Alex687 Posted September 4, 2016 Share Posted September 4, 2016 Hi, I'm a new rider having just passed my CBT and purchased a 2005 XT125R in the last fortnight. I rode up to visit a friend this weekend. I'll talk about all aspects of the trip that i think could possibly be contributing to what happened. The trip involved a 1.5mile off road climb and there was no running problems on the way up. Although the idle was so low that it actually struggled to keep going when left to idle. The bike then sat outside uncovered for 48 hours and got a thorough soaking due to the typically terrible UK weather. The bike also has a fuel cut off tap that I usually close but I actually forgot this time so it was open the whole time. When I came to start it on Sunday I couldn't kick it into life (previously it always started 1st or 2nd kick) so my mate helped me bump it and we got it going but it didn't sound very well, and was still struggling to idle. I set off back down the off road decent, obviously never really loading the engine during this decent. In fact for parts of it i didn't even have the engine running. So I got to the bottom and onto the road, where I could start loading the engine a bit and immediately noticed it hesitating when I gave it throttle at low revs. This gradually got worse and worse and after half a mile I started to climb again and it became incredibly bad, hesitating, sputtering, occasionally kicking in with a bit of power, before bogging down again. It wasn't long before I came to a halt because it simply wouldn't produce enough power. I looked round and there was a big cloud of whitey blue smoke. Luckily there was a garage nearby and even more lucky it was open on a Sunday! So I wheeled it there and we had a little look. The spark plug was very sooty, there was still compression, and a spark, and plenty of fuel in the tank but it wouldn't fire up. After it sat for a while we noticed the sump had filled up with petrol. I'm no expert but if I had to guess I would say there is an issue with a stuck float (this could also be causing the struggling idle). In the two days the bike was sat with the fuel line open, fuel has slowly seeped through the carb and into the engine, found its way around the rings and mixed with the oil. This was maybe leading to the bike not starting and sounding rough when it bump started. As I descended, because I wasn't loading the engine i didn't notice the problem. The next part I don't know - why did it get worse and worse and then why was there a big cloud of smoke before it died. I'm hoping I haven't damaged any internals and I can get away with new oil, filters, carb clean, etc. So what do people think? any help/advice much appreciated Link to comment Share on other sites More sharing options...
Moderator Cynic Posted September 4, 2016 Moderator Share Posted September 4, 2016 Fuel in the oil will dilute the oil. It can then get past rings and valve seals. Link to comment Share on other sites More sharing options...
KevtheRev Posted September 5, 2016 Share Posted September 5, 2016 I think you're correct Alex . Check your fuel petcock is sealing properly , then float height and the condition of the float needle and seat . Best of luck ! Link to comment Share on other sites More sharing options...
Alex687 Posted September 6, 2016 Author Share Posted September 6, 2016 So I drained my engine of oil and took the casing off each side. I discovered a spring beneath the oil "filter" that looks like its come from an oil seal. http://s1300.photobucket.com/user/alexofsmeg/media/1815CFC0-F47D-4D57-BA00-F216B6F70745_zpsuwvi4zgc.jpg.html?o=1 It looked like it must have been 50-60mm diameter if it was from an oil seal. I looked at lots of parts diagrams and couldn't figure out what it was from. Then I found a video on youtube and saw this: http://s1300.photobucket.com/user/alexofsmeg/media/01005F40-9C73-4898-8A90-27220B8DF547_zpsdgnmvy60.jpg.html?o=0 Some sort of crank shaft seal on the inside of the flywheel side of the crank casing I think. Is this an oil seal and do people think that spring came from here? I hope I don't have to dismantle the whole engine!!! Link to comment Share on other sites More sharing options...
slice Posted September 7, 2016 Share Posted September 7, 2016 Not sure about the size of this spring (I'm used to imperial numbers!) but if it's what I think it is then yes your going to have to replace the seal, most seals have an internal spring that helps them keep their shape and strengthen the seal they make, so it looks like your seal has shed it's spring retainer and dumped it into the oil at the bottom of the engine, you have no choice other than to replace it I'm afraid and if that means a strip down then your going to have to do it. This is what I'm talking about or this Link to comment Share on other sites More sharing options...
Alex687 Posted September 7, 2016 Author Share Posted September 7, 2016 Yea. That's what I thought it was from. But which oil seal...? Link to comment Share on other sites More sharing options...
slice Posted September 7, 2016 Share Posted September 7, 2016 Well your going to have to look at your Haynes to get that answer but if one has blown then it's a fair bet the others will need looking at as well, your best bet, buy a shit load and fit them all new. They should only cost about £4 each I would think. Link to comment Share on other sites More sharing options...
Alex687 Posted September 8, 2016 Author Share Posted September 8, 2016 I got the engine off last night. Will strip it down over the next few days and hopefully figure out where it came from and what needs replacing Link to comment Share on other sites More sharing options...
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