Trex 600 - problems!

[waveydavey]

How about a vid with the rattling on it

[waqr]

I have changed some bearings and also replaced the mainshaft to see if this helps. Will post a video tomorrow if the rattling sound is still there.....

[waqr]

Someone mentioned that it could be the clutch hitting the top of the clutch bell. That might explain the scratch marks I have on my clutch.....

If this is the reason, how can you adjust this? The engine has fixed mounting points so to lower the engine doesn`t seem to be an option......

[pgkevet]

Someone mentioned that it could be the clutch hitting the top of the clutch bell. That might explain the scratch marks I have on my clutch.....

If this is the reason, how can you adjust this? The engine has fixed mounting points so to lower the engine doesn`t seem to be an option......

The only 'adjustments' are making sure that the hub is fully down on the crankshaft, that the clutch bolt heads are propery dogged down.. although if they did happen to be proud by a tiny bit (above the clutch rim) you could file them off a touch. I did find on one of mine that I'd left a bead of epoxy on the bell to cause a bit of binding..but that'd usually burn off fast anyway. Or some wear on the frame mounting holes. There's always the unlikely issue of a part made outside of toleranc or a buid up of threadlcok or oil and dust stopping something sitting properly. The usual answer to all these thngs istake it all apart, assess, clean and re-assemble.

Oh, and if there's an almost invisible crack in the clutch (as i had last week) then things can flex upwards

[waqr]

Well today I tried again byt the rattling noise was still there. It was like something was getting stuck and the released and the got stuck again (metal to meta). However, I applied even more throttle today despite the noise and around 30% throttle the noise dissapeared. After a few tanks there was no more rattling sound and it spooled up silky smooth. It was like it was something new that needed a short break in period.......

[waqr]

Well, today the nosie came back and after the first tank of the day the Engine refused to start. After dissasembling the motor I found this. It looks like that the bottom of the crank has been touching the bottom of the crankcase. What could cause this? The top of the piston looks like it has been sandblasted.........

[bladeboy400]

that is the bearing chipped i have one that looks like that, parts of the bearing break off and get thrown round the engine causing this damage, what bearing was mine was ceramic i now use stainless heat the casing to 120 and put the bearing in the frezzer and drop it in if you use a puller sometimes they force the bearing and cause damage. I bought a new engine, it was gonna cost Best part of a new one to fix.

[waveydavey]

I think your engine is fubarred waqr looks like the side of the piston is done and I would have thought the liner too, sorry to see that.

[waqr]

Yes, this engine will definitely be thrown in the bin

I haven`t looked at the bearings yet but I doubt that they are the cultprits. As mentioned earlier in this thread these bearins were brand new and I had this noise from tank no 1. It must have been the crank hitting bottom of the crankcase. Don`t you think so?

[waveydavey]

The only way the crank can hit the bottom is if the bush in the big end is damaged or missing or the pin on the crank is bent. From the pics yours looks okay

[bladeboy400]

it is bits of debris being caught between the con rod and crankcase the debris gets blown out of the exhaust port once the damage is done there is nothing else in the motor to go wrong unless the piston ring has broken up or the cir clip has come out when you take the bearing it will feel notchy did you use a pushing tool to put it in ?

[justfly]

Well, today the nosie came back and after the first tank of the day the Engine refused to start. After dissasembling the motor I found this. It looks like that the bottom of the crank has been touching the bottom of the crankcase. What could cause this? The top of the piston looks like it has been sandblasted.........

Yep bearing problem that, I have tried all sorts of regimes to stop the bearings from going different fuels, stopping procedures etc.. however the best solution is too just swap them out sooner rather than face this, they really don't last that long although when you think of the rpm our little engines do its hardly surprising. I don't mind regularly swapping out the bearings as I see it as routine maintenance that gives you a good chance to check over the heli.

[justfly]

Hey look on the bright side you can now drop in a 55

[waqr]

The only thing that still concerns me is this noise that came during spool up. This must have been engine related and it must have had to do with the engine failure. This noise came on my first spool up after the rebuild so it can`t have been the bearings. That is why I think something else happened that made my engine break.....

Any other ideas what it could have been? Could I have installed something in the engine in the wrong direction (crankrod etc.....)

[waveydavey]

The crank can only go one way, the con rod can go either way. The piston however can only go one way. There is a half moon cut out on one side which goes to the front, you can put this in wrong but it would jamb when you turn the engine over