oh400ex 629 Posted November 15, 2020 Hello everyone! I wanted to start a thread to document noises. Wanna start by saying that this is very perception based and a difference in how you hold the camera can give misleading information. If you are capable of posting a short video detailing either what an engine should (or should not) sound like it may be very helpful to someone in their own diagnosis. For your consideration... this is a clip of my 2000 400ex which to my ear sounds amazing. Thoughts? Please feel free to post you own proper sounding quads for consideration. Thanks for looking! Share this post Link to post Share on other sites
Fishfiles 20,145 Posted November 15, 2020 I don't hear anything that bothered me , other than maybe opening up that exhaust some , that is a Sport bike right , was kind of dark in the pic - LOL ----- SEND IT 2 Share this post Link to post Share on other sites
oh400ex 629 Posted November 15, 2020 (edited) 4 minutes ago, Fishfiles said: I don't hear anything that bothered me , other than maybe opening up that exhaust some , that is a Sport bike right , was kind of dark in the pic - LOL ----- SEND IT Oh I do. That's the bike from my "wide trail riding" video Opening up the exhaust? This thing is LOUD when opened up already. My main complaint is that the White Brothers e-series pipe is too loud. Needs to be repacked... it's on the list. Edited November 15, 2020 by oh400ex Share this post Link to post Share on other sites
AKATV 820 Posted November 15, 2020 Great idea! Had a Foreman 400 awhile back that, after a top end job, was "knocking" Having worked on engines for over 20 years, I thought I was pretty familiar with taps, knocks and piston slap etc I was fixing to pull top end off again because... you have to believe me.. this sounded like a knock for sure I put my hand down by front header pipe and you could feel an exhaust leak at the cylinder head/header pipe junction Re-seated the exhaust gasket and problem solved, quiet as a sewing machine I never had an exhaust leak sound so much like a knock/tap before Wish I had recorded it, but it just goes to show you that some noises can fool you for sure Hope to add some sound clips to help your thread soon Thanks again for a great thread idea that is sure to help people out 2 1 Share this post Link to post Share on other sites
shadetree 5,880 Posted November 22, 2020 no video ?, but i rebuilt a top end on a trx400fm years ago, started right up, then had the loudest knocking noise i've ever heard ?!. tore the head back off, seen the problem right off the bat !. some how ...do not know how or where from ???, a screw got sucked through the carb, into the intake, and got settled on top of the piston, and was getting hammered to death !!. so, word from the wise, when doing top end work ?, ALWAYS MAKE SURE ALL SCREWS ARE TIGHT ANY WHERE NEAR THE CARB..AND INSIDE THE CARB !..LOL. 3 1 Share this post Link to post Share on other sites
AKATV 820 Posted November 22, 2020 Wow that is crazy for sure you wouldn’t think it would make it through the intake valve Share this post Link to post Share on other sites
David13 84 Posted November 22, 2020 I rebuilt a van years ago, valve job and chains, two, it had a balance shaft. All done and it had a rattle in the right front wheel area. I thought for sure it was a front wheel drive axle. That type of clacking rolling based sound. Taking off the hub cab I found the hub cap was two pieces, bolted or screwed together and all the screws were loose. Rattling hub cap, that's all. dc 2 Share this post Link to post Share on other sites
