stock carbs

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hotshoe93
Posts: 55
Joined: Fri Nov 16, 2018 8:57 am
Location: Columbus Ohio

stock carbs

#1 Post by hotshoe93 » Fri Nov 30, 2018 4:08 pm

What pilot jet should i have in the bike (20?) , stock carb toomey pipes and air box.. I'm cleaning the carbs and the book lists a 85 air jet , can't seem to find a pic or location for it in the manual or parts book ? is it in the throat area ? Thx
84 RZ350 Toomey
2003 FZ1 Yellow/Black
BULTACO ASTRO
Champion framed Kawasaki F81m
BULTACO SHERP-S Brakeless Dirt tracker
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brrrappp
Posts: 603
Joined: Tue Sep 18, 2018 10:21 pm
Location: USA

Re: stock carbs

#2 Post by brrrappp » Fri Nov 30, 2018 4:51 pm

For stock carbs/lightly modified or stock porting, there are really only 4 things to play with unless you are willing to spend a ton of time and effort.
:
2 jets Main Jet and pilot jet
Most everyone uses the stock #20 pilot.
The mains are an open discussion. Stock was a 230.
Jet NEEDLE (NLA OEM) Kit parts available from various sources.
Air Screw (NLA OEM) economy cycle has replacements

The Toomey "KIT" came with pipes, jetting and a single large airfilter attached by Y-Pipe. This eliminated the airbox.

The Jet kit consists of different needles, 410 and 420 mains.
Both my 84 and 85 run great with the Toomey/Dyno-Jet stage 3 jetting spec KIT NEEDLES and 420 mains but you will find people all over the place on jetting here on this board and elsewhere.

If you are a high-level tinkerer there are parts catalogs and spec sheets for you to mix and match needle jets and jet needles as well.
RZ350L-N-NC Manual 126.jpg
RZ350L-N-NC Manual 126.jpg (101.84 KiB) Viewed 752 times
Last edited by brrrappp on Fri Nov 30, 2018 5:16 pm, edited 2 times in total.

brrrappp
Posts: 603
Joined: Tue Sep 18, 2018 10:21 pm
Location: USA

Re: stock carbs

#3 Post by brrrappp » Fri Nov 30, 2018 5:02 pm

https://websites.godaddy.com/blob/d08aa ... f?ca314f21

Above link to Toomey instructions including Jet install

https://www.ebay.com/itm/Dynojet-Carbur ... :rk:2:pf:0

Above link to a seller of DynoJet kit for RZ350 with pipes $50

hotshoe93
Posts: 55
Joined: Fri Nov 16, 2018 8:57 am
Location: Columbus Ohio

Re: stock carbs

#4 Post by hotshoe93 » Fri Nov 30, 2018 5:14 pm

Thanks a ton for your response. cleaning carbs in a agitater . I think I want to change the pilots just for kicks.i thought they were 20. I have 410 mains, not sure what else was done to the carbs but my bike came with some extra jets and info from dyna jet, so I assume this was the mod done to the carbs. I think the air screw plug was drilled and removed so you can have access to the air screw?? We’re the air screw fixed on the stock carbs? Where best place to get rebuild kit, really will just need float gaskets, prob the fuel valve assy with o ring.
84 RZ350 Toomey
2003 FZ1 Yellow/Black
BULTACO ASTRO
Champion framed Kawasaki F81m
BULTACO SHERP-S Brakeless Dirt tracker
ZUK A-100 w/ FACTORY HOP UP
:smt026

brrrappp
Posts: 603
Joined: Tue Sep 18, 2018 10:21 pm
Location: USA

Re: stock carbs

#5 Post by brrrappp » Fri Nov 30, 2018 5:31 pm

Yes - USA models were purposely restricted for the EPA.
You carefully drill the caps and then you can adjust the airscrews. 1.5 turns is baseline.
I would stick with the #20 pilot and 410 or 420 main until you can actually ride it and see how the bike responds. All engines have slightly different fueling requirements. Temp, altitude, engine condition, air filter condition, fuel quality, alcohol content etc all come into play. The 420 is for sea-level at kind of "normal" temps. 410 was a high temp or high altitude alternate. The jetting is a little "safe" and you can adjust leaner to some degree but it make zero sense to play with jetting before you actually test drive the bike at length and identify any rich/lean condition.
It's probably more important to be certain that the slides open evenly and float height is correct.
Most riders will see a bigger difference in the NEEDLE CLIP position change than from a +/- pilot jet change.

brrrappp
Posts: 603
Joined: Tue Sep 18, 2018 10:21 pm
Location: USA

Re: stock carbs

#6 Post by brrrappp » Fri Nov 30, 2018 5:34 pm

Needle and seat is available from YAMAHA OEM. As is the bowl and top gaskets. There are seals where the linkage arm that lifts the slides enters the top-side of the carb that are also available. I've been waiting for mine to show up from backorder.

brrrappp
Posts: 603
Joined: Tue Sep 18, 2018 10:21 pm
Location: USA

Re: stock carbs

#7 Post by brrrappp » Fri Nov 30, 2018 5:48 pm

The Fuel Petcock repair kit for the USA RZ350 is available on Amazon. K&L Supply Fuel Petcock Repair Kit 18-2730.
This kit has the diaphram, the o-ring for the on/off and the little rubber part with holes in it behind the fuel valve.
The O-Ring for the petcock bowl does NOT come in the kit and is available from Yamaha.
The long oval o-rinr between the petcock and the tank is available from Yamaha.
The special screws and thick paper gaskets that hold the petcock to the tank are also available from Yamaha.
The entire petcock is still available for about $140. As is the Black switch/knob

brrrappp
Posts: 603
Joined: Tue Sep 18, 2018 10:21 pm
Location: USA

Re: stock carbs

#8 Post by brrrappp » Fri Nov 30, 2018 6:11 pm

Other advice:
1: There is a holding plate that attaches to the left carb with two screws. Your throttle cables are held in position by this plate. One of those screws is extremely hard to get to unless you separate the carbs. You can do it without separating the carbs by rotating and sliding the parts. Make sure the screws are tight! The most difficult to get at (top one) is known to loosen up.
2: Look at your throttle cable. The round plastic junction where the oil injection cable and the carb/throttle cable join rubs against the frame and wears through. This allows dirt and grime into the cable junction causing a sticky throttle. I cut a short length of small diameter radiator hose and wrapped it around mine to stop any future chaffing. You can use similar diameter general purpose hose or emissions hose sourced from a auto/boat or hardware store.
3: always verify your oil injection pump settings after you reinstall your carbs and adjust the cable free-play. Every time you adjust the free play on the throttle cable it will change the oil cable throw as well.

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