nico Posted August 22, 2019 Share Posted August 22, 2019 (edited) I was riding in one of the country roads back home instead of taking the freeway and had a friendly duel with a guy in an Audi S5 and was within his sight but at a safe distance. The bike was exceptional with the torque kicking in like the ip-man punch mid battle and with the suspension under load the maneuverability was like a wraith chasing it's target. Unfortunately the guy decided to give in during the battle and took a turn and I was carrying a bit of speed around the corner but the bike wasn't under the same load as before and so it decided to go off the road on a tangent. I let go of the throttle and tried to brake, but I saw the grass on the side of the road and in the blink of an eye was in it. I though okay, at least I didn't fall and just thought I could ride it off and get back on the road, but then I hit a ditch and that lifted the bike's rear wheel off the ground a good two feet or more, incredibly I didn't fly off over the handle bar. Luckily I was able to hold on to the bike and recover to get back on the road and I need to thank my guardian angels for that, but the bike wasn't the same after that. I parked it to the side of the road thinking the exhaust or worse the engine cover was damaged, but the grass and mud combo had cushioned the blow. Had some mud around the oxygen sensor and main stand but nothing else. The rear wheel and the swing are fine. Coasted on neutral and it was riding freely. But when I gave it gas, at around 4,000-5,000 rpm the power seems to dip and the torque in the power band is low, it also feels like there's some starvation. I came back home and gave it a good power-wash and looked for signs of damage and couldn't see anything. No leaks of any fluids or things bent out of shape either. Tried to tug the exhaust to see if it was lose or damaged and no sign of that either. So this morning decided to take it out again and I'm definitely noticing the loss of power, so I suspect the throttle body is out of sync or the cam chain timing is off or the exhaust is blocked and the back pressure is the cause for this loss, it could also be the oxygen sensor is damaged. If anyone has experienced this type of a loss in torque and power, please let me know what's the culprit. I'll post pics tomorrow if needed. Thanks for sticking around to read this long message. Edited August 22, 2019 by nico 1 Link to comment Share on other sites More sharing options...
angrygirafe Posted August 22, 2019 Share Posted August 22, 2019 I got nothing for advice, but wow, glad to hear you’re okay! 1 Link to comment Share on other sites More sharing options...
Supporting Member roadrash83 Posted August 22, 2019 Supporting Member Share Posted August 22, 2019 Check to see if the bike is showing any codes. 2 He who dies with the most toys wins. Link to comment Share on other sites More sharing options...
nico Posted August 22, 2019 Author Share Posted August 22, 2019 7 minutes ago, roadrash83 said: Check to see if the bike is showing any codes. Does it matter that the check engine light isn't illuminated? Just pulled out the O2 sensor. Looks beaten up, but nothing extraordinary. Link to comment Share on other sites More sharing options...
koth442 Posted August 22, 2019 Share Posted August 22, 2019 Sorry, no troubleshooting advise, but holy cow what a story! 1 '15 FJ09 Link to comment Share on other sites More sharing options...
Supporting Member roadrash83 Posted August 22, 2019 Supporting Member Share Posted August 22, 2019 That O2 senser looks like it took a good hit if you didn't do that damage taking it off. I would replace it, you have the Denso part number you might be able to buy it at an auto part store cheaper than the Yamaha dealership 2 He who dies with the most toys wins. Link to comment Share on other sites More sharing options...
Supporting Member betoney Posted August 22, 2019 Supporting Member Share Posted August 22, 2019 19 hours ago, nico said: I was riding in one of the country roads back home instead of taking the freeway and had a friendly duel with a guy in an Audi S5 and was within his sight but at a safe distance. The bike was exceptional with the torque kicking in like the ip-man punch mid battle and with the suspension under load the maneuverability was like a wraith chasing it's target. Unfortunately the guy decided to give in during the battle and took a turn and I was carrying a bit of speed around the corner but the bike wasn't under the same load as before and so it decided to go off the road on a tangent. Glad to hear you are OK but I couldn't exactly tell what happened from your description. You were racing an Audi and overshot a corner? ***2015 Candy Red FJ-09*** Link to comment Share on other sites More sharing options...
nico Posted August 22, 2019 Author Share Posted August 22, 2019 2 minutes ago, roadrash83 said: That O2 senser looks like it took a good hit if you didn't do that damage taking it off. I would replace it, you have the Denso part number you might be able to buy it at an auto part store cheaper than the Yamaha dealership Yea, thought of replacing it. Couldn't find it on any of the autoparts store online. I'll probably drop by with and check with them in person, thanks for the advice. Link to comment Share on other sites More sharing options...
nico Posted August 22, 2019 Author Share Posted August 22, 2019 (edited) 3 minutes ago, betoney said: Glad to hear you are OK but I couldn't exactly tell what happened from your description. You were racing an Audi and overshot a corner? Thanks, racing and he threw his hat in, took a turn and I continued onwards, I was off the throttle by then and so the bike was lower in RPM than some moments ago, it kinda unloaded the suspension, 1 corner later I was off the road. Edited August 22, 2019 by nico Link to comment Share on other sites More sharing options...
tktplz Posted August 24, 2019 Share Posted August 24, 2019 So have you tried another O2 sensor? Did you take it to the dealer or are you profecent in using tools? Enquiring minds have to know....... Ain't no fun when the rabbit gets the gun! Link to comment Share on other sites More sharing options...
nico Posted August 26, 2019 Author Share Posted August 26, 2019 On 8/24/2019 at 2:03 PM, tktplz said: So have you tried another O2 sensor? Did you take it to the dealer or are you profecent in using tools? Enquiring minds have to know....... I couldn't find the denso sensor in any of the auto parts store, so I'll have to go to my bike's showroom that's at the other end of the map to get one. In the meantime, I just cleaned this one up and it works fine (for now). After spending a lot of time looking at the engine it dawned on me to check the front wheels. I tried the hand rotation tests and I'm definitely getting some friction. I'll try to post a video of it sometime later today, but looks like a bent wheel axel or the bearings are worn out. Link to comment Share on other sites More sharing options...
tktplz Posted August 26, 2019 Share Posted August 26, 2019 3 hours ago, nico said: After spending a lot of time looking at the engine it dawned on me to check the front wheels. I tried the hand rotation tests and I'm definitely getting some friction. I'll try to post a video of it sometime later today, but looks like a bent wheel axel or the bearings are worn out. Well that sux. Sorry to hear that but going through a ditch might have bent something. Do stuff like take the calipers off let them hang and spin the front tire. Loosen the axle and see how it does. then on to checking the axle, then the rim. Not sure how you check forks. I'm sure someone will chime in. Good luck, I know it would be driving me crazy. It's my bike man, an extension of me......and it's hurting. 1 Ain't no fun when the rabbit gets the gun! Link to comment Share on other sites More sharing options...
nico Posted August 27, 2019 Author Share Posted August 27, 2019 On 8/26/2019 at 6:44 PM, tktplz said: Well that sux. Sorry to hear that but going through a ditch might have bent something. Do stuff like take the calipers off let them hang and spin the front tire. Loosen the axle and see how it does. then on to checking the axle, then the rim. Not sure how you check forks. I'm sure someone will chime in. Good luck, I know it would be driving me crazy. It's my bike man, an extension of me......and it's hurting. Thank you so much for your empathy. Yes, it feels terrible trying to figure out what's gone wrong. I'll get to working on the bike this weekend again and keep this thread posted on what I discover. Hope you all ride safe and enjoy your rides, cheers! Link to comment Share on other sites More sharing options...
nico Posted September 1, 2019 Author Share Posted September 1, 2019 Got the brake calipers off the front wheel and checked for sway (lateral and front/back) also checked for friction and axel or wheel bend. All went fine until checking the rims and brake rotors for unevenness. So is it possible for such little variation to be noticeable while riding?? Link to comment Share on other sites More sharing options...
vincep Posted September 2, 2019 Share Posted September 2, 2019 I would say no. I have more run out than that on one of my older bikes (1985) and it is per spec. The video showing the left disk to fork gap looks pretty good. The video screw driver to rim - just because there is a high spot of the wheel casting does not mean it is out of true. Hopefully someone on here who is actually qualified to comment will give better advice - not some shade tree wannabe like me 1 Link to comment Share on other sites More sharing options...
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