RVF400 NC35 ongoing problem

[micpec]

Also agreed - these plugs are rubbish when they get wet. Don't buy new ones yet - pull the old ones and stick them on the hob to Burn the fuel off. Then if you have the option ultrasonic clean them. Then try again.

Ultrasonic clean spark plugs...? Really? I never ever heard of doing that before.

[Travis]

These plugs really don't like being flooded! Some say that you can burn the fuel off with a blow torch, or on the gas hob and then get a wire brush to get all the soot off them.
As you said earlier, try the plugs from your VFR and see what's what.
P.s. Pull all 4 plugs off from the RVF at the same time, so that if there's any fuel in the cyclinders it'll have time to evaporate, then get the others from the VFR; maybe get it running for a couple of minutes, before pulling them.
Good luck!

Thanks, the odd thing is, they are SO new, Brand spanking new, I fitted them and then tried to start the bike ONCE and it flooded, so the entire life of the plug is now ruined, from being flooded once. they arent even sooty, they just got drowned in fuel, and never ignited anything so never got to the stage of what a Rich over fueling plug looks like, all blacked and sooty, these plugs look perfectly clean, they just got drenched in fuel (the thing they are designed to ignite) and this apparently killed them. Boggles the mind that a item that is literally designed to be exposed to fuel (fuel vapor at least) can be rendered ineffective from having too much fuel liquid on them. its like a gum boots that dont keep your feet dry, because they were exposed to too much water, when their entire purpose, is to be around water. The plugs are designed to burn fuel, yet the thing they are designed to be around, also destroys them. Im hesitant to spend money on plugs, so Ill go thr route of trying the VFR plugs as suggested Ill do so when they relatively warm from idling in the VFR prior. My weekend plans are developing lol.

Thanks again for the very appreciated input.

[Suzuki416]

The plugs are designed to ignite a fuel vapour not go for a swim...taking them out, hold the cap end with pliers over the hob for a couple of minutes does clean them. They are a precision instrument that has a narrow range of comfort..

[Travis]

The plugs are designed to ignite a fuel vapour not go for a swim...taking them out, hold the cap end with pliers over the hob for a couple of minutes does clean them. They are a precision instrument that has a narrow range of comfort..

ha ha, and Swim they did! nice simple explanation, appreciated :) the carbs are sorted now, so they should not swim again.

[Travis]

I bit the bullet and just went to the spares shop and picked up 4 brand new ER9EH NGK plugs, i will pop them in the weekend and revert. Im hoping you are all right, and this is just fouled plugs! Thanks again.

[micpec]

Dont forget to check the correct electrode gap before fitting the new plugs in.

[Travis]

Dont forget to check the correct electrode gap before fitting the new plugs in.

Thanks, I will do so, planning on doing this tonight, this weekend I caught up building my Ducati Pantah 500Sl, which also developed spark problems, which I since managed to fix so I had no time for the Honda. Out of interest, and exert from the Haynes Manual for VFR/RVF 400's.

"Spark MUST be a THICK blue line, if a thin yellow spark is observed, further investigation is required" So apparently even Mr. Haynes new something I didnt about RVF's" I really praying the new plugs sort this out.

I will check how the new plugs spark outside the bike before installing them, as currently i have a thin yellow spark, not the thick blue one Haynes speaks of.

[Travis]

Update: Installed new plugs, sprayed some fuel into the carb throats. absolutely nothing. Not one single hint of ignition. All plugs fire with a WEAK yellow spark. Took the same new plug, stuck it in my VFR plug lead, grounded it and observed the spark, its thick and blue. I assume this means the coils are not working properly? any advice? Thanks!

[magg]

Measure voltage on Black/White wire at ignition coils, should be same as battery voltage with ignition on and run/stop switch in RUN. If you connect the light green wire and green/white wire coming from the ignition unit to earth, you will bypass all the safety interlocks. Does this improve ignition spark?

BEWARE THE ENGINE WILL NOW START IN GEAR NO MATTER WHAT.

[Travis]

Measure voltage on Black/White wire at ignition coils, should be same as battery voltage with ignition on and run/stop switch in RUN. If you connect the light green wire and green/white wire coming from the ignition unit to earth, you will bypass all the safety interlocks. Does this improve ignition spark?

BEWARE THE ENGINE WILL NOW START IN GEAR NO MATTER WHAT.

insightful suggestion, thank you, will try this and see. at this stage im tempted to buy new coils