokes, will this be a doable project? Are these wr250 four stroke blocks really that much harder to work on than say a dt125 two-stroke block? Also due to circumstances we will not be able to start on her before the end of the month. I'd better be prepared I'd figure? Do anyone knows which custom tools we need to extract the wr250 engine from the frame and to open it up? I have all the normal tools, also flywheel extracter and case splitter tool for dt125, will these fit on the wr250? I ask so we can order them in advance, before we start on the engine. So far the only thing on my to-order-list is a wr250 workshop manual. Thanks guys! Link to comment Share on other sites More sharing options...
KevtheRev Posted August 21, 2016 Share Posted August 21, 2016 Did you check it for oil ?? 1 Link to comment Share on other sites More sharing options...
MrMetthew Posted August 24, 2016 Author Share Posted August 24, 2016 I only had time to take a quick look at it. The glass window was very hard to look through, but I was pretty sure there was oil yes. The bike was just maintenanced by a dealership, so boy that would be something if that turned out to be the problem! Anyway, this sunday or after the weekend we'll probably start opening her up. First thing I am going to do is check the amount of drained oil. Link to comment Share on other sites More sharing options...
KevtheRev Posted August 24, 2016 Share Posted August 24, 2016 Rule out the simple things first eh' ? If she's low on oil check the camshafts for blueing . Hopefully It will be something small though . Good luck . Btw , 4 strokes can be more complicated and expensive to rebuild , unfortunately . Link to comment Share on other sites More sharing options...
Moderator Cynic Posted August 25, 2016 Moderator Share Posted August 25, 2016 13 hours ago, MrMetthew said: I only had time to take a quick look at it. The glass window was very hard to look through, but I was pretty sure there was oil yes. The bike was just maintenanced by a dealership, so boy that would be something if that turned out to be the problem! Anyway, this sunday or after the weekend we'll probably start opening her up. First thing I am going to do is check the amount of drained oil. The first words out of the mouths of the dealership would be 'prove it'. You said yourself its all but a race bike and you pay for the performance by accepting an amount of reliability risk. Unless you find a fingerprinted smoking gun you will get squat from the stea...dealer. 1 Link to comment Share on other sites More sharing options...
MrMetthew Posted August 25, 2016 Author Share Posted August 25, 2016 Yeah, I know, we would have no goddamn leg to stand on. Luckily that dealerschip is run by a mate of ours, then again that could just make it more ugly :s. But I wouldn't dare to throw any accusations around without even fully checking the bike first. Verstuurd vanaf mijn SM-A510F met Tapatalk 1 Link to comment Share on other sites More sharing options...
MrMetthew Posted August 30, 2016 Author Share Posted August 30, 2016 Update: Okay, so we started on the wr250. Got the engine out this evening. Not too bad, struggled a bit with a seized up pivot axle, but all in all got the engine out alright. Unfortunately we had to stop for the evening, not enough hours in a day. Tomorrow we'll open the engine probably, very curieus to see what we'll find in there! Link to comment Share on other sites More sharing options...
MrMetthew Posted September 2, 2016 Author Share Posted September 2, 2016 UPDATE: Okay, we removed the head. Valves, cylinder, piston all looked mint! BUT the crank is seized! It kinda turns partially sometimes but than seizes up when you turn a bit further. Also is blue around the part where its stuck. Big end bearings seem ok but have to split the case to check. Waiting for correct flywheel puller to do that. Do cranks just seize up on their own? Can we just replace it? Or do we need to find the reason for the crank seizing? https://s14.postimg.io/4aast20ov/20160830_213828.jpg[\IMG] Verstuurd vanaf mijn SM-A510F met Tapatalk Link to comment Share on other sites More sharing options...
Moderator Cynic Posted September 2, 2016 Moderator Share Posted September 2, 2016 Not sure as to why but had the same thing happen to a v8 landrover engine. It was only tight at one point. I just put it down to abuse maybe some oil starvation as it was a trials ( they get to some interesting angles) engine and the last thing they get is mechanical sympathy. 1 Link to comment Share on other sites More sharing options...
KevtheRev Posted September 2, 2016 Share Posted September 2, 2016 The blueing is a sign that the bearing has overheated . Maybe due to a low oil level/starvation or wear and tear . Link to comment Share on other sites More sharing options...
slice Posted September 2, 2016 Share Posted September 2, 2016 High revs low gears and going up hill, as Kev say's oil starvation and as Cynic said Abuse. Link to comment Share on other sites More sharing options...
anyoldiron Posted September 7, 2016 Share Posted September 7, 2016 Unfortunately 4 stroke dirt bikes are trouble waiting to happen.......................as a 2 stroke ones, the latter just dont cost the earth to fix. The bearing is probably ''welded;' to that crank end, as it got hot enough to blue it its strength will be compromised ,so i would replace that crank end. Post some pictures of the inside of the engine when you open it up, especially the bottom off the inside , then we can see if there is a lot of crud built up which may mean you have a oil way blocked/partially blocked. lts hard to say from a distance, but im leaning towards what Cynic said, odd angles, revving the bollocks out of it in low gear, that combined with crap oil, low oil, contaminated oil, slightly worn bearings can all make it go boom. Link to comment Share on other sites More sharing options...
MrMetthew Posted September 7, 2016 Author Share Posted September 7, 2016 Thanks for the feedback, will certainly post pics when we open the case. That wil probably be tomorrow if the flywheel puller arrived. We were thinking to Just order a whole new crank assembly, with the blueing and all. Or do you guys think this one would be a cannidate for rebuilding? Verstuurd vanaf mijn SM-A510F met Tapatalk Link to comment Share on other sites More sharing options...
blackhat250 Posted September 7, 2016 Share Posted September 7, 2016 Mind check the oil pump before rebuild, . , there has to be a reason , it seized , 1 Link to comment Share on other sites More sharing options...
MrMetthew Posted September 19, 2016 Author Share Posted September 19, 2016 UPDATE: Ok, so we ordered parts, all included we paid a little over 600euro. That's even a bit more in "island money", for all you British folks . I don't rebuild engines without changing the main bearings so that added a little bit to the costs. Anyway the oil pump looked mint, so we're still contemplating how the crank seized. If anyone has some more input on that, that would be greatly appreciated. Honestly were thinking selling her when she's up and running again as we don't want to be bothered with another seized crank. If we can figure out why the crank seized we keep her for sure. Don't be afraid we will mention the replaced seized crank to the buyer, I don't do slimy rippoff sells, not my style. Verstuurd vanaf mijn SM-A510F met Tapatalk 1 Link to comment Share on other sites More sharing options...
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