Jump to content

jackfowler6

Bike knocking after sump smash

Recommended Posts

Evening gents,

I appologise now for my lack in knowladge mechanically! But this seems the place to ask, ive being riding my bike today i have a 2013 gas gas racing 250 factory replica i was riding for 6 hours with frequent brakes. To cut a long story short i was on my way back to van and i decided to try and hit this rock face to which i smashed the sump on the top of rock!! Straight after i did it the engine cut out and wouldnt start for 2 minits, then finally started but ran rough amd immidiatly cut back out, this happened 3/4 times and everytime it started and i applied minimal throttle it sounded like a 'sucking' noise or air was coming from the bottom of engine bear fly wheel but would cut straight back out.

Anyway i got it going but was running rough, wouldmt select gear 5 or 6 easly i had to push gear level in aswell as back at same tome to select them otherwise if i didnt push in with my bootamd just flicked up the level would just come up and not select gear. I rode bsck to van and put it in neutral and noticed with the clutch pulled in no knocking BUT let the clutch out again still in neutral the engine has an awfull knocking noise but desapears with clutch pulled in, After 10 minits i decided to call it a day after all i was nackered plus gutted there might be a hedfty bill coming my way. From what ive described what does it sound like to you guys. Ill be taking it straight to shop on monday and it will be repaired whatever the fault is but if anyone has any idea or had same problem please let me know. Cheers lads much appriciated. Jack.

Share this post


Link to post
Share on other sites
 

It is not uncommon for the frame and underside crankcase engine mounts to break on a gasgas when subjected to the treatment you describe. No point in guessing the full extent of the damage.

  • Like 1

Share this post


Link to post
Share on other sites
 
11 hours ago, dadof2 said:

It is not uncommon for the frame and underside crankcase engine mounts to break on a gasgas when subjected to the treatment you describe. No point in guessing the full extent of the damage.

No your right i could be quessing all day, i shal take it to shop monday and get it stripped and find out for certain. Cheers tho, if it is crank case mounts is it an expencive job?

Share this post


Link to post
Share on other sites
 

As I said just guesses but here goes with possible prices.

Wash bike and remove / refit engine + fluids £100

Strip and rebuild engine £150

Straighten + weld frame engine mounts £40

TIG weld (assuming cases are aluminium not magnesium) engine cases £50

Gearbox parts £50 - this only allows for the few most common worn / broken parts

If crankcases are scrap new ones are about £500 - might be able to get some seconhand.

 

Share this post


Link to post
Share on other sites
 
23 hours ago, dadof2 said:

As I said just guesses but here goes with possible prices.

Wash bike and remove / refit engine + fluids £100

Strip and rebuild engine £150

Straighten + weld frame engine mounts £40

TIG weld (assuming cases are aluminium not magnesium) engine cases £50

Gearbox parts £50 - this only allows for the few most common worn / broken parts

If crankcases are scrap new ones are about £500 - might be able to get some seconhand.

 

Thankyou for that info mate ive made a vid but wont let me upload it! Took to shop today then said its fine and im just being paranoid! So... must of being in my head but i sware this knocking wasnt there before but never mind, ill sleep better tonight 👍🏿 Cheers mate appriciate the help. 

Share this post


Link to post
Share on other sites
 
On 9/2/2017 at 1:31 PM, jackfowler6 said:

. . . and hit this rock face to which i smashed the sump on the top of rock!! Straight after i did it the engine cut out and wouldnt start for 2 minits, then finally started but ran rough amd immidiatly cut back out, this happened 3/4 times and everytime it started and i applied minimal throttle it sounded like a 'sucking' noise or air was coming from the bottom of engine bear fly wheel but would cut straight back out.

Anyway i got it going but was running rough, wouldmt select gear 5 or 6 easly i had to push gear level in aswell as back at same tome to select them otherwise if i didnt push in with my bootamd just flicked up the level would just come up and not select gear. I rode bsck to van and put it in neutral and noticed with the clutch pulled in no knocking BUT let the clutch out again still in neutral the engine has an awfull knocking noise but desapears with clutch pulled in,. . .

Problems like this rarely fix themselves overnight sitting in the shed. No disrespect intended but are you sure the shop knows what they are dealing with? 

Look under the engine and see if the bash plate is bent up against engine.  There should be some space (maybe a rubber pad to absorb some of the impact).  Pull off the bash plate and look for any signs of damage, such as cracks, bent housings or unusual gaps in the gasket surfaces. 

While reading the description, my thinking was, either: the crankcases got cracked or broken, allowing air to leak in, and moving some parts inside the transmission (thereby preventing shifting into 5th and 6th gears) and something inside the clutch cover was hitting the clutch basket, or the broken case was being hit by the crankshaft as it turned.   OR, the shift shaft took a major hit, damaging the seal on the shaft and breaking parts in the shift lever inside the clutch cover.  OR some combination of these. 

I strongly recommend you to have another knowledgeable person to make a thorough inspection of the underside of the bike and check inside the clutch cover before you ride it again.  Broken pieces inside are expensive but if they are allowed to move around they damage other parts and the repair cost goes up exponentially.

I hope I am wrong and it was just your imagination.  To me, spending another $50 to have it checked is a great investment to avoid creating a $1000 fix in the future. 

Good luck.

  • Like 1

Share this post


Link to post
Share on other sites
 
On 07/09/2017 at 11:42 PM, thats_a_five said:

Problems like this rarely fix themselves overnight sitting in the shed. No disrespect intended but are you sure the shop knows what they are dealing with? 

Look under the engine and see if the bash plate is bent up against engine.  There should be some space (maybe a rubber pad to absorb some of the impact).  Pull off the bash plate and look for any signs of damage, such as cracks, bent housings or unusual gaps in the gasket surfaces. 

While reading the description, my thinking was, either: the crankcases got cracked or broken, allowing air to leak in, and moving some parts inside the transmission (thereby preventing shifting into 5th and 6th gears) and something inside the clutch cover was hitting the clutch basket, or the broken case was being hit by the crankshaft as it turned.   OR, the shift shaft took a major hit, damaging the seal on the shaft and breaking parts in the shift lever inside the clutch cover.  OR some combination of these. 

I strongly recommend you to have another knowledgeable person to make a thorough inspection of the underside of the bike and check inside the clutch cover before you ride it again.  Broken pieces inside are expensive but if they are allowed to move around they damage other parts and the repair cost goes up exponentially.

I hope I am wrong and it was just your imagination.  To me, spending another $50 to have it checked is a great investment to avoid creating a $1000 fix in the future. 

Good luck.

Thankyou for taking the time to inform me of all the above! 👍 I took her to shop and the reson it was cutting out and running rough was the floats were stuck! Had carb fully flushed out and cleaned and shes running sweet now!! Rode today for 5 hours, think its safe to say my backs rit off haha.

Share this post


Link to post
Share on other sites
 

That is great to hear it just needed a good cleaning of the carb.  

A five hour ride is always a good day.  And certainly a good test that all is well with the bike. 

Have fun!

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

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×