CRF250 engine noise
  • scooterbikes
    Posts: 15
    Joined: Thu Jun 30, 2016 5:46 am

    CRF250 engine noise

    by scooterbikes » Thu Jun 30, 2016 5:54 am

    Hey everyone first post on here. I have been struggling with at '04 250 engine noise. Bought bike not running awhile ago finally got to rebuild. I put a Hot Rods stroker crank in, new cam chain, new SS valves/springs/seat cut, new manual cam chain tensioner.
    Still have this noise: https://www.youtube.com/watch?v=XOnMt3z_hpo

    Ideas?
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    by JimDirt » Fri Jul 01, 2016 11:35 am

    Welcome to the site !! \:D/

    It kind of sounds "normal" to me , maybe a slight bit of timing chain slap , you said you have a manual tensioner , could it be you have the adjustment off ?? , it sounds like the chain may be a little loud , but other than that , i don't hear anything real strange , but videos are always hard to distinguish sounds from because most of the time the speaker system is "tinty" sounding anyway , being in a room that is fairly empty will make sound amplify as well , as will being on concrete , try running it on the lawn and see if its as loud .... Question , do you have a Aluminum Skid Plate ?? , i could not tell from the video as the camera did not go low enough , a Aluminum skid plate will reflect engine noise (any skid plate will , but the aluminum will make it resonate more , so it is louder) , thats the only other thing i can think of by listening to it

    These engines are not "quiet" internally , just the nature of the beast , if you listen to any other 4 stroke , they will be noisy as well , if you are away from the exhaust noise you will hear all sorts of things clanging around , its when they get real loud is when you start to worry
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    by Aussiecrf230 » Fri Jul 01, 2016 4:58 pm

    +1 with the aluminium skid plate reflecting noise. When I put one on it sounded like the rocks were already in there.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • scooterbikes
    Posts: 15
    Joined: Thu Jun 30, 2016 5:46 am

    by scooterbikes » Mon Jul 04, 2016 6:44 pm

    JimDirt wrote:Welcome to the site !! \:D/

    It kind of sounds "normal" to me , maybe a slight bit of timing chain slap , you said you have a manual tensioner , could it be you have the adjustment off ?? , it sounds like the chain may be a little loud , but other than that , i don't hear anything real strange , but videos are always hard to distinguish sounds from because most of the time the speaker system is "tinty" sounding anyway , being in a room that is fairly empty will make sound amplify as well , as will being on concrete , try running it on the lawn and see if its as loud .... Question , do you have a Aluminum Skid Plate ?? , i could not tell from the video as the camera did not go low enough , a Aluminum skid plate will reflect engine noise (any skid plate will , but the aluminum will make it resonate more , so it is louder) , thats the only other thing i can think of by listening to it

    These engines are not "quiet" internally , just the nature of the beast , if you listen to any other 4 stroke , they will be noisy as well , if you are away from the exhaust noise you will hear all sorts of things clanging around , its when they get real loud is when you start to worry


    Thanks for the reply guys. No skid plate at all. My YZ450f is no where near this loud, I do not recall other CRF250's I have been around being this loud but I will see if I can get around some.

    Have the counter bearings coming in, about the only other thing not new in the engine so why stop now.

    FYI Video was shot with auto tensioner still in and with manual one I cannot get it to quieten down.

    will get at it again this weekend. Thanks.
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    by JimDirt » Mon Jul 04, 2016 11:02 pm

    Generally if the noise is not from a skid plate , then i would think you have a issue with the timing chain or tensioner , or maybe the guides for the timing chain are worn , the valves are not too loose are they ??? (did you double check the valve lash ??) , there is not a lot it could be , especially if everything is new , it kind of rules out the items we are talking about , but , the tensioner can still be a issue even if its new , but since its the old one in the video , then again , it kind of rules out the parts that are subject to scrutiny

    The only thing i would recommend is to go back over each item , and double/triple check to rule each item out

    Could it be a clearance issue with the stroker crank/rod ??? , maybe hitting the base of the cylinder ?? , it may necessitate a teardown to trace the noise , which could be from the crank/rod hitting.......that is my suggestion , there are a few things that could be a issue , and the only way to know is to positively eliminate each item
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • scooterbikes
    Posts: 15
    Joined: Thu Jun 30, 2016 5:46 am

    by scooterbikes » Sun Jul 10, 2016 10:36 am

    I think I found the issue. Have not torn it down yet but assume this is it https://www.youtube.com/watch?v=5wXs0bembTs
    Exact same noise....my eff up. Gasket kit on the way. I think I put the piston in the same way Honda does, they have a IN stamped on the piston Wiseco uses a arrow ^ which indicates exhaust side. Will tear down and confirm but I was leaning and am 95% certain its the piston in wrong.
    :oops:
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    by JimDirt » Sun Jul 10, 2016 12:25 pm

    Hmmmm , usually its easy to tell what side goes where on a 4 stroke piston with or without a arrow or marking , they have notches/reliefs for the valves , the larger are Intake side , to coincide with the larger Intake valves, the smaller coincide with the smaller Exhaust valves , so its usually hard to get it mixed up , but sometimes in haste to get it back together things get overlooked

    Not the first time i have heard of this happening , but its not common to do it ..... hopefully nothing got damaged in the time it ran and you will be able to reverse it and get it running again (once you confirm that it is in fact reversed) , check the skirt for any damage/cracks , wear , etc , you don't want to put it back together and have the piston skirt break off and cause serious damage ...
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • scooterbikes
    Posts: 15
    Joined: Thu Jun 30, 2016 5:46 am

    by scooterbikes » Sun Jul 10, 2016 12:45 pm

    JimDirt wrote:Hmmmm , usually its easy to tell what side goes where on a 4 stroke piston with or without a arrow or marking , they have notches/reliefs for the valves , the larger are Intake side , to coincide with the larger Intake valves, the smaller coincide with the smaller Exhaust valves , so its usually hard to get it mixed up , but sometimes in haste to get it back together things get overlooked

    Not the first time i have heard of this happening , but its not common to do it ..... hopefully nothing got damaged in the time it ran and you will be able to reverse it and get it running again (once you confirm that it is in fact reversed) , check the skirt for any damage/cracks , wear , etc , you don't want to put it back together and have the piston skirt break off and cause serious damage ...


    Not the piston....didn't think I would have screwed that up but dumber things have happened.
    Will continue tear down and case split to find it.
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    by JimDirt » Sun Jul 10, 2016 8:31 pm

    Well , at least you eliminated one thing , you can look at it that way , your positive on valve adjustment correct ?? , triple checked ?? , back to timing chain , did you check the tab at the bottom (behind the flywheel) that keeps the chain from falling down off the lower sprocket ?? , it is possible to have bent it , and it might be rubbing on the chain ....just something else to check while your in there
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • scooterbikes
    Posts: 15
    Joined: Thu Jun 30, 2016 5:46 am

    by scooterbikes » Tue Aug 23, 2016 12:33 pm

    JimDirt wrote:Well , at least you eliminated one thing , you can look at it that way , your positive on valve adjustment correct ?? , triple checked ?? , back to timing chain , did you check the tab at the bottom (behind the flywheel) that keeps the chain from falling down off the lower sprocket ?? , it is possible to have bent it , and it might be rubbing on the chain ....just something else to check while your in there


    OK....so I hate finding my problem on a thread here then it ends with the poster stating I am going to try fix X and no one ever posts if it works or not.

    So here it is.
    I have been busy with work and other non dirt related problems. Tore it apart last night and found the shim from the water pump shaft had fallen out during assembly. It lodged itself under the shifter linkage which explains my other less intense issue of the shifter not wanting to center after a shift. The water pump shaft and impeller would now have room to shift side to side and with my fingers I can almost recognize the rattle from the vid. It also explains why when I pulled the spark plug and turned the engine over there is no sound at all. 90% positive its fixed. Will reassemble and confirm on here.
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    by JimDirt » Tue Aug 23, 2016 12:53 pm

    Well at least you were persistent and continued looking , and actually found things wrong (that's a good and bad thing), hopefully this is all it is , and you can get back to riding , never thought that noise would be originating from the water pump though ... :?
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • scooterbikes
    Posts: 15
    Joined: Thu Jun 30, 2016 5:46 am

    by scooterbikes » Tue Aug 23, 2016 4:53 pm

    JimDirt wrote:Well at least you were persistent and continued looking , and actually found things wrong (that's a good and bad thing), hopefully this is all it is , and you can get back to riding , never thought that noise would be originating from the water pump though ... :?


    No kidding me either, but I have checked the valves so many times my feeler gauge is getting worn out LOL. Its pretty hard to screw up the bottom end and I do know I pulled that cover off after assembly to check the some stuff when engine was back in the bike, thats likely when I screwed up....lesson learned there. I have balancer bearings going in tonight and back in and hopefully get it running again tonight....fingers crossed. Have a hare scramble coming up this weekend and my 450 is a killer on this race...tight and twisty.

    Thankfully my old 450 still runs like a top so I wasn't completely off the dirt.
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    by JimDirt » Tue Aug 23, 2016 9:00 pm

    I envy you :cry:

    I had my suspension sitting on the bench for the last month trying to figure out which way to go on the valving , when i finally decided on what i wanted to do ,and got it put it back together after the changes and i went to practice (on the 13th),, i loved how it felt....then i wadded it up bad enough on a crappy built jump , to shatter the end of my arm at my wrist and dislocate my hand severely , then had to have surgery actually on my 57th B-Day (last Tuesday) , so unfortunately i am going to be off the dirt for about a year myself , in fact i go see my surgeon tomorrow for a follow up to see how it looks a week after surgery , i was so looking forward to riding and racing more this year , now i am mostly on the couch in pain , i just stare at my bike that amazingly , is in far better shape than i am right now , (it sucks trying to do everything with one hand)

    ** it was my left hand/wrist/arm i hurt/broke and of course i am left handed** :cry:

    Good luck and i hope your back to riding after you get it put back together , and your troubles and frustrations are behind you .... ;)
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    by Aussiecrf230 » Wed Aug 24, 2016 8:07 pm

    Most importantly thanks for the feedback on what you found. Fingers crossed for you that it is only problem. We have all made mistakes in a rush.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • scooterbikes
    Posts: 15
    Joined: Thu Jun 30, 2016 5:46 am

    Re: CRF250 engine noise

    by scooterbikes » Thu Apr 27, 2017 7:43 am

    So long story short. I rode the season out on my 450, now being a procrastinator I am back on this thing.
    I put everything back together late last fall, started and had the same thing going on with noise, maybe not quite as much noise
    hard to tell.
    I think it is definately a valve train issue so taking it in to a shop this week, I can't see guides being that horrible but who knows. I have to either get it running properly or convert it to the CR500 engine I bought off ebay last fall after being pissed off and browsing with an itchy bid finger. :-~
    Should have spent that money at the shop and got this thing fixed properly. ](*,) oh well, will see....

Who is online

Users browsing this forum: No registered users and 4 guests