Re: gears
 

How long is your straight? Usually the stock gearing 17/22 pinion and 60/56T spurs is plenty enough for most tracks. The tallest 2nd gearing is 23T pinion and 55T spur which has an FDR of 4.48.

track
 

the track is a 280-300 ft straight but wat is the tallest gear o get so i can have top end?

tallest gears to get? sorry for spelling

Re: track
 

The tallest 2nd gearing is 23T pinion and 55T spur which has an FDR of 4.48.

:( Avoid to blip the engine in full throttle too much/ too long on the starter box.

:nod: What I usually do is not rev the engine for the first 30 seconds of starting or so on the starter box. I let it idle and then slowly start to rev the engine.

I'll check, but I would be afraid to replace the major components and then find that the crankcase is also damaged, resulting in all the new parts being damaged.

As I've got a JP FX on its way, I'll replace it with another JP . It seems the JP is actually based on the Novarossi/Novamega design - I wonder if it uses the same conrod?

I think the crankshaft must have been damaged, but when I put it in the engine and spun it, I could see no deflection at the end of the crankshaft :confused: But it may have been a very small deflection. This is borne out by the fact that the engine seemed to work "fine" for 5 tanks and then blew on the 6th :(

Yep, there are scratches on the backplate - which weren't there yesterday.

And the liner is where a lot of technology/research is invested - which is reflected in it's price! :nod:

Crankcase damage? That would almost be impossible. I think you meant crankshaft...

Yeah, you're right in saying that. If a major damage like this happens, usually better to get a new engine.

Perhaps can you take a pic of the piston / liner condition after cleaning it? There is a chance that they can still be used.

If you got the FX engine, I would not know if they have the same internals having same dimensions as the Novarossi / NovaMega. Hope Schrijver99 or someone else can shed some light on this.

JP came out with their own line of FX engines but had Novarossi make them to their own specs. I know in the previous times, what JP does is get Novarossi engines and do their own "mods" on them and sign them off as modded JP engines.

I checked the bell, too. I mounted it as normal, so it was pretty near the clutch and span it - it seemed to spin smooth and straight and still does :confused: But when I have a look at the metal shielded bearing nearest the engine end - it has been rubbing the clutch bell, as around its circumference there are three "rub" stripes, i.e. it has been rubbing the inside of the clutch bell - that should never happen. I think the hit bent the clutchbell or crankshaft to such a small degree that it is impossible/very difficult to see the resulting damage, but at +35,000 revs, the forces generated by the wobble caused the bearings to slowly disintegrate.

Could be. But most of the time, the crankshaft is bent where the Centax clutch is installed. The part inside the engine is pretty think and not like to bend. A bent crankshaft would usually result in the spurs / pinions stripping out of no where. Engine also has excessive vibrations when you rev it. And these vibrations are no good to the front and internal bearing as well.

I guess the bushing was also waiting to disintegrate as a result of the accident.

Ummm, so the crankshaft was somewhat pushed to the other side which hit the backplate and dislogded the conrod in the process...

The conrod bushing(big end) blew up first then anything goes wrong.
Should be no problem with centax assembly. Just my observation.

Kawada SK-18 Bearing Cleaner Case for about USD8

The crankcase is damaged in the area where the conrod mates to the crankshaft - as the bearing disintigrated, the conrod came away from the crankshaft and damaged the crankcase.

I see a lot of micro-scratches in the liner and on the piston head - I'll try and post some pictures.

Certainly the JP website shows that the engine has the same dimension as the Nova series - then probably the parts are exchangable. My suspicion was that they have made a lot of work in the liner deparment - the conrod seems to be the same anyway in all the 12 series engines, so it doesn't seem to play any part in performance. I'll let you know when I find out, though :nod: