BS34 Carb pilot jet plug

Hello all, newbie to this forum, but i had something that I wanted to everyone know.
The plug under the idle jet is a must, just found out the hard way. Bought the bike about four years ago, has never run right, i've changed alot of things on this bike before i found out tonight that the plugs were supposed to be there.

I just cleaned my carbs and removed the pilot jet plugs (and threw them away); it runs great below 4,000 rpm, but above 4,000 rpm when I give it more than 1/2 throttle, it breaks-up/misfires; I put in new spark plugs and the tips are white, so I'm thinking its lean due to air leaking via the intake boots (I ordered new ones). I would think if I had a problem due to removing the the pilot jet's plugs, it would show up at start-up, idle, below 4,000 rpm, etc., not at high rpm. Why do you say the pilot jet plugs need to be there? How would the gasoline get thru with them there? Do you think that could be my problem above 4000 rpm? Thanks for this post.

replace your rubber plugs it sounds to me like all your problems started right after you removed them the two things may be related, maybe. if it was your intake boots it would be lean at idle and and not return to idle very easily. rpm's would hang up.also the warmer the bike gets the worse the problem would be.

That's the same as my bike was doing. When i bought the bike the plugs were not there, I made plugs from a lead sheet and it runs oh so much better. Inside the hole whre the main jet goes there is a hole that feeds the pilot jet, that is how gas gets to the pilot jet, with out the plugs the gas gets sucked through that hole which is above the main jet & floods the engine on anything above half throttle. Hope this helps, just thought i would post with my personal experience of the same situation.

Dern, I've been running mine since July with no plugs.


I hope i can get some from Jeff. Roy

I've read on here some where that some of these carbs can run fine with out them, but the ones i have will not, so if the bike is running good then i probably might not worry about it. My bike would not rev & the plugs were always very black.

I'm going to pull the head this winter and i will go through the carbs also. I'm running 40/140 jets. Roy

not trying to be a smart ass. but, why would someone tear apart their carbs and then discard internal parts???

roy-b-boy-b wrote:

Dern, I've been running mine since July with no plugs.

I hope i can get some from Jeff. Roy

Roy, I mailed Jeff about these plugs recently - they do carry them, temporarily out of stock but they should be getting some soon.

Here's a link.

morningwood wrote:

not trying to be a smart ass. but, why would someone tear apart their carbs and then discard internal parts???

because I'm an idiot. The bike runs great at lower RPM and starts instantly; I can't even touch the starter quick enough for it not to start, even when it's 35 F outside (and no cold stumble...wish my harley ran like that), so I didn't even think high RPM issues could be due to the pilot plugs (which I though I read on-line should be removed...didn't see anything about putting them back...thought they were EPA mandates...). I put new carb body screws in and after about a week, just threw away the plugs along with the old screws. It was until I read spdrcr9's post that I even thought about them again (thanks a bunch spdrcr9!). However, I ordered 4 new pilot jet plugs and their o-rings from Ron Ayers ($35 delivered), so at least I'm able to get new ones.

again not trying to be a smart ass. every part is a cost to the manufacture. so if the part is present, then there is a very good reason for it being there. just my two cents for what it's worth.
oh, almost forgot to point out. the o ring end of the plug goes in first. if you install the plugs wrong you can NOT remove them easily. to do that will be a major PITA.

Thanks. I would agree in general; it's not the case here, but I would think there are some governmental mandated items that the manufacture would just as soon leave out; the pilot screw plug comes to mind. Re: putting the plugs back in, can't the plugs only fit in one way?