Jetting Help 1975 RD350

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BobTrek
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Joined: Mon Feb 26, 2018 8:21 pm

Jetting Help 1975 RD350

#1 Post by BobTrek » Tue Feb 27, 2018 12:54 am

Hello guys, new on here, first post. I got this RD350 with DG pipes and the previous owner put the pipes on it and went from 130 to 150 mains. I bought the bike and first thing I did was pull the stock air box and install K&N generic air filters. I don't really know if it was jetted right for the pipes, but am certain if it was right, then now it needs bigger yet. What are your recommendations for mains, needle and pilots? Thanks in advance. I am at sea level in Tacoma, WA.

Bob

hondaror
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Re: Jetting Help 1975 RD350

#2 Post by hondaror » Tue Feb 27, 2018 1:07 am

K&Ns or knock offs? It matters.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

BobTrek
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Re: Jetting Help 1975 RD350

#3 Post by BobTrek » Tue Feb 27, 2018 2:35 am

Knock offs. I am surprised that matters

BobTrek
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Re: Jetting Help 1975 RD350

#4 Post by BobTrek » Tue Feb 27, 2018 8:12 pm

Can nobody help me?

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Evans Ward
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Re: Jetting Help 1975 RD350

#5 Post by Evans Ward » Tue Feb 27, 2018 8:39 pm

2 Stroke World may be your best bet as lots of AC Yam twins there.
84 RZ350-Toomeys,SCR milled head, stk 26 carbs,300 M, 35 P, stock regrooved needles AS 2.5 turns out,stk air box,Banshee reeds Zeel non-progr CDI,TSRL Program YPVS,alum rad,R6 shock,GV emulators w/RT springs,fork brace,Shindy steering damper.

hondaror
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Location: Alberta, Canada

Re: Jetting Help 1975 RD350

#6 Post by hondaror » Wed Feb 28, 2018 12:51 am

Throw the knock offs out, and buy K&Ns. We've run both on the dyno. Knock offs are more restrictive then the stock air box. The K&Ns will breath and you will have to go much richer than stock jetting. For example, if stock jets are 220, you will need to start at about 320, and you may have to go richer. You might want to pay for dyno time. It's much easier.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

Palolo
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Re: Jetting Help 1975 RD350

#7 Post by Palolo » Wed Feb 28, 2018 6:21 pm

Take a look here: https://hvccycle.net/carburetor-jetting/" onclick="window.open(this.href);return false;

And here: http://www.2strokeworld.com/forum/index ... 2#msg48282" onclick="window.open(this.href);return false;

If you're not using a Y-boot, UNI filters work great. Even better, use a silicone hose to create an intake runner between the carb and the filter. Think of the rubber tubes that go in between the stock airbox and the carbs.

Here's a pic of intake runners on my H2. Definitely helps low end performance.
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intake runner.jpg
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