Many engines fail due to a poorly seated G clip, it's a nasty job at the best of times.

the instruction manual for my engine (OS zac project) states that the crankshaft is filled with silicone & not use kerosene etc to clean, only use alcohol or fuel...could i just use my nitro fuel?

what is the best way to clean it as i dont want to remove the bearings? maybe rinse out the block & bearings with fuel & then add a few drops of common 2 stroke oil (lawnmower oil) to the bearings, crankshaft seat, crankshaft pin, conrod bearing & inner sleeve? sorry to ask specific questions...

I use Repco's "motortech" brake cleaner (AEROSOL) and give them a burst and flush the bearings, then spin up with the crank, then lube. This brake cleaner hasnt harmed the silcon yet, not sure what the brands are like in your part of the world.

im based in syd - just under your state :)

here comes a rookie question...how do the bearings & bottom end stay lubricated?
i assume that the fuel combusts above the piston (per normal) & the oil in the fuel is what dumps into the bottom end via the sleeve ports? that is, if there are oil galleries running the outer sleeve or block...

The fuel cools the block and the oil in it helps lube, no oil galleries.

( I lie, there are tiny ports in the rod and groove in the crank, another sometimes behind the front bearing.

So there is a port running to the conrod bearing and crankshaft bearings? Makes sense...ive searched google as I like to understand the mechanics of this engine in terms of lubrication but found nothing, hence my question

I've hit a snag...the head bolts on my OS are rounded...I can only get one of the four bolts out...it's a 2.5mm Allen key. Any ideas on what I can do?

I was thinking that I can heat up the engine with a hairdryer and also file down a 3mm Allen until it is a snug fit?

Also, should I use oil of some sort on the head bolt threads (once I eventually get them out) when I reinstall the bolts? The one that came out felt like it was binding and was very tight.

Thanks :)

cant believe the last owner rounded allen screws... * face palm * hope that starting with a small drill bit... you ll get the head of the screws of... etc...

tell me about - what a knobjock!
ive read the best way is to drill out the allen key caps - should be fine :)

is it worth running some type of oil on the thread bolts when i reinstall? i think they are overtightened which is why it is binding - how tight do they need to be lol...

check this out - the pics are of my IDM Ielasi engine...had this crap in it which discoloured the residue oil like a brown rusty colour & thankfully the oil was silky smooth - had a bit of surface rust on the end of the crankshaft BUT that easily came off with a simple wipe.

why did this happen & how can i prevent it from happening again? FYI, im using Maxima fuel which i run dry when im done, then i'll run the podified after run fuel (only a cap full) & run that dry.

very odd as my OS engine is like new internally...

I used a 3mm drill bit & on a slow setting i carefully drilled out the caps (i added wd40 so that i didnt burn out the drill tip) - very easy & you know once the cap came off as you can hear the pop sound :)

very happy!!!

It is not always rust. If there is a large amount of castor oil in the fuel then it can be some dryed up castor. That almost looks te same as rust.
But yes, rust is possible. The combination of wrong oil (mostly only synthetic), nitro and some moisture in the air or in the fuel can cause rust very easilly,

what are peoples thoughts on maxima fuel?

I have seen some damaged engines in one weekend.....

From using maxima fuel?
What is a good brand if this is the case? Now I'm concerned as I have 15ltrs of maxima fuel...