Noisy engine???

[darren]

I have a GG EC250 1998

The engine has developed a dull knocking noise from the engine. It appears to be clutch side.

It only knocks on idle and low revs as soon as the engine speed increase the noise goes. When i pull the clutch lever in the noise is still there. (on idle)

I have taken the clutch plates out and inspected them also the clutch basket. Put back together filled with oil but the noise is still there.

Has any body come across this?

 

[widebear]

Could be early signs of main bearings, how many hours?Ive had similar noises and got'n off easy because ive attended to the warning signs . On one of my eary gassers i was within 10 rpm of scattering the whole bearing, the cage was half out but the balls still in it!

 

[darren]

Could be early signs of main bearings, how many hours?Ive had similar noises and got'n off easy because ive attended to the warning signs . On one of my eary gassers i was within 10 rpm of scattering the whole bearing, the cage was half out but the balls still in it!

You dont know how dissapointed i am.. just when i was lookin forward to the weekend bah..

I did ride it last weekend and when i got the bike out of the van me clutch lever had no resistance.. hence i rode it with no clutch. On returning home i bleeded the clutch and it came back. I then drained the engine oil it did appear silvery i put it down to me riding with no clutch.

I think i may have to investigate further.

Thanks for your reply I will post my findings in a few days.

 

[darren]

Sorry i dont know how many hours the bike has done. I swapped my Husky for it June last year. I have rode it every other weekend since i got it.

 

[darren]

Just took the left hand cover off the engine and spark plug out the engine turns freely with no noise or notches there is no end float in the crank and no play up or down or side to side. I know visibly this does not tell a lot but i would have thought if the main bearings were faulty it would be rumbly or notchy.

Also another thought. If the main bearings had gone or going would there be a certain amount of fuel contaminating the transmission oil? Surely crank case pressure would be lost and the engine would not run as efficiently?

Just a thought!

 

[mountain thumper]

how loud is the noise? i thought my brand new 07had a knock but it was just the pv flapping. ive read about the clutch baskets on the newer ones having some burrs that get noisy, dont know if the older ones ever had that prob or if it can be caused by wear... best of luck!! hate seein a fellow rider not riding

 

[2 strokes 4 life]

I remeber when I hopped on my Gasgas for the first time and heard the PV flapping and was scared to death what it was. Could be the engagment rod for the clutch is worn mabe.

 

[JEEPUSAURUS]

I have a '98 that sounds alot like what yours is doing, been riding it for two years like that, i always thought it was something in the clutch, but dont know for sure, also if i remember,(someone jump in here if they know for sure) the '98 has bushings in some of the trans gears instead of roller bearings, and maybe your getting too much clearance in those and getting some noise from that, i think i read somewhere about updating this.

 

[darren]

Thanks for all your replys.
Mountain thumper/
I am sure when i first got the bike there was a noise from the
clutch area this was six months ago, but it seems to be
getting noisier, it is very noticable. I suppose it could be
powervalve flapping is there any springs in there that
could brake or become weak? or any adjustments that are
needed?
The clutch basket i was told is a Talon so it is not original
when i took the plates out it did not have excessive wear.
I have bought a new clutch kit as the plates did look rather
worn. I shall try the new kit tomorrow as a matter of course.

2 strokes 4 life/
Mabe the new clutch kit may help

Jeepusaurus/
The transmission bushings may be something to look at
if the clutch doesnt work. I dont think its goin to be an easy
fix.

Plan of action.
Friday Fit new clutch
Saturday Kane round local enduro track
Next week strip engine and see what damage i have done.

To be fair the amount of money i have spent on this bike
i might as well bought a new one but i love the bike
it feels like part of me, when me bikes broke . im broke.
(in both ways)

I appreciate all of your help and suggestions.
thank you all.

 

[joey11]

From your original decription of the problem, it sounds like a problem that I had when I bought my 06 used. It would knock down low when in neutral. Put it in gear and rev it and it would go away. It ended up being the dampners in the clutch basket where it is rivited together. They apparently get tore up from aggressive clutch use as the rubber gets shredded. Jay Hall took good care of me and made it right by drilling out the rivits and replacing the dampners and then re-riviting it back together. You can check it by taking out the clutch basket and putting the small gear on the back side of the basket in a vise. Then, take the basket and try to turn it back and forth. It may take some force to turn, and it may only turn a half inch or so, but if it does, then that is your problem. I hope this helps. I ended up replacing the top end and checking the crank along with other trouble shooting before I figured it out. The sound went after this fix. Good luck.

 

[darren]

From your original decription of the problem, it sounds like a problem that I had when I bought my 06 used. It would knock down low when in neutral. Put it in gear and rev it and it would go away. It ended up being the dampners in the clutch basket where it is rivited together. They apparently get tore up from aggressive clutch use as the rubber gets shredded. Jay Hall took good care of me and made it right by drilling out the rivits and replacing the dampners and then re-riviting it back together. You can check it by taking out the clutch basket and putting the small gear on the back side of the basket in a vise. Then, take the basket and try to turn it back and forth. It may take some force to turn, and it may only turn a half inch or so, but if it does, then that is your problem. I hope this helps. I ended up replacing the top end and checking the crank along with other trouble shooting before I figured it out. The sound went after this fix. Good luck.

Thanks for that. i checked the clutch basket today. It seemed fine i put the small gear in a vice and tried to turn it by hand but it did not have any movement at all.
I have now replaced the main bearings and on receipt of me new gasket set tomozz i will continue rebuilding it..

At least once it is back to gether for my piece of mind i know it is mechanically sound in the crankcase..

thanks
darren

 

[darren]

Update.

The engine is now back together i completely stripped it and replaced the main bearings and all seals/gaskets.
All of the other bearings looked ok. i did not see any bushings in the transmission the bearings were needle roller or ball roller bearings.

I did put the clutch basket in the vice (little gear). tried to turn the clutch basket back and forth as much as i could it did not move at all.

I also replaced the pv bearings and cleaned out all carbon deposits. reassembled and checked adjustment.

The noise is still there.

I do wonder if Joey11 is correct and the clutch basket silent blocks are worn
Im a bit stumped now although piece of mind prevails that the internal bearings and components are in good order (visibly)

Does anybody know if the silent blocks and rivets are freely avaliable or do i need a new complete basket from gasgas.???

 

[Skidad]

The Gas Gas Spain site has manuals that go back to 2000 and yes the dampers and rivets are available seperately. I assume your 98 would be the same but a call to the dealer would be wise.

What is the condition of the basket anyway? Any grooving on the fingers from years of use? If so you may want to replace it as it's 11 years old now.

Did you replace the lower connecting rod bearing in the crank when the motor was appart? Hope so.

Hey, you can always replace the basket assy. with the beauty on this link. Sweet!

http://www.2tracing.it/public/SiTE/index.php?tit=Racing%20Parts&m=97&acts=|Veicoli|divGASGAS|

 

[ramcclure200]

Did you replace the lower connecting rod bearing in the crank when the motor was appart? Hope so.

If you did change the connecting rod bearing did you check the crank stuffer screws?
On my 04 200 one of the crank stuffer screws backed out and fell into the motor, when I had it apart to repair the damage you could see where it rubbed on the rod before it fell out.
It happened suddenly and I remember a knock just before it seized.
I don't know if this was a problem on the 250's or 300's but I was told that year 200 mine wasn't the first.

You can probably remove jug and piston and rotate crank and check for rub marks on the rod but so far as checking screws the crank will need to be split.

Ron

 

[darren]

The Gas Gas Spain site has manuals that go back to 2000 and yes the dampers and rivets are available seperately. I assume your 98 would be the same but a call to the dealer would be wise.

What is the condition of the basket anyway? Any grooving on the fingers from years of use? If so you may want to replace it as it's 11 years old now.

Did you replace the lower connecting rod bearing in the crank when the motor was appart? Hope so.

Hey, you can always replace the basket assy. with the beauty on this link. Sweet!

http://www.2tracing.it/public/SiTE/index.php?tit=Racing%20Parts&m=97&acts=|Veicoli|divGASGAS|

The basket itself apparently is a Talon replacement basket, fitted before i bought the bike, it is in good condition i had a good look at it checking for marks and burrs etc.

Now i did not replace the lower con rod bearing, the reason -- there was no movement or play in the bearing and the thrust was within tollerence.

Also reading by the book it stated that the crank assembly comes as one unit and could not be split. Is this the case?

 

[ramcclure200]

The crank is pressed together so you have to send the crank off to a machine shop to have them perform this task.
Maybe some one here can guide you to a good shop that is used to doing that kind of work.

Good Luck

 

[darren]

OK been out on the bike today it was running ok but then.............................a whinning noise from the engine i pulled to the side of track stopped the engine cut, now the engine will only just turn over very tight so i believe i have cooked it partial seizure bah.
when i stripped the engine last week the piston had some small scours which i wet and dried out but the ring gaps and all seemed ok.

I shall strip and find out.

 

[darren]

Well on inspection the countershaft nut has come loose and fallen behind the clutch basket.
The crankshaft nut was loose too.
Both nuts were torqued up as well looks like i will have to loctite these then the buggers wont come loose.