Honda Spree and Elite 50 Forums

Hey guys, I just finished up restoring an '85 Spree. All stock and runs like a champ.

I'll be installing an SB50 intake and reed block, Polini 0.25mm carbon reeds, SA50 17mm carb and a custom pipe (hacked up Doppler pipe from a Derbi GPR application converted to side bleed, adjustable end bleed and using part of an OEM header to mate to the cylinder). Obviously all at the same time to avoid retuning a whole bunch of times.

My question is where i should start on jetting. Looking for a ball park kinda answer to avoid starting waaaaay off, placing several orders and having a ton of useless jets.

Here's a pic of it just for fun. (OEM replica stickers in black have since been added)

With that kind of setup, you should be able to bump up to a 70. 68 for sure. I'd stay in the range of 68-76 if your looking to experiment. Higher then that, you start dwelling into BBK jetting turf. Let us know the results with that pipe, you should be getting, I'm guessing, somewhere around 34-35 With what you have proposed.

Beautiful Spree there, Cam. Love the rear tail light assembly.

Awesome, Thanks for the quick reply! I'll definitely be updating with findings. No plans for a big bore in the near future but yea, this should leave plenty of headroom. It does have a ton of mileage though (10,500km) but compression is ok (105 psi cold) so i'll wait till its either tired or seized. The stock (14mm?) carb currently has a 68 in it. From what I've read the SA50 carb should come with a 78? I don't have my hands on it yet.

Thanks! Here's a slightly better angle of it. It's just one inch angle aluminum bolted in place using the license plate mount, the indicators slot on perfectly after making a small slit to pass the wire. I didn't even have to extend the factory wiring!

It's the original factory finish. Canadian market only apparently. It was in pretty rough shape when I picked it up but buffed out pretty well. Though it looks better in photos if I'm honest. I'll take a few more pics as soon I get a chance.

Little update...Still waiting on the intake, intake parts and carb but I managed to hack together a pipe for it.

I'm diggin' it!!

So I took .025 off the aluminum drive pulley, port matched the SB50 cage to it's intake, made a new reed using a .25 thick carbon sheet, converted an SA50 carb to manual choke and bolted it on (it actually fits, just barely).

The SB reed stop doesn't allow the reeds to open as far as the NQ reed stop. Has anyone tried using the NQ stop on the SB cage? I didn't bother since it's much large anyway but I might try it next time I'm in there.

Throttle response is greatly improved, bottom end is about the same as stock and it pulls well from about 20 kp/h. Fasted recorded speed was 62 kp/h using a phone based speedo app. This was with a 74 main jet. Seems kinda lean. The one that came with the carb was too large (just barely 4 stroking). No idea what size it is.

62kph ya say? Nice. Wouldn't happen to have a tach hooked up to know how many RPM your pushing would ya? I'm guessing close to 10k with that kind of speed.

Speed calculator says 10k rpm on an 85' Spree as well.



Would expect that pipe might be capable of more. After you get it dialed in, consider a BBK. It looks as if you are probably about ready for one. If ACTUAL rpm is too much higher, check the clutch pads, springs and belt out. The calculator is VERY accurate for the AF05 engine with a new clutch, belt and springs, since a Spree, is NOT CVT based. Higher RPM's at that same speed, will indicate slipping.

Numbers above are for the stock 85' gear ratio (12T), using 2.75x10" wheels.

I didn't have a tach hooked up but there's one in the mail for my moped. Maybe I'll hook it up to check rpm whenever it comes in. Tires are 2.75, i didn't calculate gear ratio after the pulley mod.

Cruising speeds are more like 55 give or take 3-4km depending on grade and wind direction. 62 is fully topped out on a long smooth road and ridiculous tucked in racer body position.

At what RPM should I start to worry about the crank getting all snappy? Haven't seen any aftermarket ones out there...or even oem come to think of it.

That I'm not sure of. Mine will do over 11k, I wanna (try and) push it up to 12, but I don't plan on doing that till I install the ported BBK. But anyways, you never mentioned you had done the pulley mod as well. Bet that's a slow takeoff!! Pulley mod is kind of a waste IMO, you only gain like 3-4mph/kph doing it and lose alot of bottom end. Although, it would be kind of fun to see how fast it goes with both the pulley mod and some Taz gears. My top speed on the dyno (not real world) is 52 (83km/h) and that's at a little over 11k. According to the calculations, I should be able to achieve 57 (91km/h) if I can hit 12k rpm. I would imagine one could get it past 60 (96km/h) with both pulley mod and gears, IF the crank holds out. I plan on attempting it with the full expectation of blowing the engine, but no biggy, I have a backup. After you get the tach, if you wanna shoot for 12k, go for it (if you dare) and report back. But I'd for sure, maybe run it a tad on the rich side for extra cooling... But anyways, it's hard to estimate final drive with the pulley mod, but if I had to guess, I'd say that dropped you down to maybe 8500-9k??? Should be good for 40 (65km/h) with that pipe, probably slow getting there, might need less wind, but I'll bet you can do it.

Man, yours sounds like a total beast. I feel like I've already maxed the speed potential of this one since it's lowered it an inch up front and 3/4 out back. I weigh 160 and its bottoming out at the speeds I'm seeing but i built it for my lady and she weighs considerably less so it should be fine for her.

Yep, mentioned it in the post before your calculations. Im thinking of taking even more off the pulley and then correcting back to stock or around there using shims. That way its tuneable. Though you're totally right, its not at all worth the drop in acceleration from a dead stop for such a small gain in top end. Plus it's top speed is power limited not gear limited like I thought it would be. Maybe changing the clutch springs to get a higher stall speed would be the best of both worlds?

I'm pretty sure the pipe design is limiting max rpm since i used the first few inches of the stock header and it starts expanding after very early. I figured as much bottom end as possible is the way to go with these things.

So i'll reduce the gearing and retest when I have a chance. Or maybe stiffer clutch springs. hmmm

Cam.V wrote: clutch springs to get a higher stall speed

Malossi 29 7454 spring kit can fit the Spree. Comes with 3 sets: 4k, 5k, 6k depending on where your scoot likes to revv with your pipe.