85 Spree, test bed for mods

scootercouple · Post by **scootercouple** » Sat Aug 09, 2008 4:03 pm

Hoping to see what can be done for litte $! Just bought a matching Spree to yours for $200. Good little machine, but lags near the top end where my Suzuki FZ50 does a little better.

keithw · Post by **keithw** » Sat Aug 09, 2008 5:57 pm

I paid $225 for mine. A fair price I think concidering what it needs to get it sorted out. Won a stock muffler on ebay and the air cleaner element should be here any day. Once those are installed and the jetting verified I'll take the GPS and do some base line speed runs. Playing around with the Pal I plotted speed vs acceleration curves. This shows what the top speed is and where it pulls the hardest. I'll do about 10 runs and combine the numbers. This should provide a good average.

keithw

scootercouple · Post by **scootercouple** » Sun Aug 10, 2008 12:27 am

Is the GPS needed to run the Pal? Just wondering why the GPS rather than the speedo. Is the GPS really that accurate?

keithw · Post by **keithw** » Sun Aug 10, 2008 9:49 am

The GPS is quite accurate. The biggest reason that I use it is that it records your position and speed data. That way after I get home I can dowload the data. Once I have the data loaded into Excel I can do a proper analysis to determine speed and acceleration. I used it to test the variable length tuned pipe on the Pal. Having proper data allows you to make better decisions about what works and what doesn't. The other problem is that I'm to the point where the speedo is buried so it's hard to tell how fast I'm going from it.

keithw

scootercouple · Post by **scootercouple** » Sun Aug 10, 2008 7:07 pm

What sort of GPS do you use for this? I am an older Garmin handheld for backpacking. Also have a Tom-tom. Didn't think that either one of those could provide data after the fact about speed and acceleration.

PimpinSpree · Post by **PimpinSpree** » Sun Aug 10, 2008 8:02 pm

keithw wrote:You missed the point. I'm going to take the wimpiest, can't do nothin' to make it go fast scooter and kick some booty with it. My point of view is that if you take a faster scooter motor and put it in a Spree frame you don't have a Spree any more. You have an Elite or whatever with a Spree frame.

BTW, just how fast is your stock se50?

i dont' really agree with that. My spree still looks like a spree, feels like spree. The average person wouldn't even know anythings different. I wouldn't say "i got my spree to go 40mph, without clarification, but other than that, its still spree.

It only goes maybe 35 right now, but the acceleration is night and day difference

keithw · Post by **keithw** » Sun Aug 10, 2008 9:20 pm

I've got a Garmin 10xl and a Garmin 76s. When I got the 10xl it was the cheapest one that had data logging capability. It has the four pin plug on the back and you need a data cable and software to download data from it. The 76s is nice because it has a built in baro altimeter and records altitude in the data file.

keithw

keithw · Post by **keithw** » Fri Aug 15, 2008 8:58 am

Still waiting for the stock muffler. It has been shipped and should be here any day now. Finally got the carb sorted. The bi-starter plunger was sticking open. It runs sweet now.

I think I'll try something different for drestricting the muffler. The problem with drilling through the outlet is that it's hard to undo if you don't like it. My old 350 Honda had "decarboning" ports on the side of the muffler. They were covers held on by screws that opened into the first muffler chamber. I think I'll do something like that. Cover off, derestricted and loud. Cover on, stock and quiet.

keithw

Post by **noiseguy** » Fri Aug 15, 2008 3:46 pm

Like lake pipes.

keithw · Post by **keithw** » Thu Aug 21, 2008 1:03 am

My muffler arrived today. Unfortunately it has already been drilled. I've got it soaking in a lye bath to clean it up. What I will do is install it and do some speed runs. After that's done I'll tear into it and weld it back to stock and install the removable derestriction plate. Then I'll run it again to see how it does.

keithw

keithw · Post by **keithw** » Sun Aug 24, 2008 11:57 am

Here we go, finally getting started.

This graph is speed in mph vs acceleration in mph/second. The top speed was 27.5 mph at an engine speed of 8750 rpm. The speedo indicated 30 mph. This is with a stock 1985 Spree except that the exhaust has been drilled through the first two baffles. The next step is to cut open the muffler and weld up the drilled holes. Then I'll do another plot of a totally stock bike. When I weld up the muffler I'll add a removable opening to simulate a drilled muffler. This will make testing easier.

Thanks for making this sticky.

keithw

burnt_toast · Post by **burnt_toast** » Sun Aug 24, 2008 12:16 pm

Interesting project. Good luck with it, and thanks for taking the time to post such detailed results.

keithw · Post by **keithw** » Sun Aug 24, 2008 5:24 pm

Got to use two of my favorite tools, the angle grinder and the MIG welder. Here is what I found when I cut the Spree muffler apart. The exhaust first goes through a glass pack kind of thing. Then it enters a large chamber lined with mesh and what looks like fiberglass. Now it gets tricky. The first chamber has a tube going to the third chamber. The third chamber has a tube going to the second chamber. The second chamber has a tube going out the back. When you drill the exhaust through the outlet the first thing you hit is the baffle between the first and second chamber. This makes a straight path from the first chamber to the outlet. What do you hit when you drill farther? Don't know but I don't see how it could help anything.

Welded the muffler back together and added a bypass port, a big hole. It is drilled into the first chamber and is about 3/4" in diameter. This totally bypasses all the baffles and is about as derestricted as it gets. I will be amazed if I don't need to up the main jet when I try running with it open.

Yes, I know the welding is ugly. At this point in my life I don't care as long as it works.

Here is the cover in place. It's held with some sheet metal screws and has some neoprene gasket material under it. Not sure how long the neoprene will last but we'll see.

With the muffler back to stock it is really quiet. The bike doesn't seem to have quite the top end it did with the muffler drilled. I'll get it out in the morning with the GPS and see what it will do. For these tests I'm using the same piece of road at the same time of day trying to keep things consistant. There is about a 30 degree change in air temp between morning and afternoon. With a 2 stroke that is a player.

keithw

chevyguyjay · Post by **chevyguyjay** » Sun Aug 24, 2008 5:29 pm

thats exactly what the SE50 S muffler looks like inside. those 3 small pipes i removed out of mine and put in bigger pipes. thanks for posting those pics!

Post by **noiseguy** » Mon Aug 25, 2008 9:43 am

Good pic. I did that once with a muffler and saw the same thing with the rear baffles. What I decided to do was cut the muffler off between the first and second baffle. That way, it's just a chamber and outlet. You'll note that the main outlet from the chamber is 1/2" and properly sized, whereas the stock outlet is smaller.

I assume you torched out all the carbon while you were in there?