archiel Posted March 4, 2019 Report Share Posted March 4, 2019 (edited) Hi, I sadly seized my 2010 290 Evo (only 72hrs). I fell off and the throttle cable came out of the handlebar housing so the bike hit full revs on its side. the engine wouldn't cut, and it wasn't till the carb drained that it turned off. Not realising that the throttle cable was stuck i started it again and the same thing happened and this time it seized. So got the barrel Nikasiled and fitted a new piston and rings. The bike now runs but with very little grunt to it. It revs and starts fine, but soon as you try and move there is no power at all. If you cruise around in first and give it a blip of the throttle there is no power to lift the front up. I would love some help on understanding what i may have done wrong to cause this lack of power! A couple of things to note during the new top end: 1. When i first started the bike after the new piston, the slide in the carb was stuck open (no idea how as i rebuilt the carb and would have checked the throttle) so the bike hit full revs for about 5 secs before i could turn the bike off. I imagine this was not great for the new rings so could this be the issue? (I had lubed the rings and piston with 2 stroke oil when putting back together). The bike started fine the second time after i checked the slide. 2. When i took the bike apart it was running 1.3mm base gasket (1mm + 3mm) . I only had access to a .6mm new one, so decided use the old 1mm + .6mm base gasket. This meant the squish was way of spec so i thought this was the cause the of the lack of power. However last night I took it apart and only put the .6mm gasket which made the squish in spec. This had no effect to the power. Would be great if anyone had any thoughts on this? I am bit out of my depth now! Let me know if anymore information is needed to understand the issue. Thanks! Archie Edited March 4, 2019 by archiel Quote Link to comment Share on other sites More sharing options...
lineaway Posted March 4, 2019 Report Share Posted March 4, 2019 Did you put the piston in backwards? Quote Link to comment Share on other sites More sharing options...
archiel Posted March 4, 2019 Author Report Share Posted March 4, 2019 (edited) Hi lineway, yeah put that in correctly, with arrow pointing towards exhaust port (even took a photo of it incase i doubted myself!) Edited March 4, 2019 by archiel 1 Quote Link to comment Share on other sites More sharing options...
b40rt Posted March 4, 2019 Report Share Posted March 4, 2019 Have you checked timing, not unknown for woodrough key to sheer allowing flywheel to spin on shaft, altering timing. Quote Link to comment Share on other sites More sharing options...
archiel Posted March 4, 2019 Author Report Share Posted March 4, 2019 13 minutes ago, b40rt said: Have you checked timing, not unknown for woodrough key to sheer allowing flywheel to spin on shaft, altering timing. Hi b40rt, Cool will look into this and report back. thanks Quote Link to comment Share on other sites More sharing options...
archiel Posted March 4, 2019 Author Report Share Posted March 4, 2019 24 minutes ago, b40rt said: Have you checked timing, not unknown for woodrough key to sheer allowing flywheel to spin on shaft, altering timing. Hi b40rt, Just quickly read up about the woodruff key and flywheel. Couldnt find much detailed information in the manual about it. Do i need the special device listed in this screenshot attached to remove the flywheel to access the woodruff key? If so, maybe this is something i can't do myself, unless theres a hack for it? Cheers! Quote Link to comment Share on other sites More sharing options...
konrad Posted March 4, 2019 Report Share Posted March 4, 2019 If you don't have a flywheel holding tool, you can use an "impact wrench" to remove/install the flywheel nut. These tools can be pneumatic or electric. See: http:// https://www.ingersollrandproducts.com/en-la/power-tools/products/impactools.html You will also need a "flywheel puller" with threads specific to your flywheel. I always lap the crank/flywheel taper with valve grinding compound to ensure optimal torque transmission. The Woodruff key is intended for location, not torque transmission. 1 Quote Link to comment Share on other sites More sharing options...
konrad Posted March 4, 2019 Report Share Posted March 4, 2019 There is another way to hold the flywheel, and that's by jamming soft aluminum between the primary gears (in fact there is even a tool made for this purpose): https://www.motionpro.com/product/08-0427 Of course, you would also need to remove the clutch housing. Quote Link to comment Share on other sites More sharing options...
b40rt Posted March 4, 2019 Report Share Posted March 4, 2019 You will need a puller, do not be tempted to try hammers / leavers etc. It will end in tears. Another way to stop flywheel rotating is get an old belt, about 50mm wide, wynd the belt round the flywheel 2/3 turns, then clamp free end to footrest. The idea is that as you start to undo the nut, the belt tights onto itself, stopping the flywheel rotating. You can tighten the nut but reversing the direction of the belt. Quote Link to comment Share on other sites More sharing options...
konrad Posted March 4, 2019 Report Share Posted March 4, 2019 4 minutes ago, b40rt said: Another way to stop flywheel rotating is get an old belt, about 50mm wide, wynd the belt round the flywheel 2/3 turns, then clamp free end to footrest. The idea is that as you start to undo the nut, the belt tights onto itself, stopping the flywheel rotating. You can tighten the nut but reversing the direction of the belt. Ohh, I like this! We call it a strap wrench in the States. But actually using a belt and clamping to the footpeg make a lot of sense! 1 Quote Link to comment Share on other sites More sharing options...
b40rt Posted March 4, 2019 Report Share Posted March 4, 2019 (edited) @archiel. If you remove the flywheel nut, you maybe able to see the end of the woodruff key / slot. This will eliminate / confirm if this is the issue. Edited March 4, 2019 by b40rt Quote Link to comment Share on other sites More sharing options...
archiel Posted March 4, 2019 Author Report Share Posted March 4, 2019 (edited) 4 minutes ago, b40rt said: @archiel. If you remove the flywheel nut, you maybe able to see the end of the woodruff key / slot. This will eliminate / confirm if this is the issue. ok cool, so i dont need any special tools to remove the nut right? Cheers guys for the help so far! Edited March 4, 2019 by archiel Quote Link to comment Share on other sites More sharing options...
b40rt Posted March 4, 2019 Report Share Posted March 4, 2019 3 minutes ago, archiel said: ok cool, so i dont need any special tools to remove the nut right? Cheers guys for the help so far! Not for removing the nut, but if you find you need to remove the flywheel, you will need a puller. The flywheel nut should be torqued up to the manufacturer's specification when you put if back on. Quote Link to comment Share on other sites More sharing options...
konrad Posted March 4, 2019 Report Share Posted March 4, 2019 5 minutes ago, archiel said: ok cool, so i dont need any special tools to remove the nut right? True, if you use the belt method. I would suggest poking a wire into the keyway slot, as it might be difficult to see if the key is there or not. 1 Quote Link to comment Share on other sites More sharing options...
mcman56 Posted March 4, 2019 Report Share Posted March 4, 2019 I once bought a 250 Techno that ran like that. It started and ran fine but lacked power. It ran sort of like a TLR200 but would rev a lot higher. When I pulled it apart, I found that the bottom of piston skirt on the exhaust side was bent in, maybe a 1/4" up from the bottom. It even had a crack but did not break off. It must have created a leak from the crankcase to exhaust pipe at TDC. I assume someone was turning the crank with the cylinder off and managed to wedge the piston into something. A new piston was the cure. I assume a shorter than stock piston could have a similar affect. An impact gun will also remove the flywheel nut without the need to hold the flywheel steady. Some people will paint a line on the nut and flywheel before removal so they know how tight it needs to be. They will then use an impact gun to reinstall to the same spot. That seems a bit risky to me so I prefer a torque wrench to reinstall. If you can drill some holes, you can make up your own "special device" that bolts to the holes used to mount the flywheel weight. Just be very careful not to thread and bolts any deeper than the thickness of the flywheel. The stator come up pretty close to the inside of the flywheel and could get damaged. Quote Link to comment Share on other sites More sharing options...
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