Was having horrible flooding problems with my 2003 LT80 ... not only was the petcock leaking, but turns out the in-line on/off valve was ALSO leaking. So with the needle valve leaking, that was 3 failures resulting in a flooded engine and exhaust.

Rebuilt the carb (wish the kit came with the insulator o-rings too), bought a new petcock (same vacuum one) and new shutoff valve.

I think I dropped the plug because the tip actually looks like it is touching right now, so figured I would go ahead and get a new one. Well, manual says to use a BPR7HS, but the plug I pulled is a BP4HS (bought the ATV used) ... hmmm. That seems a bit hot to me although I don't know much about plugs. Looks nice and tan ...

Carb and header performance restrictions are removed (should I also remove the bolt on the bottom of the muffler?). Daughter runs pretty flat out in the sand dunes.

Any suggestions on what new plug to get?

Running mostly WOT, is it better to have a cooler plug like the 7 recommended in the manual?

What does that R (resistor) in the plug name mean?

Thanks,
Jason

 

The stock plug is indeed a BPR7HS which is fine.
You're correct, the R means ristrictor. Did you mean the "P"? It stands for pertruded.
Iridium plugs are better. BPR7HIX
On my race motor I supply a BR8HIX

 

Thanks for the reply. I have learned a lot from your posts in the past

Clearly the wrong plug was being used, but seemed to be running fine.
I guess I was hoping to learn what the "R" in the BPR7HS does since the plug I pulled did not have it.
And maybe what I could expect from running the 7 vs the 4 that I pulled.

Was running the BP4 just asking for trouble eventually? Or could it have caused any damage?

What would the Iridium advantage be?

Should the muffler plug be removed or not really make a difference?

 

Resistor= makes it so your TV don't go goofy when the quad drives by.
Iridium plugs have less resistance to the electrode thus allowing a better spark.
Pipe plug can be out or in. On a stock machine it won't make a difference.
"what I could expect from running the 7 vs the 4 that I pulled." You can expect to have the corect plug in it...LOL I don't know why someone stuck that 4 in it.

 

Thanks for the reply. I went ahead and got the Iridium plug. Have yet to put the machine back together.

The carb looked good and clean, so all I ended up using from the rebuild kit was the new float needle and seat and the bowl gasket. Below the needle, there were some flakes of metal from the casting that were barely holding on. I scraped them out, but could be that a tiny piece was interfering with the float operation.

The new vacuum petcock I got is a little different design. Does not actually have a reserve that works, well, no way to turn the dial to reserve. But, putting it on prime drains from the reserve tube. So, if we ever run out while running on "On", we can just switch to "Prime" and be good to go. One nice thing though is that between Prime and On the fuel is actually turned off. So I may try running without the inline shutoff valve for now.