Spark Plug for 1990 ktm 500 cc, 2-stroke

[jurado]

Hi,

I have just restores a 1990 ktm 500 cc, 2-stroke, water-cooled. I have read somewhere that the recommended spark plug is the NGK B8 EGV, which is very much expensive than the B8 EG. I am not using the bike for competition, and just for some fun rides from time to time. Any problem / difference if I stall the B8 EG?.

Thanks. Jurado.

[frostype400]

Hi jurado, go the eg it isn't going to hurt but 8 is a fairly hot plug you may find it runs better how you ride on a eg9 or 10 slighty cooler plugs but you never buy just one plug you want to buy atleast three incase if the first goes you have 2 spares if the second goes you have a problem wrong heat range dirty filter or alike. I would buy the eg8 and see how you go thanks Michael.

[bigk]

Stick with the 8 series heat range, a B8EG will be fine, just don't use a std ES series, they are very unreliable in my experience. The "V" stands for the v shaped groove in the electrode and is the only difference in the two.
Cheers,
K

[jurado]

Thanks for the advise.

Regards, Jurado.

http://i28.tinypic.com/211kwsl.jpg

[jurado]

[jurado]

My question about the right spark plug is because a sense some sudden engine detonations when I close gas. I run the bike in a normal regime, but when I close gas, in most cases I notice one or two engine detonations. And this might be due to a wrong spark plug. Not sure. The bike seems to run and accelerate ok in all the ranges, including idling range.

The bike has a new carb, one keihin 39 pwk. They told me they jetted appropriately for my bike as per KTM advice, and installed a 55 slow jet, 175 main jet, and a ceg needle. Air mixture control screw is 1,5 turns open. 

It is rather hot here in Spain (summer time). Not sure if this might also influence.

Any advise welcome.

Regards, Jurado.

[Freakshow]

you can use the even cheaper 8-ES if you like

[Lozza]

Hola Jurado

La condición se causa cerca a mucho aire o a no bastante combustible con la válvula reguladora cerrada. Aumente el tamaño del jet lento a 60. Tengo un proyecto para poner uno de esos motores en un marco de Aprilia RS 125

[Mick D]

Hola Jurado

La condición se causa cerca a mucho aire o a no bastante combustible con la válvula reguladora cerrada. Aumente el tamaño del jet lento a 60. Tengo un proyecto para poner uno de esos motores en un marco de Aprilia RS 125

The condition is caused by to much air or not enough fuel with the throttle closed. Increase the size of the slow jet to 60. I have a project to put one of those engines in a framework of Aprilia RS 125

[TeeBone]

Thanks MICK-DE for the translation - Lozza is a cunning linguist for sure!

[Lozza]

Google translation, my Spanish extended only to sourcing a bed for the night, directions to the train station,cost of a beer and anything to do with senorita's. I was amazed how far my trusty Lonely Planet book took me but as they say that is another story

[jurado]

Thanks for the advise. Actually, the slow jet the carb has was a 52. I have a spare 55 jet and I´ll try with this one and let you know.

Regards,... Jurado.

[Mike52]

Hi Jurado
Was looking at the photo of your KTM and noticed that it looked almost the same as my old 1986 250.



What do you think?
Exhaust a bit different and rear master cyl is in a different spot but the rest looks much the same.

[jurado]

Yes, I guess most of frame, plastics, shock, front fork, etc is the same. Probably also ignition system. I have the SEM K10 ignition. Obiously, motor, pipe, etc would be different.

Regards,