non fouling spark plugs for RD 350

[Still biking]

Are there any spark plugs that resist fouling on an RD350s?

[AAAltered]

Consider Irridiums.... 

[EE]

If its fouled more than one set of the proper new plugs then I'd consider the source rather than looking for "better" plugs though iridiums are nice.  Look at your mixture too rich?, over oiling, sucking in trans oil on the right, weak spark, too large a gap.

[rodneya]

Connecting a Vape ignition tom the plugs will prevent fouling as well

[Dvsrd]

What Rodney said. I haven't replaced plugs in at least 5 years and 10 000 km. Bog standard NGK B8HS. Powerdynamo/Vape is the best mod to any old 2 stroke. Period.

[Ws76133]

Back in the day, higher output coils were the solution to the chronic plug fouling.

[Dvsrd]

Back in the day, higher output coils were the solution to the chronic plug fouling.

Yes, that is sort of a solution. At least until you ride with the lights on, and have a proper H4 headlight. The stock charging system is just as marginal as the stock ignition system.

[m in sc]

its tuning and carb maintenance plain and simple IF the stock system is good shape. relying on 40 year old coils/wires/caps/condensors is not a good idea. they are a service item this far along, change them.

the stock charging system can run a 55w halogen, a car ignition, and a water pump. been there done it. zero issues. Just needs to be set up correctly. even on points bike i can leave plugs in for years.   

[Dvsrd]

In the 80s, I had 2 car coils with 3 ohm primary resistance, and a 55/60W H4 headlight on my first RD. After riding for a while with the low beam on, I would get issues at higher rpm, say over 7 or 8 K. Turning off the light would let it rev cleanly to 9.5 or 10k. This was with the stock 5.5Ah lead acid battery, charging voltage 14-14.5V and new brushes.
I still claim that a Vape or HPI CDI ignition is one of the best upgrades to any old 2 stroke Bike.
And I definitely think it makes a lot of sense to upgrade the ignition before spenning money on chambers or porting. Or even buying new coils, points, condensers, plugs, caps and HT leads.

[m in sc]

car coils draw a lot of power. I stand by what i say.  Use new replacement coils, leave the car coils in the 70's.

i also have cdis on 3 bikes, they are very good. But it is not necessary by any means.   

[Old Brit]

its tuning and carb maintenance plain and simple IF the stock system is good shape. relying on 40 year old coils/wires/caps/condensors is not a good idea. they are a service item this far along, change them.

the stock charging system can run a 55w halogen, a car ignition, and a water pump. been there done it. zero issues. Just needs to be set up correctly. even on points bike i can leave plugs in for years.   

Spot on advice right there, only addition would be to wring that sumbitch's neck a little more often 😋

[KANDY]

I bought 1975 FORD Mustang Ignition Coils and Condensers for a future upgrade (Well, I thought its an Upgrade)
So you are saying its not a good Idea.

[m in sc]

back when stock coils sucked and replacements were hard to come by, that was the go-to. i know, i did it as well.

then the emgo coils came out, they are actually british bike replacements. the mounting options suck and they really don't hold up well IMHO.

years ago, mikes XS started offering stock replacements for early xs's that were direct replacements that worked really well. that is what led to the new stock replacements that places like economy cycle sell, they are hotter than old stock coils and direct bolt-ins. so the old 'patch repairs' aren't necessary anymore.

https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/electrical-ignitions-lighting/ignition/yamaha-rd250350400-direct-replacement-ignition-coil-23-99/

https://www.mikesxs.net/yamaha-xs650-oem-type-signal-output-ignition-coil-oem-254-82310-60-00.html

or go with some dynateks.  another side note is that SV650 single lead coils are 3-4 ohm and work well as well. I run a dyna-s on my stock 70 R5, stock charging system and replacement coils and havent changed plugs in years and it runs perfect.   


this is my 1st rd. please note the down tubes.  and yes, it was very.. basic.  26? yrs ago.  and thats a drum front because i couldn't find a suitable disc front end, mine was trashed.

[KANDY]

May be I use the condensers. Dont want to repair the thing which is not broken.
Thanks m in sc

[m in sc]

the condensors are  a good option. i use ford one son my t500 actually. the bigger ones last way longer.  as an fyi, you can mount them up near the coils as well. keeps them cooler.