More torque out of 85' Spree

[Rancher1]

The reeds appear to open ok. I gave a weak try to remove the reed valve but it's caked on there pretty good. I stopped because I figured I'd rip the gaskets and/or crack the reed valve. Maybe I'll buy another valve and some gasket material then give it some muscle.

So here's another interesting observation.. It tends to smoke a bit more than I thought normal so I pulled the oil line, plugged the now open manifold oil port and see that it still smokes. The bore is new so I know there isn't any residual oil cooking out there. I pulled the spark plug and it's dark/oily. The fuel is fresh with a small amount of stabil and a tiny amount of seafoam. The only thing I can think of where oil could be coming in is the oil pump gasket. Do these go bad easily? I didn't bother to pull the oil pump since it works fine and figured no one else opened it up. A bad seal there could also explain the low compression. Thoughts?

[Rancher1]

I'm not trusting my compression tester. I ran it on my other bike and it gives a similar low reading. That's what I get for buying cheap tools I suppose.

I figured out what was going on with the smoke, air mixture way backed out, and unclean response. It's so simple I'm a little embarrassed. The main jet is just too big. Stock is #68 and the one included with BBK is #87 (off brand). I put the #68 back in and the throttle response is crisp (though a little weak) without the big smoke dump. It fades out at WOT with classic too lean condition. So, the right jetting is somewhere in between #68 and #87. I still got my european jet kit on order so I'll wait for that to arrive and report back what I find works best. From what I hear, it could be awhile before it arrives.

[Rancher1]

I left the oil pump in and it appears to pump/function correctly. Additionally, I premix about 50:1 as well. From what I'm told that should put the final ratio somewhere between 30:1 to 40:1. I haven't measured the actual pump output myself.

[Rancher1]

Alright, finally got her jetting dialed in. #84 main, needle clip in leanest position, with 2-1/4 turns out air mix. What I was finding is the main jet was heavily influencing the initial throttle response, much more than I've seen before. So the challenge was leaning out the pilot circuit as much as possible with a jet just large enough to provide good response without running dangerously lean on the top end. A bit frustrating to tune but I think it's pretty decent now. Overall power of this Tai bore is good but not much to write home about.

Maybe there's something else going on with it but I'm content with where it's at.

[AT978]

Hey guys, I'm new here and also new to my spree.have a few questions, adjusting the idle can be done with both the screws on the carb. How do I adjust it properly? I have a terrible low end and it takes until about 15mph before torque is normal. I've got a couple friends that have 87s and both of them have better acceleration. However, I can go faster than them both downhil, any idea why? I'm not heavier than they are. Also, they have a top speed of about 35 while mine in topping at 28 on a flat surface, manage 37 on slight decline. Thanks!

[patthesoundguy]

84/85 sprees top out at 28mph that's just how it is. The gearing is slightly different on the 86/87 compared to the 84/85. The manual has the procedure to set the idle air mixture and idle. You do them both together. It's fairly easy to do but if you are using a big bore kit you may end up having to run the mixture screw almost all the way in to get it rich enough. If the idle air mixture is too lean you will have no real off the line acceleration.

[AT978]

Is there any way to increase the top speed by about 5 just doing simple modifications? How easy is it to switch a belt? I can't find the how-to for it

[patthesoundguy]

You can do the belt swap, its tricky but good for 5mph pretty much. The big bore kit makes the belt swap work, you will loose some low end take off but with a big bore kit it won't. Be all that bad. There is also the pulley mod which is in the Wki I think. The danger with the belt swap is getting it installed with out jamming the belt in the drive pulley and getting the pulley crooked and stripping the end of the crank shaft. I ran my spree with the big bore kit, 21mm carb and intake with the MLM pipe with the belt swap and it flew! 40mph was not an issue. No one has really been successful with the belt swap as we had the wrong belt size and the belt was a shade too long. I have done the swap with the belt that works but its a royal pain. Once it's on there its fine. That's another tutorial I need to do

[deuce217]

Put a pipe on there from a polini x5 dirtbike (tuned 50cc pipe) you will need to weld that on the down pipe/ header from the stock one. Put in the gears from Tazland001/ chopchop123 on ebay and 21mm carb, ct intake, BBK and you can reach 45mph all day long. No head gaske (just use copper gasket spray), and shave the head down until your compression is about 150psi (this requires a lathe or milling machine for best results.

[AT978]

Yes! I need a tutorial for the belt swap!! And every single detail, part list, ect

[patthesoundguy]

You need all of the tools to get the whole thing apart +belt and a small wood wedge. The small wood wedge is to hold the driven pulley apart fully to have enough slack to install the drive pulley with getting the belt jammed a causing the crank threads to get stripped. I'll get a tutorial together as soon as I have the time.

[AT978]

Awesome, please post a link on here when you get it together! Thankss