Microlighters

I went flying for 30 minutes this afternoon, landed at a farmer friend's field and just could not get the Rotax to start again. It started, spluttered and died. Then nothing. After cleaning filters, jets etc. my friend suggested spark plugs. I thought not as they only had about 5 hours on them. On closer examination I saw they were BPR8ES plugs not BR8ES. Does anyone know if the BPR8ES plugs will have done any damage to the Rotax?

I fited spare BR8ES plugs I always have with m and flew back to the with seconds to spare light wise. After landing I tried the Rotax and it started no problem every time.

Ok, here goes:

"B" = 14mm thread. Self explanatory.

"P" = Projected insulator tip. Have a good look at the two types of plugs side by side. You will see that the BPR has a slightly longer insulator tip than the BR. This Projected tip will be approx. 20ºC hotter than the normal type. This 20º relates to the TIP of the FIRING end of the plug. It has nothing to do with the HEAT RANGE of the plug. (That's another lesson :D ) What this extra heat at the firing tip does is help to burn off carbon, UNLESS the firing tip is hotter than 850ºC, then some damage to the engine MAY occur due to pre-ignition and/or detonation. An engine that is already running on the lean side, in conjuction with a projected style insulator tip is BAD NEWS. If you did have overheated spark plugs you may notice the ceramic around the center electrode is blistered/cracked and/or even melted. Inspect the plugs carefully. If they look no different to the other ones then, I wouldn't worry too much other than pulling the exhaust manifolds and inspecting the pistons through the ports.

"R" = Resistor type plug.

The short answer to you question is "yes". It can do damage to the engine especially if the engine is already running on the lean side.

Duck Rogers

DR

Looking at you one wouldn't guess your such a bright spark :D

Duck Rogers

Hey die gans is nie te bad nie!!

Ok Duck, spit it out.

What shuld the gap clearense be on the BR8ES for a 503 Rotax Motor

So dik soos n lekker cherrie se vinger naal.

OK Enough, enough!! My very serious question has degenerated into a real k@kpraat thingie!! :D :D :D

I changed plugs back to the correct BR8ES and voila! the engine starts, sounds, flies like it used to. Amazing the difference plugs can make.

Next question though. On the BR8ES box I bought at Autozone there is a drawing of a microlight with a big red cross drawn through it as well as an exclamation mark. Apparently Aviation Engines agrees and says we should buy Rotax BR8ES plugs? What can the difference be and does anyone know if it is dangerous to fly on these plugs? We have all been using them for years and do not seem to have picked up any problems.

[quote="Robin Hood"] On the BR8ES box I bought at Autozone there is a drawing of a microlight with a big red cross drawn through it as well as an exclamation mark. Apparently Aviation Engines agrees and says we should buy Rotax BR8ES plugs? [quote]

........ ............. .No you tell me

Hallo daar Bennie

I know a gent who flies thses plugs in his fixed wing, uses the 2-stroke from the closest garage BUT he does do the plug changes on time and he does care for his engine and it has never given ANY problems in more than 400 hours!! Nie n hoes poep of slputter nie, laat mens dink ne
san

Bennie Boekwurm wrote:What shuld the gap clearense be on the BR8ES for a 503 Rotax Motor

The recommended gap is 0.38mm - 0.48mm. Some will say 0.50mm. I set mine at 0.48mm.

Duck Rogers

Robin Hood wrote:...On the BR8ES box I bought at Autozone there is a drawing of a microlight with a big red cross drawn through it as well as an exclamation mark. Apparently Aviation Engines agrees and says we should buy Rotax BR8ES plugs?....

It depends what you bought? Champion or Made in Hong Kong? Then I agree.
Otherwise, in plain Afrikaans.......K@K!
NGK is NGK is NGK.......

Someone prove me wrong....?

Duck Rogers

These were genuine NGK - check the box, they are marked not for Microlights. I kid you not.

I don't doubt you one bit. I have seen it also.
I have used them before and my Rotax doesn't know the difference...if there is any

Duck Rogers

Thanks Duck

You are a well of knowledge