huge rattle from top end!


12 replies to this topic
  • wr450eff

Posted January 24, 2011 - 03:30 PM

#1

hi, i'm wondering if anyone knows of a common problem with the wr's with the top or at least it sounds like it's coming from the top end. i was in second gear, in the woods, on and off the throttle alot then i started to hear a rattle so i stopped to listen properly then it got really loud, really quick then i shut the engine off. i have since started it just for a second or two to let a couple of mates hear the noise and it runs fine and ticks over fine but with a loud rattle and a lot of vibrations through the frame. its regulary serviced and the bikes had about 4 hours use on the new oil. i could do with some tips or advice before i take the engine out. thinking about doing the work myself unless it's a lot more complicated than i think then i'll have no choice but to pay to have it fixed. any kind of advice would be helpful (and please no advice to leave it alone as i'm on a hugely tight budget and i need to try and fix it myself) thanks for reading. :thumbsup: ps the timing is still correct and the chain has the right tension and the valve clearances are ok.

  • the_smoo

Posted January 24, 2011 - 05:56 PM

#2

might help if you can provide some more info on the bike.. year etc.. also a short vid will help if you can manage it..

  • wr450eff

Posted January 25, 2011 - 04:14 PM

#3

sorry, can't supply a video, engines out now. i can't really give any more info, it's a 2004 wr 450f, i don't know how many miles it's done but i've regulary service it. i've only owned it for about 6 months but it's never missed a beat. the rattling just appeared instantly as if there was no oil in it but i drained it out just before i took the engine out and there was the right amount of oil in. i'll find out by friday whats wrong with it so i'll post a reply on here whats wrong with it. a friend thinks it the crank but it sounds like top end to me. we'll soon see. thanks for your interest and i'm gutted that i didn't think about doing a video. :thumbsup:

  • bulldog1331

Posted January 28, 2011 - 11:53 AM

#4

Make sure you let us know what the results are...everyone's bike will get older someday.

  • wr450eff

Posted February 03, 2011 - 01:31 PM

#5

i'm going to explain whats happened to my wr now that the engine has been dismantled. (sorry about spelling of mechanical parts). as the barrel/sleeve was taken of we noticed that the gudgeon pin has slid across, out of the piston about 40mm and was touching the inside of the barrel! which has obviously marked the barrel. the clip that holds it in has fell out due to the 7 month old piston having a hair line crack in thye bottom of it. we haven't opened the bottom end yet so we haven't found the clip yet. it could be down to a faulty piston??? or fitted badly when the previous owner had it, not sure. we've also noticed that one of the buckets has strange wear on it but theres no wear on the cam lobes. (new cam fitted but no new buckets???) and finally theres a little bit of play in the crank! so all in all almost a full rebuild needed spread over the next 4/5 weeks. ps 5th gear is gonna get fixed aswell!! hoping that all this work will cost around £500 as i'm on a really tight budget. any tips on running the engine in will be appreciated, i've been told to let it warm up and cool down alot and no hard accelerating for at least 500 miles! 500 miles will take me about 15 hours riding to achieve!! anyway, thanks for reading. jim :thumbsup:

  • _Hitman47

Posted February 04, 2011 - 01:24 AM

#6

Whow, that really sucks, maybe previous owner didn't replace circlips when changing piston. 0.99$ part.

So about breaking it in. put in the bike some dyno oil, let the engine warm up by riding it gently first 5 minutes and then make it scream! Go WFO and then engine break a lot. Flog the bike as if it isn't yous for first 2 hours. Then change the oil. at this point you've pretty much broken in the bike.

here is article about this method of break-in: http://mototuneusa.c..._in_secrets.htm

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • wr450eff

Posted February 06, 2011 - 03:50 PM

#7

thanks hitman. that article was really interesting. i think i'm a beleiver. it does make sense to wear the rings as soon as possible then dump the oil. gonna give it a try, i think it'll be fine. engines still in bits. starting on the 5th gear problem first then gonna work up from there. i'm going to tell the bloke who told me to run it in for 500 miles about 'the easy break-in' tommorrow and see what he thinks. anyway, thanks for the info. :thumbsup::thumbsup::lol:

  • The Spanky

Posted February 06, 2011 - 03:57 PM

#8

Whow, that really sucks, maybe previous owner didn't replace circlips when changing piston. 0.99$ part.

So about breaking it in. put in the bike some dyno oil, let the engine warm up by riding it gently first 5 minutes and then make it scream! Go WFO and then engine break a lot. Flog the bike as if it isn't yous for first 2 hours. Then change the oil. at this point you've pretty much broken in the bike.

here is article about this method of break-in: http://mototuneusa.c..._in_secrets.htm

His "ideas" on break-in are almost sensible...if all you've done is replace the rings. If you're breaking in a new piston and new bearings, all his method will do is speed up ring-seating with the trade-off of shortening the life of the rest of your engine. My engines won't be getting treated that way. Your mileage may vary.

If you think about it, the ring exerts maybe 5-10 lbs of spring tension against the cylinder wall ...
How can such a small amount of spring tension seal against thousands of
PSI (Pounds Per Square Inch) of combustion pressure ??


His supposition that the ring tension has even the most remote involvement in break-in is ignorance of how engines work to the highest degree. The rings are forced against the cylinder wall by the pressure of combustion. Those "thousands of PSI" (not hardly, but nice try) are what forces the rings against the cylinder, not the "5-10 pounds of ring tension".

Ring seating is not a complicated process, and you don't have to abuse your engine to do it. All it takes is good cross-hatching, and high cylinder pressures, which are best generated by using moderately large throttle openings while running near the torque peak. High rpms are actually detrimental to the process.

  • brentn

Posted February 06, 2011 - 05:34 PM

#9

Whow, that really sucks, maybe previous owner didn't replace circlips when changing piston. 0.99$ part.

So about breaking it in. put in the bike some dyno oil, let the engine warm up by riding it gently first 5 minutes and then make it scream! Go WFO and then engine break a lot. Flog the bike as if it isn't yous for first 2 hours. Then change the oil. at this point you've pretty much broken in the bike.

here is article about this method of break-in: http://mototuneusa.c..._in_secrets.htm


Wicked article! :thumbsup:

  • _Hitman47

Posted February 07, 2011 - 03:12 AM

#10

His "ideas" on break-in are almost sensible...if all you've done is replace the rings. If you're breaking in a new piston and new bearings, all his method will do is speed up ring-seating with the trade-off of shortening the life of the rest of your engine. My engines won't be getting treated that way. Your mileage may vary.


Not to start debate, but I don't think that piston and ball bearings need to be broken in. Pistons don't touch cylinder walls actually, thy glide on thin film of oil, and I've never heard that ball bearings need to be broken in.

Actually, afaik, there are only 2 considerations for gentle break-in: one is that tight initial tolerances could lead to local overheating and even more reduction of gap and potential seizing. and another is not to allow huge amounts of debris enter oiling system at once. I don't think that gentle break-in will anyhow wear down parts down to acceptable tolerances. Second is partially addressed by slowing down by engine braking, so that that debris could just leave with exhaust, and quick initial oil change.

The only parts that need break in, I think, are gears. And I don't see how hard break-in procedure can damage them. I'm open to any other ideas if they are argumented. Honestly, I am!

His supposition that the ring tension has even the most remote involvement in break-in is ignorance of how engines work to the highest degree. The rings are forced against the cylinder wall by the pressure of combustion. Those "thousands of PSI" (not hardly, but nice try) are what forces the rings against the cylinder, not the "5-10 pounds of ring tension".


You misinterpreted his words, that's exactly same idea he is trying to explain to the readers.

Ring seating is not a complicated process, and you don't have to abuse your engine to do it. All it takes is good cross-hatching, and high cylinder pressures, which are best generated by using moderately large throttle openings while running near the torque peak. High rpms are actually detrimental to the process.


Totally agreed! but again, no one said that rpm-s are essential. It's just easier to explain to others. Good ring seating = Biggest bang in cylinder = running WO at torque peak of your engine = (in most cases) running WO in upper range of rpms.

:thumbsup::lol::ride: motomans site is really informative, there are a lot of other publications which are really useful. read on!

http://mototuneusa.com/thanx.htm

  • wr450eff

Posted February 13, 2011 - 11:21 AM

#11

right, i'm now in two minds. first of all i have a slightly damaged barrel and a bit of play in the conrod so i'm replacing the bearings in the crank, new barrel and new piston and rings... second, i also have to replace 5th gear and a selector fork. so is it best to do the quick wear in or long wear in? surely if i go steady (meaning gentle riding with occational 'blips of the throttle') then that would be best rather than 50% saying ride it like you stole it and 50% saying stay below 3000 rpms for 500 miles???

  • The Spanky

Posted February 13, 2011 - 03:01 PM

#12

Not to start debate, but I don't think that piston and ball bearings need to be broken in. Pistons don't touch cylinder walls actually, thy glide on thin film of oil, and I've never heard that ball bearings need to be broken in.

Actually, afaik, there are only 2 considerations for gentle break-in: one is that tight initial tolerances could lead to local overheating and even more reduction of gap and potential seizing. and another is not to allow huge amounts of debris enter oiling system at once. I don't think that gentle break-in will anyhow wear down parts down to acceptable tolerances. Second is partially addressed by slowing down by engine braking, so that that debris could just leave with exhaust, and quick initial oil change.

The only parts that need break in, I think, are gears. And I don't see how hard break-in procedure can damage them. I'm open to any other ideas if they are argumented. Honestly, I am!



You misinterpreted his words, that's exactly same idea he is trying to explain to the readers.



Totally agreed! but again, no one said that rpm-s are essential. It's just easier to explain to others. Good ring seating = Biggest bang in cylinder = running WO at torque peak of your engine = (in most cases) running WO in upper range of rpms.

:smirk::lol::ride: motomans site is really informative, there are a lot of other publications which are really useful. read on!

http://mototuneusa.com/thanx.htm

Bearings and pistons don't need any break-in...yeah, OK, you run with that. :p

Like I said, my engines won't be getting treated that way. Your mileage may vary. :rant:

  • wr450eff

Posted May 02, 2011 - 01:42 PM

#13

hi, just thought i'd update my thread if anyones interested. last time i posted on TT i just had the top end off. it's now all apart and i've found the missing gudgeon pin clip in the sump. also, i've found the 5th gear problem... worn dogs on 3rd and 5th. i've since purchased all the gearbox parts for £17.60!!! and i've also purchased a brand new wiseco crank kit because mine was really on the limit so while it's apart i might as well do it and now i need the new barrel, piston and camchain. i've decided to oversize the piston and go for a full kit which makes it a wr480! which is quite cool because the cost is the same if i got my barrel done and a new standard piston. by the way has anyone got wiseco cranks or wiseco oversize pistons in their bikes?? i'm a little bit worried about putting non genuine parts in my bike but yamaha prices are crazy!!!! anyway i'll stop now. i'll post some more info when i get a bit further with the engine. thanks for reading. :thumbsup:




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.