VM18 carb mount too wide for intake.

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Apr 9, 2018
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#1
I'm having more problems with my build. Where the Mikuni VM18 clamps it is much wider than my RSE reed valve intake. Could I get a thicker plastic shim and use that or do I have to get one of those case reed valves with the wider pipe mount. I'd prefer just getting the shim since I already have alot of money into this.
 


FurryOnTheInside

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#2
I am no expert but it is my understanding from the previous forum threads that the RSE reed valve was not designed to be used with an 18mm Mikuni carb..
The RSE reed valve has only a small area even when fully open which many have reported actually restricts the intake flow at high rpm, and a reed valve engine's increased intake duration means that, rather than a quick gasp like a P.P. engine, it takes a longer inhale more slowly so it really doesn't need or want a large diameter carb that would further slow air velocity over the venturi.
In short, the RSE reed valve renders the 18mm carb redundant.
I believe you might find that the stock carb's diameter is more appropriate for the RSE reed valve; or that a P. P. intake or perhaps the four petal OZ reed valve is better suited to your 18mm Mikuni carb.
 
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FNTPuck

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#3
I haven't actually ran either yet but have both sitting here and if you are running a larger carb I would lean towards the proper case reed valve setups over trying to adapt the RSE setup.

The RSE reed valve is a very tiny, restrictive looking piece. It matches up to the stock NT carb, but not the larger ones. With the higher end kits that come with the larger clone carbs like the Keihin, they get a proper sized reed valve in a boxed intake to house it like on a dirt bike. After seeing both side by side, I have a hard time convincing myself to run the RSE valve that looks like a huge restriction vs the full size one. Here are both styles next to each other(click for full size):
RSEvsCased1.jpg RSEvsCased2.jpg RSEvsCased3.jpg
 

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#4
Well I noticed that the bigger reed valves come with a carb already. I don't want to get a reed valve with crappy petals. If I can't get my money back for the rse I'll use it on the other engine. I also need an air filter for the mikuni. The 1/4 aluminum for the spacer still hasn't come in yet.
 

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#5
Does anyone know any reed valve intakes that a VM18 will fit on? I'm looking for just the reed valve because I have the carb. The ID of the clamp part is 23mm. I just can't find the right thing to use, I see the ZEDA OZ reed valve is sold out on one site and on another it's the wrong size manifold. I also found it for sale as a bundle with a cylinder, piston and other stuff but I want just the reed valve. All the rest are either similar to the one I have now or won't work hmm.
 
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Spare_Parts

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#6
Jlzeda on Amazon has the OZ reed with 19 and 21mm carb adapters. Can't find the reed valve with 3 adapters right now but if I stumble on it I'll post a link.
 


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#8
One guy said it did not come with it. I honestly don't know with the stuff I've heard about Zeda's stuff. Would I have to ask for the 23mm manifold to get it or what?
 

Spare_Parts

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#9
It's not Zeda motor sports, it's JLZEDA. Search JLZEDA OZ reed on Amazon and it will show up. They are sending out the 23mm adapter by request. I would message them first to make sure. I have bought from them and never had an issue.
 



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#12
im running the OZ Reed from JL on Amazon right now and even tho i purchased it before they started having the 3 sizes of intakes for it i was missing the to with but it got sent to me like 2 weeks later and its been running strong ever since but im not running case reed im running a ZL short crank bottom end with a max ported zeda80 cylinder OZ reed and mz65 pipe. and honestly i havent gotten this bottom end outta breakin yet but even not quite tuned right and exhaust gasket issues from to much bounce in the pipe from rough side walks it wants to cruise at 40mph almost it seems at barely 3800 rpms so im hoping thats good lol
 

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#13
I ordered it and the 23mm got a uni air filter and threaded rod to make longer studs. The cylinder I'm using is a big bore 48mm iron sleeved. I'm wondering if it will be able to go 40 too. I'll be using a NGK plug (the thing is idk if I should have got the longer plug since I got a B5HS), one of the banana pipes, VM18 and the reed valve. I was thinking of getting the OZ magneto too and a stage I CDI. Already put alot of money into it though so probably stick to stock. I want to build a road legal bike soon maybe with a small 4 stroke honda or other japanese engine. The only problem is how to make a charging system work since in my states to make one legal you NEED lights if you want a moped registration. I was thinking GXH50 but those are pretty expensive and I'd have to mess with the governor and carb atleast that's what terry blow said in a video I would still want the Honda over the Huasheng though.
 

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#14
i got same air filter and plan on chopping some bolts when i get free time for studs to jb weld in place i think that will fix my exhaust issue i hope i use stock cdi with plug wire from ace hardware and b6hs plugs with a super magneto from CR machine not to mention ive upgraded to sealed bearings all the way around and have an origin8 Hornet freewheels on it lol its loud af
 

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#15
Sealed main bearings? shouldn't they be open so the 2 stroke oil can lubricate? I guess it might be better because any shavings from break in can't get to the ball bearings. I have brand new Japanese bearings in the black crankcase and the other crank is stuck on the bearing. I could have used those but am just going to go with the stock ones in new block. It was a pain even taking apart the other one.
 



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