mbeers6 Posted March 17, 2015 Report Share Posted March 17, 2015 (edited) ***Update 4/7 ....shop determined that part of the kickstart spring (end that goes into the shaft) had broken off. Problem is I don't know where it's at. Bike is still running fine so I guess I'll continue to run it unless the sound gets worse. I assume a complete tear down would be necessary to find the piece now. Anyone have other ideas, I'm open to any suggestions. I've taken off the clutch basket, idler gear, replaced kickstart spring, etc and don't see any damage to gear teeth, etc. Very frustrating. ****** Hello all, I have a 2010 TXT Pro 250 with around 150 hours on it. It just developed a slight knocking sound and I'm afraid if I keep running it, major damage may result. Bike runs fine so I'm confused. I've searched this forum for "knock" and other terms and I understand there is a common knock because of the clutch in this bikes. However for most people the knock goes away when the clutch is pulled in. Mine is a constant knock and does NOT go away when the clutch is pulled in which is why I'm so concerned. Here is the chain of events that occurred before I heard the knock: -Washed bike with light water, started and ran bike for a few minutes (no knock). -Went to remove air filter and noticed it was wet from the wash, so I took apart carb and cleaned all jets, etc. -Next time I rode the bike I hear a knocking sound. Have ridden it 4 times and knock is still there. Compared to my friends Gas Gas and mine knock is noticeable. I decidd to drain the gear box oil (running ATF) and found some metal on the drain plug. I've never had this kind of "shavings" on the drain plug. Also found some dark colored material on fill plug. So, what would you guys check first? I plan on taking the cluch cover off tonight, but what should I be looking for and how far do I need to dig into the bike? Thanks!! Video of engine running (hopefully you can hear the sound which is more pronounced at idle) https://www.youtube.com/watch?v=oxC2Ju9D598 Drain plug Fill plug Spark plug Edited April 8, 2015 by mbeers6 Quote Link to comment Share on other sites More sharing options...
totalshell Posted March 17, 2015 Report Share Posted March 17, 2015 well the spark plugs clean enough and the sump plugs dirty from old oil.. you didnt break the engine by washing it so ride it.. Quote Link to comment Share on other sites More sharing options...
sting32 Posted March 17, 2015 Report Share Posted March 17, 2015 knocking can be lean condition, wonder if you messed something up when cleaning? Quote Link to comment Share on other sites More sharing options...
huski Posted March 17, 2015 Report Share Posted March 17, 2015 Does the knock stop if you put the choke on?Cant get the video to play to hear it .Maybe the carb hasn't been reassembled right and its weak mixture is causing the knock .Idle screw wants to be about 3 turns out Go over what you've done,as the other post says washing it can't have created the noise Quote Link to comment Share on other sites More sharing options...
mbeers6 Posted March 17, 2015 Author Report Share Posted March 17, 2015 Thank you for the quick replies!! I'm at work, but will check tonight if the sound goes away when the choke is on. Currently the mixture screw is 2 turns out (where I had it before). I'm going to feel pretty dumb if its a simple carb issue Quote Link to comment Share on other sites More sharing options...
dadof2 Posted March 17, 2015 Report Share Posted March 17, 2015 It is likely a small fragment of metal like those on your drain plug has gone between the crank pinion and clutch basket gear teeth. This makes a knock like you describe. First flush the gearbox a couple of times with clean oil, just warm the bike up, no need to ride it. Then take the case off and examine the clutch basket and crank pinion teeth for anything stuck to them or any dents. Use a good light and magnifying glass. There are two probable sources of the shards of metal: 1) chips off gear teeth or dogs particularly if bearings are starting to go or 2) chips off the kickstart teeth, check these at same time you check the primary gears. Next step depends on what you find Quote Link to comment Share on other sites More sharing options...
steve_earle Posted March 17, 2015 Report Share Posted March 17, 2015 Just had a look at your video but I can't get a decent enough sound at my end. It could be the idle gear damaged by the kickstart as dadoff2 has suggested, It can suddenly happen with an unlucky kick. I gather it made that noise straight away from cold so will rule out pre ignition knock all though it looks like the head insert on the bike is a high compression one going by the red colour, They can cause knocking when the bikes warm especially if there is carbon build up in the head, they need regular cleaning to run best. These engines are simple and easy to work on, pull it apart and have a look, It's a good time to give it an overhaul anyway. Quote Link to comment Share on other sites More sharing options...
crazybond700 Posted March 18, 2015 Report Share Posted March 18, 2015 (edited) I am with above. I had the same problem some time ago.It was a part from the kickstarter gear (piece of thooth), that went trough the idle gear, trough the clutch and got stamped into the main gear on the crankshaft. Took it out and replaced idle gear and kickstart gear and problem solved. Still makes a little bit more noise than usual, need to replace the crank gear and clutch housing. (which already had some damage from another problem) Edited March 18, 2015 by crazybond700 Quote Link to comment Share on other sites More sharing options...
mbeers6 Posted March 19, 2015 Author Report Share Posted March 19, 2015 I really appreciate everyone's thoughts, very helpful! Update....knocking does NOT go away with choke on or when I richen the idle mixture screw. Okay I took off the clutch cover and didn't see any visible damage anywhere. Kick star paw had slight wear on first tooth but idler, crankshaft and clutch basket gears look perfect (see pics below). Going to have local shop give it a listen and go from there. It really sounds like it's coming from the cylinder so maybe the next step is to check piston pin, bearings, etc. When I find the problem I will post so anyone with similiar problem can reference this thread Quote Link to comment Share on other sites More sharing options...
crazybond700 Posted March 23, 2015 Report Share Posted March 23, 2015 Did you feel the bearings on the shaft where the clutch is on? The outside two look good for as far as I can see, but try to feel play. Also there is one behind in the casing ( you cannot see it). Can you feel play on the big ''axle''? A small or big end can also explain the noise. But cannot smell that from here lol. Quote Link to comment Share on other sites More sharing options...
huski Posted March 23, 2015 Report Share Posted March 23, 2015 Bet there's a tiny piece of kickstart gear embedded in one of the gears in the clutch casing .It didn't develop the noise when running but when you started it after working on it it knocked Take the clutch basket off and inspect the gear on the back of it ,the idler gear and crank gearClean all the oil off and use a magnifying glass,a.bit the size of gnats c--k will sound like the motors had it . had this problem 3 times in about 7 years Quote Link to comment Share on other sites More sharing options...
jadieki Posted April 3, 2015 Report Share Posted April 3, 2015 I'm definitely no expert, but, is there a chance you have got water into the cylinder, I got my bike very wet and dirty recently, it developed a knocking sound aswell. Sounds similar to your problem. I thought mine was something mechanical as the knock appeared in an instant like something had broken. I took it to my local dealer he changed the piston rings and cleaned it the cylinder, he said that it was wet and full of dirt. It is good as new now. Quote Link to comment Share on other sites More sharing options...
francley50 Posted April 6, 2015 Report Share Posted April 6, 2015 Jadieki, can I ask a qustion? Was the sound your engine made a bit like 'pinking'? You know, when the engine is running too lean and makes a little 'knocking' or 'pink, pink' noise when you blip the throttle?' I think mine may be doing this and wonder if new rings and a clean up may cure it. Thanks. Quote Link to comment Share on other sites More sharing options...
jadieki Posted April 8, 2015 Report Share Posted April 8, 2015 Hi francley50, without hijacking the thread. i don't think it was pinking, the knock started instantly as though something had broke. Also it was a more mechanical sounding knock if that makes any sense. Also it happened every piston stroke irrespective of throttle. Quote Link to comment Share on other sites More sharing options...
craigrevo Posted April 14, 2015 Report Share Posted April 14, 2015 Do you have any wear on the inside of the clutch cover? I have a knock coming from my engine and when I first took it apart I noticed wear on the clutch cover, but I put it down to old damage that a previous owner had repaired as there wasnt enough metal in the case to be recent. But since I have taken it apart again I decided to open the clutch pack and there was a huge amount of alloy fillings trapped in the top pressure plate. So I think that Crazybond is right about play in the main clutch bearing. Quote Link to comment Share on other sites More sharing options...
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