Would 25% Byron Race Gen 2 nitro damage my O.S. 21 VG-PX?

[Technex]

Hey guys,

Looking at getting the Byron Race Gen2 25% fuel, looks very nice although very pricy... I'm a little worried about it damaging my engine though!

Currently I'm running my stock (untouched) O.S. 21 VG-PX engine on 16% MT crap fuel but it looks like the engine has a few dots on it, even though it's never ever been over 240F and never near to lean. (I've gone through a gallon of this fuel only)

Now I'm scared like crazy that putting the 25% fuel in it would cause the piston to be covered in dots, ruining my brand new engine. Do I need to change my glowplug or add these "shims" between the head?

I'm using a O.S. #8 glowplug.

Thank you guys!

[Indie]

Hey guys,

Looking at getting the Byron Race Gen2 25% fuel, looks very nice although very pricy... I'm a little worried about it damaging my engine though!

Currently I'm running my stock (untouched) O.S. 21 VG-PX engine on 16% MT crap fuel but it looks like the engine has a few dots on it, even though it's never ever been over 240F and never near to lean. (I've gone through a gallon of this fuel only)

Now I'm scared like crazy that putting the 25% fuel in it would cause the piston to be covered in dots, ruining my brand new engine. Do I need to change my glowplug or add these "shims" between the head?

I'm using a O.S. #8 glowplug.

Thank you guys!

Of course it won't damage your engine should you tune it properly, Most racers people use 25% in their .21 engines!

[alex199020]

No, 25% will be fine in a .21. Just make sure you reset to factory needle settings and tune it again

[Technex]

Thanks guys, I just keep hearing about people using 25%+ for big block engines and -20% for anything .21 size, I don't want to take a risk at all!

I'll have to run it in again then yes?

Does this look ok, described in first post:

I'm sure it looks worse in real life . Perhaps it's just me being to scared!

Once again, not racing just bashing around for fun, want to spend as little money as possible . (some people have crap jobs)

Edited April 17, 2008 by Technex

[Mr Terminator]

Looks normal to me mate....

[Hyperhuggy]

Looks normal to me mate....

Agreed. And for the record most pro racers use 30% , so 25 % of the cheap stuff will be just fine

[Technex]

Thanks for the good news guys .

Going to for Byron Gen 2 25% Race (4 Gallon Bulk) 90 quid, ouch!

I contacted Bolton model mart and they said O'dons was being completely sold until they could get some more in from a better distributor.

So just to confirm, I'll have to break in the engine again, and retune? (nothing else?) Please reply soon, I would like to get the order in asap!

Edited April 18, 2008 by Technex

[Mel]

looks like you have got some pitting there but you should be fine. There is nothing to worry about putting Byron Gen 2 25% in though, it will more likely be better for it

[B-Master]

the piston head does look a bit pitted whihc can be down to the fuel choice or just bad maintance on the air filter just make sure you take car of the filter keep it lubed up and clean and it will be fine you just dont want it to get any worse.

i have used byron for years in my engines from cheepo engines to very high spec and neaver had a issue with 25% with regards to re-tuening/break in it really is down you but its recomeded especialy changing form MT (eww that stuff sucks)16% to a race blend

you dont need to really run in the engine you only need to back off the HSN about half a turn so its a bit richer then take it easy for 1 tank going up in % is not really a issue you will just find your engine will run cooler so just take it easy for one tank then tune the nuts out of it and enjoy

[Technex]

THERE IS?!! Model technics FUEL SUCKS! I use ARO oil evertime on my engine, air filter oil on the filter and clean the dual stage air filter every 7 tanks or so (or when dirty)....................................

I don't suppose it could be down to the tuned pipe though?!? I've got about a gap of 15mm between the header and tuned pipe.

Real annoyed now!!!

[Mel]

Nah that wouldn't cause it mate

[Technex]

Nah that wouldn't cause it mate

I've heard it can change the timing though, what else would, is it the fuel then? It's never ran to lean or in dirt etc.... I'm scared, I want to run the rest of my MT fuel today (to make room for the byron) but I don't want to damage my engine any more .

[B-Master]

with regards the the rest of your MT i would keep it i normal keep half a gallon of model tech it makes the best air filter cleaner also dont get worried about the slight pitting on the piston head this can be caused by many things 1 most common thing is when you pop a glow plug the coil form the plug can break off and cause small pitting dont worrie its ok

can you explain in more detial what you mean about the pipe having a gap ?

[snowbl!nd]

Thanks for the good news guys .

So just to confirm, I'll have to break in the engine again, and retune? (nothing else?) Please reply soon, I would like to get the order in asap!

No need to break in the engine again, although it wouldn't hurt if you did. Retune to the new fuel, there is a chance you'll have to use a cooler plug or add an extra head shim but it's unlikely.

[Technex]

Man you guys are amazing, thanks for your help!

Haha okay, I'll keep the MT fuel for air filter cleaning (it works well does it?) I've been using warm water and washing up liquid, giving it a real good dry and then applying RB oil to it.

Ah I have gone through about 3-4 #8 glow plugs during break in (ouch) my current one (#8) has been lasting agesssss though, I have 9 #8's coming soon also .

Would it be safe to get a engine shim?

What I mean about the pipe is the distance between the header and the tuned pipe, the bit with the silicone pipe. The gap adjusts the timing slightly in two strokes, it could cause pre ignition, I have no clue where to set the distance to though...

I guess if I'm running higher nitro I really want to move the distance, is it more space between them for less pre-ignition/detonation?

EDIT: Right guys ordered the Byron Gen 2 4 gallon pack and some spare front hub carriers .

Edited April 18, 2008 by Technex

[B-Master]

altering the pipes length will just effect the bottom and top end but this is very minimal on most pipes unless you get a high quality pipe thats when you will really notice the diffrance i cant rember 100% as i havent used a pip wiht the rubber adjuster but longer = more bottom end , shorter = more top but if your using the HB stock pipe ? then really the diffrance is not going to be dramatic to be honest

also you really havent said what engine you have there i am persuming its a HB .25 going by your sig

with regards o the head shim this is really no needed as most engines come pre shimed for 25% nitro content you may have to change it if you went to 30% but 25% there really is no need (wiht the HB .25)

regarding poping the plugs during break in make sure you use a HOT plug this will help stop this happening as they have a thicker coil also its best to check the condition of the plug after every tank during run in because your running it so rich they can stress and break causing internal issues. the plug coil is made from platnium (in most cases but can contain other minerals) but when you have a platnium coil bouncing around in a aluminum engine the alu is going to come off worse so always keep a eye on your plugs any sign of wear then replace them before they pop this is the cause of most piston head pitting issues.