'74 RD350. Yeah... I know....

Jim

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While we're on the carbs....
Ordered some stuff from Niche Cycle. Half the parts didn't fit. Email from a guy there who has an old RD said that the new VM28's are all they have parts for... said the old VM28's are a fair bit different and they don't have parts for 'em. Anyone know of a source for bits for a 70's era VM28?
 

Jim

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Thankfully the choke lever is a direct swap. This old one soaked for weeks and is still locked solid and pitted almost all the way through in places. Didn't relish reusing it.



1669672765483.png
 

Jim

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Thanks JP. I shoulda thought of them.... :rolleyes:
You recall off the top of your head which style needle jet these 28's take? Mine are pretty mangled after I beat 'em out.
 

arcticXS

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Yeah, I'd be interested in reading that. In the back of my mind I recall we modded the carbs quiet a bit... but that was all 40-50 yrs ago. I've had a few tokes since then... :smoke:
Also, it is generally recommended to add 2 locating dowel pins, to ensure the head is centered over the cylinder. Especially important if you plan to tighten up the squish band. I believe both head mods/ dowel pinning, and the carb mods are covered in the Dale Alexander/ Dave Freist writeups.
 

jpdevol

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Thanks JP. I shoulda thought of them.... :rolleyes:
You recall off the top of your head which style needle jet these 28's take? Mine are pretty mangled after I beat 'em out.
My VM28's have the 169 series, IIRC P-0
 

Signal

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I have found Mikuni in Australia very good and have lots of info on the website.
https://mikunioz.com/?v=13b249c5dfa9

Hopefully attached is the PDF of the mod. I had a quick re read and they don't mention that you need to also cut the spray bar on the needle jet down to 2mm high. I read this in Dale Alexanders tuning guide also attached (hopefully)
 

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  • Dave_F_Warb mod-Pictures.pdf
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  • RD 350 tuning guide Dale alexander.pdf
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Jim

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I have found Mikuni in Australia very good and have lots of info on the website.
https://mikunioz.com/?v=13b249c5dfa9

Hopefully attached is the PDF of the mod. I had a quick re read and they don't mention that you need to also cut the spray bar on the needle jet down to 2mm high. I read this in Dale Alexanders tuning guide also attached (hopefully)
Thanks Signal!
thumbsup.gif
 

arcticXS

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Thanks JP. I shoulda thought of them.... :rolleyes:
You recall off the top of your head which style needle jet these 28's take? Mine are pretty mangled after I beat 'em out.
The stock RD350 needle jets are the emulsion/ bleed type. While the R5 needle jets, used in the Dale A mod is the primary type. I did those mods to my RD350A carbs, with good results.
 

MrBultaco

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Have you tried Sudco? They were the go-to in the 70's and I bought needle/seat and jets for my '82 Seca years ago.
 

Jim

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I did buy directly from them in about 2012 or so...no problem.
Just looked at their catalogue.... Says sales are only to licensed dealers with $500/yr minimum order to stay in good graces.



1669745874841.png
 

jpdevol

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Jim - do your VM28's have one choke, a choke tube and are the NJ's primary or bleed type? Also, are the carb tops regular or "high top"? I'm getting a suspicion that there were different VM28's around (don't know what's OEM and what's aftermarket genuine Mikuni)
 
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