SE50 swap on spree top out at 35

[Weezerjerry]

Hi all I swapped in a 93 Elite motor and it's great. My issue is I am topping out at 35 but am only at 1/2 throttle at best... I am using a polini 19mm carp with the smallest pilot jet I have and an 80 main jet. When I give it full throttle it almost sounds a little hollow and feels weaker than when around half throttle. My temp gauge broke but the hottest it got was 250 on a 90┬░ day. I just ordered a set of smaller mains from SSS to see if that will help at all.

Is 35mph what I should expect with an SE50 and 19mm polini carb? I am hoping for 40-45... I know, I know, if you've read my other post 35-40 was all I wanted... Bigger better faster

[noiseguy]

If you made zero changes to the drive side (variator, gears) or porting, why would you expect higher speeds? The engine isn't going to rotate any faster.

35 sounds like solid stock SE50 performance. Variator shell change is best bang for buck on that engine; $40 last I checked years ago. That and stock carb will get you 40 MPH.

What you describe sounds like lean bog but I'll let others more acquainted with this swap chime in.

[Meloshameless]

I had the same carb with a pod filter on my afo5, my jetting was 102-104 for the main. But there was other variables, i also naraku intake and bbk. Use ur air filter to test it. Heavily soak it in 2t oil causing a richer condition see if that helps wot. Or do opposite and run with out filter to see if it likes leaner. My guess is jetting is lean. Or warm it up, then pop in a brand new plug and do a short wot run and check the plug, ur playing with fire if its to lean though...

[Weezerjerry]

I guess I was just expecting a little closer to 40 after reading meatball's posts on here and with my Polini CP carb. I will do a WOT run and check my plug and maybe jet up a bit. I have up to a 98. What would you guys recommend jetting be on a stock SE50 with a Polini 19mm? Also one thing to note is I noticed my exhaust has 3-4 small holes drilled in the bottom of it. Would that cause a problem, or is that OK? It makes it pretty noisy but I'm honestly OK with the sound.

[Wheelman-111]

Greetings:

May I suggest your first investment should be a new Temp Gauge? Then you won't be playing with fire if your jetting turns out to be too lean. I'm pretty sure drilling holes in the stock exhaust isn't causing a top speed issue, but random mods like that seldom do much to improve performance either. Consider a LeoVince, Wild Lion, or G9's Slick Willie if you can get your hands on one. I agree that 40 or better is totally reachable with the setup you have. Tuning makes the difference; lots of Trial & Error, but it's all Fun.

[Weezerjerry]

Thanks Wheelman! New temp gauge is on order! I am planning on using my laser temp 'gun' tonight to see how some jetting helps or hinders... I was thinking 40 with that carb might be possible. I am wondering if anyone else out there has any experience jetting an SE50 with a Polini carb? Doesn't the stock carb run an 80? I hear the Polini's are gas sippers and usually run lower jetting than expected so I was thinking maybe I'm too rich... What are good stock temps for this engine?

[noiseguy]

I remember when I started the board Maddog used to abusively rant at people that would try to make scooters faster through the motor without addressing drive face / parts.

[Weezerjerry]

I definitely need to upgrade the vari and maybe look for some gears. There's good power, I'd just like to be closer to 40 then the 33-35 range. I'm also wondering if the back tire size might be an issue, it came with a 2.5 I'm thinking a 3.0 might be a little bigger and help with speed? Thoughts?

[Meloshameless]

Ive had 2 unrestricted se50's both did 40 stock. Very attainable. That carb should give u good mid and low end gains. At least it did for mine, but i also did intake at the same time. U running stock intake? And yea 3.0x10 is stock tire for that. Should give u 1-3 mph gain if u swap out that 2.5..

[Weezerjerry]

I am running the Polini pod filter. I was told to not oil that filter, is this correct? I will swap out the tire this week hopefully.

[Meatball]

Im running the stock carb so this may not apply but when I swapped the gears from an unrestricted SE50 to mine, I only gained about 1mph. All the gears are the same except for gear "A" on this chart (link below) which has one extra tooth. It changes the ratio from 11.097 to 10.244. I didn't notice a difference in acceleration OR top-speed so in my opinion the gear swap is just not worth it. However, if you did a bbk and swapped gears to like 7:1 then that'd net crazy top speeds. Im keeping stock bore to keep the cops off my back so my quest for better performance are going to be strictly variator/belt/roller/clutch spring type mods.

http://hondaspree.net/wiki/index.php5?t ... ion_Ratios

My tires are 2.5x10 and Im seeing 40mph on flat all day. Theres an amazingly long and steep hill near where I live and my GPS hit 54.4mph the other day when I bombed it.

[Weezerjerry]

That's crazy meatball! I hope you have some good brakes!!!! Thanks for the feedback! Also thanks for the PM with some tuning advice!

[Weezerjerry]

Maybe I should slap on the stock carb and airbox to see how she goes and listen to it to see how it should sound as well... Duh! Though it will sound a lot different with that airbox.

[Meatball]

Id say try it. Do a few speed runs and test it out.

[Weezerjerry]

Only issue, I just remembered I will have to dig out a throttle cable as I am using a different cable for my Polini carb.... We shall see what I get done tonight.