Engine Failure

[n3il]

So was out today and after about  a tank n half she just cut out! Took her home and basically its fubard.

 

 

 

 

I cant actually see whats caused it as i cant open the bottom part of the engine as i have no flywheel puller.

 

So whats my options so far?? Cheaper the better

 

On a side note, any ideas what to use to upload photos from a ipad as photobucket is a nightmare.

 

[losi8igh]

You don't need a flywheel puller,I took my 26cc CY apart with out one.

I did a search on Youtube and found a series of videos that covered disassembly and reassembly if I remember correctly.

If the bottom end is undamaged you could just get a new head and piston but looking at that gouge in the piston/head I wonder where what did that has ended up in the engine

 

Part one of the video series.

 

 

 

In part two they use a flywheel puller but I found another video online that shows how to remove it without one. 

 

Edited August 6, 2016 by losi8igh

[n3il]

Just looking on youtube at the moment...the engine is out but iv been unable to remove the flywheel....yet lol. The conrod in my engine has about 3-4mm of sidewards play on the bottom end...is that normal?

[Oh How Original]

Judging by the dirt around the carb and the position of the gouge on the head, I'd say something sucked into the venturi.

As above, if the bottom end is okay, then a head kit will do, with some fresh gaskets and give it a damn clean lol.

[Oh How Original]

1 minute ago, n3il said:

Just looking on youtube at the moment...the engine is out but iv been unable to remove the flywheel....yet lol. The conrod in my engine has about 3-4mm of sidewards play on the bottom end...is that normal?

 

They do have a little bit of movement, not sure how much exactly is normal, but they do move marginally.

[losi8igh]

Flywheel removal

 

 

[n3il]

There are metal fragments inside the engine....just not sure where they have come from yet, nothing was sucked in carb and filter are all secure

[mike1980]

Have you had the piston off the con rod yet? The reason I ask is I have seen two cases now of engine failure with the exact same damage and both times it was the the wrist bearing under the piston that had disintegrated and got sucked up into the combustion chamber.

 

[Nitroholic]

You will have to tear down the piston/pin anyway, so you may as well.

 

Hard to tell what started this, but you have a serious bit of piston damage. Is that the ring gap in the 'gouge' or a piece of piston ring snapped away? You also have a couple of deep scores on the barrel....which all points to bits of metal hammering your motor to death. Could be the samll end roller brearing failing...needle rollers are lethal to pistons, as they are very hard steel.

 

You could rebuild with a new headkit, but I would want to make sure there were no bits lurking in the cases.

 

Flywheel comes off dead easy. Remove the nut on the end of the crank, and then just screw a bolt through each of the threaded holes....equally...and it pops off. You won;t find me taking a hammer to the end of my crankshaft.

[n3il]

Ok so took everything apart earlier and turns out it was the needle nose bearing thing up inside the piston head. On first inspection it all looked a ok, and then the rollers just fell out as the carrier part had gone.

 

 

Flywheel came off easy after watching that vid, thx Losi8igh but iv somehow managed to damage the thread, or it was already damaged... Either way im gonna need a new crank too !

 

So i guess i got some shopping to do! Any pointers for the 29cc km motor? 

 

 

[Nitroholic]

head, piston, gaskets, ring, crank ......

 

I'd seriously consider buying either a Zenoah G290 or a CY 270 and e-bay what's left of your KM motor.

 

http://www.freeprawnracing.co.uk/petrol-parts/engines/

 

http://www.innovative-rc.com/f270-4bolt-with-filter-pullstart-carb-p-784.html

 

Both good suppliers.

 

p.s. That's why I would never hammer a crankshaft end....

[n3il]

Hmmm misses would kill me if i bought a whole motor.....just been looking at CY parts instead but they dont do a 29cc 4 bolt head on innotive.

[evssv]

21 minutes ago, n3il said:

Hmmm misses would kill me if i bought a whole motor.....just been looking at CY parts instead but they dont do a 29cc 4 bolt head on innotive.

well don't tell her....or say u got it off a mate for 25 quid....and get everything sent to ur workplace.....then she never has to know what u`ve bought or not bought....

[n3il]

Haaa if only....joint bank account

[evssv]

fair nuff....

[losi8igh]

With the socket on the end of the crank shaft there is no reason for the thread to get damaged,mine came off with a very light tap with a rubber mallet.

Given how many of these things must be turned out in the factory I cant see there being and awful lot of care given in their manufacture so I don't see how one small tap with a hammer is that big of a deal.

Maybe I would think twice about hitting a £400+ engine but I wouldn't be so concerned with a single tap on a stock motor.

[dazp1976]

If it was done as per the video the thread shouldn't have been damaged at all. I've always used the same technique on many other things including 1:1 cars. Never had a problem when the nut was loosely on the end of the threads and the nut itself hit. Strange  

Never been a fan of needle bearings, they eventually escape 

Edited August 6, 2016 by dazp1976

[mark35]

http://m.ebay.co.uk/itm/Zenoah-G320-31-8cc-Longblock-HPI-Baja-Losi-5ive-/331915896042?nav=SEARCH

 

Well worth considering if you have the funds.;)

Edited August 7, 2016 by mark35

[losi8igh]

1 hour ago, mark35 said:

http://m.ebay.co.uk/itm/Zenoah-G320-31-8cc-Longblock-HPI-Baja-Losi-5ive-/331915896042?nav=SEARCH

 

Well worth considering if you have the funds.;)

 

If you were thinking of going that route I would just buy the whole engine with everything on it if it was me.

Long block is okay and you could reuse some of the bits you have already but it is a complete engine and you could keep the bits off your old one as spares.