OS Speed piston, liner and rod

[Adrian E]

Folks

In urgent need of a new piston liner and rod for my OS Speed - the usual suspect in Hong Kong (Dinball/RC-Mart, RC-Mushroom) are showing out of stock, or just not available.

If anyone has a set they're prepared to sell at more or less HK prices then please let me know - could do with them quickly as I need to get the engine rebuilt for the last round of the summer series, or I'll be running my .28......

Thanks

Adrian

[spud]

Ade whats up with it mate

[Adrian E]

It's lost its grunt, which resulted in various frantic attempts to get it running better at the GP.  Even when 'properly' tuned it didn't pull as well as it should.  It cut during one of the heats for no apparent reason, despite a new plug, and was generally a bit lacking.

There was nothing obvious to suggest a specific problem, so I stripped it down and found the front bearing to be leaking - about enough that it might have been the cause.  Gave it to Dean to explore further and change the front bearing if nothing else found.  It's got a good seal (no blowby) but with the head off it has absolutely no pinch whatsoever when cold.  So clearly when it's warmed up it's not got enough compression to produce the power or hold a reliable tune.

The rod's actually fine, but if I'm going to rebuild it I figure I might as well do it properly.  I suspect it's seen more fuel than I think.  Have done all the summer series rounds, plus all bar the first truggy national on it, and various other bits and pieces I guess it's done more than the 3 gallons I thought it had.  A pinch might sort the liner out temporarily I suppose?

Adrian

[MR Piraterc]

I think you will find that the os engines seem to have no pinch once run in however we have a resident OS expert 

Bren should be able to assist you mate and offer some advice / guidance

[spud]

Rich is correct a good well run in o.s has no metal to metal pinch when there at there best, its all down to the quality of materials used.
TBh check the carb boot and low end o rings as these seems to wear quick.

[Adrian E]

Cheers guys

What should I be checking on the carb boot then?  Whether there's crud in there or some kind of damage to it?  I'm guessing the LSN is just a case if the o-ring is knackered?

Can these bits be obtained easily if needed?

If I can get it recovered for last meeting it'd be cool - I don't know enough from past engine experience to know if it's knackered or not....

Adrian

[spud]

tbh dude the carb boot splits and as u say needle o rings wear, if your unsure stick it in post to me, Mr Pirate and will will vouch for my superb service lol

[Adrian E]

Have asked Dean to check the above (if he hasn't already) and stick the new front bearing in - I can then have a play about it with it next weekend and see if it behaves itself a bit better.

It didn't really seem to have that OS zing when I was running it in the heats and the weird engine cut makes me think it may be fundamental wear

Am going to go count gallons of 25% in my garage - started with 6, so however many I've got left will tell me how old the Speed is......

Don't fancy running a new motor in unless we get another weekend this week as good as the one just gone

[spud]

fair enough offer there

[Adrian E]

cheers mate - have PM'd you 

[Genesis46]

Adrian, At the novarossi GP Spud was running a Vspec, and in his 1st heat it went lean on the bottom, i re-tuned it about 1whole turn richer on the bottom! on the box it will sound as rough as a dog and really rich, but after half a lap once it warmed up, it was Flying! pulling like a train Lol

[MR Piraterc]

tbh dude the carb boot splits and as u say needle o rings wear, if your unsure stick it in post to me, Mr Pirate and will will vouch for my superb service lol

I vouch I vouch

Ninja needs running in MR Pirate is now entering buggy mode whoooo

Adrian oh pal guess what I have sleeping in my radio bag " Ill give you a clue " its brand new and is off a OS engine and has some needles in it  

[Bren]

Adrian

Any odd tuning issues is normally bearings front & rear. It is well known the os runs on very little to no compression or pinch so it should be fine with amount of fuel you have used. Ive used mine that much in the past where you can hear piston rattling in the liner down the straight so they will go for ages ( this engine won badlands series so was not to bad ). The biggest killer though is water as it polishes piston & this will make it a mare to tune.
If you have old pistons & liners mix & match   this way you get a reconditioned one & a bit more life, but remember to run it in for a few tanks to bed it in.

Bren

[spud]

see the master has spoke lol

Mr pirate you know my addy put that engine in the post lol

[MR Piraterc]

I will do dude asap