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Pilot jet parts, how do they go together?

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I had to dissasemble, clean and reassemble my DR350s carb,the gas had "conjealed"(?!)...now the bike won't idle unless I have the choke in the "on"(pulled out)position.

I'm thinking I did'nt reassemble the idle air mixture needle assembly parts in correct order.

I have a air screw needle,an O-ring, a Stainless Steel washer and a spring.

Anyone know what order they go into the carb?.

A admittingly noob like question, any help would be appreciated.

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In order of insertion, I believe it goes spring, o-ring, washer, needle.

I took the carb apart today and I have it; spring,washer,o-ring and then needle,...definitley different than your combination,...

The carb has got to be the cleanest carb out there by now,...

got to be the combination,...any other opinions before I reassemble?.

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What year? This sounds nothing like my 1993, so I'm just curious.

I just went through this... my bike had over 40,000 miles on it and had sat in a barn for 4-5 years. Pilot jet was clogged. Drove me nuts till I figured it out.

Actually, if you wind up in a bind on it, I ended up buying a low-mile used carb from Jesse Kientz at www.kientech.com Folks put on slide-needle carbs, and the original unit is worth nothing.

Figuring that with the miles I've got on mine, low-mile replacement parts wouldn't hurt. Worked like a charm, bike will turn 48,000 miles this coming weekend.

Best,

Doug Grosjean

Luckey, Ohio

douggrosjean@wcnet.org

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Me thinks I'll try the "other" combination before giving up on this carb, but thanks for the idea.

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I don't understand what you mean, I though the pilot jet just screwed into the carb body, nothing really underneath it...Would you mind looking at this picture...is it really part #31?

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Thanks for the input people.

Well thats one of the schmatics I found on the net, and yes #31 is the pilot jet, I think it's interesting that they are not listing/showing ANY of the related parts in that assembly(?!?).

Also, #35 and #36 are listed as air jets??, I can't seem to remove those for cleaning purposes and can't figure where they exit, ie., I blow them out but can't see/hear where they exit, maybe that's were my prob is?!.

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I don't know about blowing them out...but I don't believe I could remove them on mine either. The carb pic is just how I remember mine, I thought the pilot jet just went straight into the carb body w/ nothing else (unless I'm "temporarily" insane)...Maybe this link might help?

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Me thinks when you changed your idle air screw the "other" parts stayed in the carb,...the needle IS the last part "in".

On my carb it was part luck,part good observation to find/not lose those really tiny parts.

And there is the rub my friends,...the smallest parts on this bike have created the biggest problem I've had with it in 10+ years 😢

Cheers.

Jeff.

I don't know about blowing them out...but I don't believe I could remove them on mine either. The carb pic is just how I remember mine, I thought the pilot jet just went straight into the carb body w/ nothing else (unless I'm "temporarily" insane)...Maybe this link might help?

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I looked at three different online "fiche" diagrams untill I came across one that showed the extra "bits".

The setup on the fiche looks like: O-ring first,washer second, spring next and idle screw last.

Will try it tomorrow.

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I don't know about blowing them out...but I don't believe I could remove them on mine either. The carb pic is just how I remember mine, I thought the pilot jet just went straight into the carb body w/ nothing else

I think the little jets in the carb mouth are just air jets. I don't think they get clogged, as they don't flow fuel.

I couldn't get them out on the 41,000 mile carb, but they came right out on the low-mile used carb that Jesse sold me cheap.

I did blow out the passages (with carb cleaner and then air), but don't recall for sure where they came out. I think they're refered to in the factory manual as PAJ, or pilot air jets. I think they're used to lean out the idle mixture.

Couple things that drove me crazy:

Bought a #37.5 pilot jet from a m/c shop's assortment, and it was horribly rich. A #40 was better, but shouldn't have been. Finally ordered the #37.5 from Suzuki, installed it, and all was well. Though both were 37.5, the Suzuki one was a different design. The non-Suzuki had a bunch of bleed holes drilled into it, the Suzuki one did not. Made BIG difference, and not a good difference.

I mentioned it before, and will mention it again. If you do get in a bind, Jesse sold me a very nice low-mile carb and an adjustable pilot screw for $40 plus $6 shipping. For as cheap as that was, and considering how many times I'd had the carb on and off chasing little tiny gremlins, it was worth it to me.

One other thing - I used MPG figures to tell when I was getting it right. Commuting, my DR gets about 60 MPG. With the big pilot jet and JX needle and everything stock, it was around 40 MPG. As I got things cleaned up and closer to "right", MPG came up.

It ran really good rich, but stunk. And since I sometimes have a long commute (as much as 94 miles one way some days), I really wanted the good MPG.

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Well, it idles now, but only with the idle air mixture screw turned right in. ?

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sorry to be silly, but are you sure its right in? sometimes my screwdriver would bind against the side of the chamber making me think it was in or stopped when it wasn't?? Usually if you have to go all the way in then you need a smaller pilot jet, but since your problem developed afterwards then probably not......yeah, maybe try putting the screw out further (like 1.5-2-2.5) then readjusting the idle screw/setting to then recalibrate the pilot air screw........

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I appreciate your input,...I'll pull the carb again,(and damn I'm getting good at that!?), and double check the screw.

I recently opened the airbox and jacked my needle up to the bottom groove, I'm running the stock 135 Main jet/exhaust...it certainly runs way better off idle, seems more responsive etc..

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Well, it idles now, but only with the idle air mixture screw turned right in. ?

Sounds as though you have enough fuel coming in via the needle jet and needle (even at idle), that you don't need the pilot circuit.

I also bet that the engine is rich everywhere else, exhaust smells rich, and fuel mileage is poor?

Are you using the JX needle?

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Why would you need to open the carb to adjust the screw? Are we both talking about the one on the bottom of the carb body (outside?)pilot air screw...And you mean the clip position closest to the tapered end of the needle, not the blunt end right? that's where you have it? if so isn't that the leanest position?.........

I'm confused here, Gman says you probably should HAVE to go to a larger pilot jet when opening the airbox if you have any significant airflow increase...but you're saying that you have to put the pilot air screw in all the way, which means that you had to DECREASE the effect of the pilot jet via the pilot air screw...doesn't make sense....

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Thanks NBot,...I've got the needle all the way "up" in the main jet, the richest setting for that combo.

I was going to pull the carb and clean it again.

Will check out the idle air mixture screw as per your hint as well.

Running(idling) best with the idle air mixture screw all the way in makes no sense to me either,...

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Unless my mind is failing me I think most people put the clip on the fourth one "down" (second from the taper). Maybe that's affecting your idle? But I thought the needle wouldn't affect the idle as much being a different fuel delivery system for a different part of the band. Well, unless I'm crazy I'd put it on the fourth, blow compressed air once more, try your idle screw richer, and screw out the pilot air screw some. Also make sure that your diaphram doesn't have a hole/tear in it.

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