Re: MLM Reed Adapter Thoughts?

I sprayed the reed intake seal with seafoam multiple times and didn't detect any leaks.

I'll take it apart and put it back again tomorrow and tighten / spray it again to double check. Could it be because I had to stack multiple reed intake gaskets together to get the screws on the back of the reeds to clear the intake? Might dremel them down a tad and retry.

Re: MLM Reed Adapter Thoughts?

DrGeorgeTompson (Alan) /

I dunno about an air leak.. You kept downjetting and it was improving, yes?

If it was an air leak, letting less fuel in would make it worse.

I would still seal a gasket stack if you think it's leaking, at least on the gasket to gasket surfaces.

Re: MLM Reed Adapter Thoughts?

Like I said, I sprayed down the whole engine looking for air leaks and couldn't find any, so I'd be surprised if that was the case.

I don't know if improving is a good way to describe it. Only improvement I saw was when I went from the W7 needle to the richest setting on the W9 needle. That made my revs feel really crisp up until the point where the main jet kicked in, and after that it would bog and die no matter what. For some reason, the 71 jet and above would make it bog rich (pulling the choke did nothing) and the 69 jet made it bog lean (pulling the choke gave it some life). I don't have a 70 jet so I wasn't able to try it out. But again, like I said- it currently has a 4 stroke atomizer / bushing, so that might be the cause of some of my problems.

Re: MLM Reed Adapter Thoughts?

It's a cast cyl?

Did you hone it? Often you will develop a glaze

On the cyl wall that must be removed when putting in new rings.

Just sanding the bore in a cross hatch pattern can work to break the glaze tho so the new rings can seat

What's the compression?

Re: MLM Reed Adapter Thoughts?

Am I correct in assuming that if a W7 at it's leanest felt too rich and the W9 felt best at it's richest (very bottom clip), then the needle I should try next is a W4? It has the same taper as a W9 but it's slightly thinner according to the chart on the wiki, so it should be slightly richer than a W9.

Re: MLM Reed Adapter Thoughts?

And, consider raising your float level.

If it's too low, the engine will fuel starve once it starts pulling hard

Re: MLM Reed Adapter Thoughts?

Yep it's plated inside. I didn't hone it but I broke the glaze as others have suggested by scrubbing the inside with wd 40 and scotchbrite. Not sure what the compression is but I tried the finger over the spark plug hole while pedaling with clutch activated trick and it pulled decently. I assume the compression isn't terrible if it starts (I'll admit it takes a lot of kicks to get it going though) and is capable of going 20-25 mph at 1/4-1/2 throttle. Should I get a lighter 2 stroke float too? Mine's a 4.5 gram float right now. I'll check to see if the float is sitting a little bit low tomorrow.

Re: MLM Reed Adapter Thoughts?

My very Reed ported 50cc Av7 with a stock bore runs a 95 jet in a 19 phbg with an airbox.

Without an airbox it would need to be in the 100s. (edited)

Re: MLM Reed Adapter Thoughts?

I think the MLM reed adapter intake is limited to something like a 16 mm inner diameter. Either way, I hope I haven't damaged anything by continuously running it lean / rich today. I guess I'll order the 2 stroke atomizer / bushing, a richer needle, and some more idle jets because my idle is still incredibly rich. When it arrives I'll tighten down the reeds / double check for any leaks again, replace the parts in the carb and check the float bowl, then start the tuning process all over again.


Oh by the way, I had a few questions for you Jbot on reed porting if you don't mind. What do you do if the cylinder you're porting had no boost ports to begin with? Do you just add your own and cut a boost window in the piston? How do you deal with plated cylinders after doing so, wouldn't the nikasil chip around the new ports and catch on the rings?

I'm asking because I was thinking of also eventually porting my treats 50cc cylinder as further porting practice a few months down the line when this current cylinder eventually goes, but I don't even know if it's worth it. No boost ports, but the piston does have a boost window. Would there even be a noticeable difference if the only change was a window cut into the piston for added fuel delivery, or does most of the impact from reed porting come from the 3rd transfer made from the boost ports actually allowing that extra fuel to reach the top of the cylinder? (edited)

Re: MLM Reed Adapter Thoughts?

You cut your own.

No, it won't chip if you do it right.

Chamfering everything is important.

Nothing sharp to snag a ring.

I sand every sharp edge til it's buttery.

Re: MLM Reed Adapter Thoughts?

Ah, makes sense, thanks. Wouldn't the addition of boost ports impact timing though? How do you go about the decision of where and what size to make said ports? Do you just match them up to the boost window on the piston and stop at the height of the transfers?

Once I get this reed port running, I'll do some more research and reading and might start porting my 50cc cylinder since it's not being used anyways. Then I'll have something to switch to and experiment with right away once I'm ready to switch cylinders.

Re: MLM Reed Adapter Thoughts?

It's only your boost port timing it effects.

Look up boost port timing.

I usually like to have them all at about the same height as the transfers,

But others do a staggered port timing with boosts opening at different than mrs than the transfers. I ride variated bikes tho and love that crazy strong hit that it makes when they all come on at once.

Your "intake timing" is now 360 degrees.

It's available constantly and you depend on the reeds to close the intake

which they do automatically.

Re: MLM Reed Adapter Thoughts?

I added ports high up on the piston to draw the majority of the fresh charge into the piston and across the wrist pin, it doesn't make as much power as a straight dump into the cases, but it keeps the piston cool.

You're way too lean, your bike has no power because it's running out of fuel. Go up to a 90s range jet, and keep the 4 stroke atomizer. W7 needle should be fine. Your porting is probably fine.

Also, which pipe are you running?

Re: MLM Reed Adapter Thoughts?

Currently running a proma circuit, I love the low-mid end pull it gives me. If I really did mess up on my diagnosis and it was running lean this whole time, I hope I didn't damage anything in the cylinder by constantly killing it by holding the throttle open until it dies of leanness.

I'll try something in the 90s when some 90s jets arrive. I think I'm switching to the 2 stroke atomizer / bushing anyways, I've done some reading and most people seem to agree that it's easier to tune in / run the 2 stroke parts rather than the 4 stroke ones.

Re: MLM Reed Adapter Thoughts?

Alright, my 90s jets arrived today. You guys were totally right, I put in a 98 and now it doesn't die when I floor it. It's still pretty lean and starved for fuel at WOT (starts accelerating and then lurches occasionally when it starts leaning out) so I'm going to order 100-120 and try those out. My copy of 2 Stroke Tuner's Handbook also arrived in the mail today, so I can't wait to crack that open and reed up on the subject before I port out my 50cc the right way.

Re: MLM Reed Adapter Thoughts?

Okay, I'm a believer in reeds and porting now. Need to tune it a bit more throughout the whole range but it hit 50 mph faster than the same setup without reeds would hit 30, even with the gearing being set up higher and the clutch not tuned to the reeds.

I've more or less read through most of the 2 Stroke Tuner's Handbook, so in a few weeks I'll probably take my other cylinder, port it out knowing what I know now, and case match (hadn't done that before.)

Re: MLM Reed Adapter Thoughts?

Reeding and making the intake available 360deg is the way to make big power easily. Lots of little things help. Piston Windows, boost ports, etc

Re: MLM Reed Adapter Thoughts?

Would there be gains to put the reeds right on the cylinder instead of the adapter and then an intake? Does the intake length not matter with reeds?

Re: MLM Reed Adapter Thoughts?

On a polini it would be very dufficult to do, unless you are a brazing master.

Re: MLM Reed Adapter Thoughts?

By the way, JBOT, meant to ask you this after I finished reading the book- when it comes to cutting your own boost ports into a cylinder that has none, how do you decide on width / depth / angle? The 2 Stroke Tuner's Handbook had little to say on the subject, the guy did mention that boost ports connected to the intake helped a lot on 2 stroke engines but followed up by saying that he didn't explicitly know the relation between the boost port shape / size and performance, and that it varied wildly between different widths. How do you decide what size to use? Do you just start small and work your way up? Match it to the boost window on the piston?

Re: MLM Reed Adapter Thoughts?

In my experience,

Boosts height at below the transfers gives a wider band,

Boosts at or slightly above the transfers gives a harder hit but a more narrow band.

This is just from looking at factory porting on dual variated kits vs e50 style kits.

As far as shape, just think flow.

You want the boosts to point up at the plug.

But besides that, your creativity is the only limit, and attempting to keep the ring gap protected if possible.

But.... I'm running a ring gap over some finger boost ports and nothing shitty has happened yet.

Re: MLM Reed Adapter Thoughts?

Interesting, looks like I'll have to play around with it. The boost ports on my current cylinder have the ports at about the halfway point on the transfer. I'll try doing it at transfer height for that hit so I can see the difference.

And yeah, I'm kind of worried about snagging a ring too haha but if you say you haven't had much trouble with it yet I guess I'll just chamfer/smoothen my edges out and stop fretting about it.

Thanks though, when I do get around to doing it I'll post again if I have any questions.

Re: MLM Reed Adapter Thoughts?

Just glad others are actively using this shit.

Knowledge is awesome.

Re: MLM Reed Adapter Thoughts?

Im talking about over all length... Woth the adaoter and then the reeds an intake it seems long... Does that not matter with reeds??? Im teying to wrao my head around all of tgis for when i get ballsy

Re: MLM Reed Adapter Thoughts?

I got a chance to fuck with this unit.

Few thoughts.

Very cool.

Works great with a reed ported pp cyl..., but attached reed block and bolt on intake needed work.

I had to thin the stupid not needed bridge on the Reed block and feather the edge of the intake to help flow. That Reed block is so shitty cuz they skimped on the cf reed. Too small at the edges so it can get sucked into the block. They put the bridge in to stop that but with a slightly larger Reed it wouldn't even need the bridge.

Reed ported a55 really kicks ass, beautiful idle, lots of low end.

I'd like to see these stocked again


Re: MLM Reed Adapter Thoughts?

I finally bolted one of these onto a Maxi project I'm working on. It had a generic PP 70cc kit on it and I had a windowed treats reed kit piston lying around that I threw in to take advantage of the reed valves. I used the reed adapter, boyesen dual stage reeds with slightly modded block for flow.

Definitely feels gruntier in the lows and mids than it did with the PP intake. Still dialing in the jet tuning.

One annoying thing is the carb placement for the bing. it's a super tight fit on a maxi frame, I had to remove the side rail to even get the fuel line to fit onto the banjo inlet. Figure this was probably originally designed on a tube frame?

Re: MLM Reed Adapter Thoughts?

Oh yeah special thanks to Todd for supplying the windowed piston :)

Re: MLM Reed Adapter Thoughts?

Here's my take at it. It ripped upstairs, but I dont think I'm getting enough scavenging at low RPM with these massive transfers and no boost ports - getting some serious low rpm bog. Going to be adding some finger ports and and a shooter from the intake here soon.

178 exhaust, 130 trans, 360 intake

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