Jump to content

'14 engine grenaded - Anyone Else?

Recommended Posts

I'm an amateur rider, C class motocross.  Here's what I know (or was told) I bought my bike from a guy who was sponsored and had three practice bikes, mine being one.  His sponsor said "you gotta get rid of one of these bikes" so he put it up for sale.  He said He puts 40 hours on them, then does a top end then 20 more hours then sells them.  There was no hour meter, so I bought the bike with estimated 60h on the bottom end.  I put about 10-15 hours on it, (I change the oil every 5 hours or so) and last week during practice, my clutch cable broke.  I decided to do one more set of laps and be gentle through the gears.  I got 1/4 of a lap in and after downshifting in the air coming off a double, the bike make a horrible noise and locked up.  After taking it apart we see that the rod broke (not sure what caused it) and it broke just about everything else in the engine, stabbing holes in the case, transmission and head.  I'm horrified and really upset that my new to me bike would do this! 

I've had an '07 KX250f for years and never had such a problem, and am now really wondering if I should have bought a YZ.

 

A guy a Pro-Circuit Racing told me that they do complete rebuilds every 30h for beginner riders 15h for pros, they don't do just top ends on these bikes and that the rod is the weak point. That sounds crazy to me - I thought I could get 70-100h before a complete rebuild.  Am I wrong, are these bikes that fragile?  Has anyone else had such experience? 

Edited by Ibanezsvo

Share this post


Link to post
Share on other sites

I have the same bike. 2014 kx250f. Bought mine brand new. Would change the oil every 4 to 5 rides. Did top ends about every 25 to 30. Put about 100 hours on it and it blew on me. the bottom end of the crank blew through the cases. Destroyed my cylinder but the cylinder head and valves look to be good. I just bought a used engine with 2 hours on eBay for 1,650. Engine looks brand new to me everything about it seemed good so far. So I bought a new engine instead of taking the time to rebuild my OE engine and was back riding in about 2 weeks

Share this post


Link to post
Share on other sites

I have the same bike. 2014 kx250f. Bought mine brand new. Would change the oil every 4 to 5 rides. Did top ends about every 25 to 30. Put about 100 hours on it and it blew on me. the bottom end of the crank blew through the cases. Destroyed my cylinder but the cylinder head and valves look to be good. I just bought a used engine with 2 hours on eBay for 1,650. Engine looks brand new to me everything about it seemed good so far. So I bought a new engine instead of taking the time to rebuild my OE engine and was back riding in about 2 weeks

i hate you, i was about to buy that and you beat me to it....

Share this post


Link to post
Share on other sites

Sorry to hear the horror stories of 4 strokes. Those stories are why I ride 2 strokes . Pretty easy to work on and cheap.

Good luck fellas

Share this post


Link to post
Share on other sites

Wow you saw that one on eBay too? It was a good deal. I was talking to another guy who had a 2011 engine. Stock bottom end but has pro circuit valves. Cams. Springs and ported and polished for 1,700 has 25 hours on whole thing. I am a 250 novice also and wanted to get that engine but wasn't sure if it would fit a 2014

Share this post


Link to post
Share on other sites

I bought my 13 from a racer that used it as a practice bike. At 50 hours he put his top end in , I put another 50 hours and put my new top end in it. Never have touched the bottom though , now. I know a guy why puts in a new top end every 15 hours and bottom 30 hours. I can't afford to do that though , it's just not economical

Share this post


Link to post
Share on other sites

I'm an amateur rider, C class motocross.  Here's what I know (or was told) I bought my bike from a guy who was sponsored and had three practice bikes, mine being one.  His sponsor said "you gotta get rid of one of these bikes" so he put it up for sale.  He said He puts 40 hours on them, then does a top end then 20 more hours then sells them.  There was no hour meter, so I bought the bike with estimated 60h on the bottom end.  I put about 10-15 hours on it, (I change the oil every 5 hours or so) and last week during practice, my clutch cable broke.  I decided to do one more set of laps and be gentle through the gears.  I got 1/4 of a lap in and after downshifting in the air coming off a double, the bike make a horrible noise and locked up.  After taking it apart we see that the rod broke (not sure what caused it) and it broke just about everything else in the engine, stabbing holes in the case, transmission and head.  I'm horrified and really upset that my new to me bike would do this! 

I've had an '07 KX250f for years and never had such a problem, and am now really wondering if I should have bought a YZ.

 

A guy a Pro-Circuit Racing told me that they do complete rebuilds every 30h for beginner riders 15h for pros, they don't do just top ends on these bikes and that the rod is the weak point. That sounds crazy to me - I thought I could get 70-100h before a complete rebuild.  Am I wrong, are these bikes that fragile?  Has anyone else had such experience? 

 

Some go forever and some don't last 10 hours.

I rebuild these for people all the time for the same reason as yours

The good news is the head usually doesn't take a hit and the parts are fairly cheap. I would recommend rebuilding over buying a used motor.

You can get the major parts for less than $1k, depending on how many trans gears get wacked.

Its a pain swapping the bearings from the old cases to the new, but Hotrods supplies case bearing sets now so that makes it easier.

Its an unnecessary expense to buy new bearings though

 

 

 

http://www.ebay.com/itm/Cylinder-works-Standard-Bore-Cylinder-kit-11-14-KX250F-30006-K01-/321854705255?fits=Year%3A2014|Model%3AKX250F&hash=item4af0090e67:g:C5AAAOSwo0JWM9cO&vxp=mtr

 

or go for a big bore for more fun

 

http://www.ebay.com/itm/2011-2014-KX250F-3-MM-269cc-Cylinder-Works-Big-Bore-Kit-13-5-1-Kawasaki-/322000410901?fits=Year%3A2014|Model%3AKX250F&hash=item4af8b85915:g:4ZkAAOSwq7JT1t78&vxp=mtr

 

http://www.ebay.com/itm/HOT-RODS-CRANK-CRANKSHAFT-ASSEMBLY-4021-KAWASAKI-KX250F-2011-2015-/231771072290?fits=Year%3A2014|Model%3AKX250F&hash=item35f6a1e722:g:GVwAAOxy-WxTDLo2&vxp=mtr

 

http://www.partzilla.com/parts/detail/kawasaki/KP-14001-0605.html

Edited by nesc103y

Share this post


Link to post
Share on other sites

It all boils down to how hard you ride. Trail riding a motocross bike and you will easily make 60-80 hours on a crank. Full throttle racing on a motocross track with big up hills and sand and you are pushing your luck at 25 hours. When I hear about these 300 hour cranks the owner is either full of BS or one hell of a slow rider!

Share this post


Link to post
Share on other sites

Wow you saw that one on eBay too? It was a good deal. I was talking to another guy who had a 2011 engine. Stock bottom end but has pro circuit valves. Cams. Springs and ported and polished for 1,700 has 25 hours on whole thing. I am a 250 novice also and wanted to get that engine but wasn't sure if it would fit a 2014

 

 

That's my 2011 Pro Circuit engine for sale.

Share this post


Link to post
Share on other sites

My sons a B rider but stays off the rev limiter. His thrust washers went out on the crank at 42hrs. So we did a complete rebuild. Other then that its been bullet proof and still runs better then any bike weve owned

Share this post


Link to post
Share on other sites

My sons a B rider but stays off the rev limiter. His thrust washers went out on the crank at 42hrs. So we did a complete rebuild. Other then that its been bullet proof and still runs better then any bike weve owned

how does a thrust washer go out?  Thats the washers around the needle bearing that are used for pushing the clutch basket in and out right?  what are the symptoms?

Share this post


Link to post
Share on other sites

how does a thrust washer go out?  Thats the washers around the needle bearing that are used for pushing the clutch basket in and out right?  what are the symptoms?

These are on either side of the crank. It just started making this wierd vibration noise then quit next to the truck. Open up oil filter to find little bronze looking chips in the oil.

Share this post


Link to post
Share on other sites

WOW! How lucky you got! Catching it so early.  I usually wear headphones while I ride so I don't ever hear funny noises from the bike.  After this I will likely stop doing that - at least some of the time to listen to the bike a little more. 

Share this post


Link to post
Share on other sites

WOW! How lucky you got! Catching it so early.  I usually wear headphones while I ride so I don't ever hear funny noises from the bike.  After this I will likely stop doing that - at least some of the time to listen to the bike a little more.

k

Yea it was pretty annoying. I was mad at my self thou cause i keeped trying to start it. It runs better then ever now and we put a brand new OEM crank back in it rather then rebuild that one

Edited by spin05

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×