View Full Version : Horrible noises from engine

04-23-2004, 08:35 AM
Hi there guys

This morning going to work my bike lost power and started to make a horrible noise, and then cut out. it restarted ok, and seemed ok, i saw the reserve petrol light on, so i pulled in to the nearest station which was only 1/2 a mile away.

Put petrol in and when the bike restarted it started make this strange whiring noise, when I got to work 8 miles later, the noise had not got better, I have pulled the transmission cover off and checked the variator nut thinking it had become loose perhaps, and it had not, but further checking revealed that the main crank bearings had play in them.

This means my engine requires a full strip down and thorough checking over.

I seem to recall somone mentioning that aprillia had upgraged the main bearing on the engine at some stage. can someone confirm this.


Joe Rubido

04-23-2004, 01:29 PM
lots of sympathy. Isn't it typical that the bearings went a few weeks after the change to 70cc and not in the weeks before when you could have renewed everything?

I think the main bearings were increased in size when the heatshield on the exhaust changed from black to chrome and the silencer box on the exhaust went from chrome to black.

i think this was probably on the site before the site revamp last year. What i have no idea about is whether you can put the later bearings on the earlier spec motor. I bought my ditech in october 2002 as a cheap price end of season sell off, and it will have the smaller bearings. I think that any machine earlier than early 2003 will have the smaller bearings. Did the change coincide with the softwear upagrade that upped the rev limit by a couple of thousand to 10800 or near offer>?

How does it feel riding the alternative standard spec ditech after the 70cc version?

Again sympathy. i would be interested to hear whether you think the failure is design or due to the pattern of use etc. i think i have overtaken you in kms over the year, but mine is standard derestricted and I have tried to keep mine under 80 kms/hr, although it spends most of its life at 70 kms plus..

04-25-2004, 01:02 PM
hi there guys

I am getting quite competent at striping my ditech, I can remove my engine unit from the frame of the bike in less than 45 min.

Striped engine down and the bearing on the variator side has lots of wear, it has been sugested by my friend who used to race karts that I should replace every bearing in the engine now thats striped down.

its possible I may need a new crank as the bearing came out with the crank and show signs of discolouring and overheating on that side.

Is any one aware if you can get upgraded/better quality bearings to replacd the OE units.

My bike has covered almost 12000 kms, and most of time at full throttle and at the maximum speed possible, the last 1500 km with the big bore kit fitted. and the last 500 of which with a TJT exhaust with the engine running at 9000/9500 rpm.

I would like to think that the failure is just bad luck as the other bearing on the other appears to be ok.

How ever its seems strange that Aprillia has decided to upgrade the bearings on the engine, perhaps they are a weak point on the engine and fitting a big bore kit and runing it at high rpm has produced the bearing failure.


Joe Rubido