BBK questions

[Bear45-70]

The one I have is a physical twin in external demensions to my '84 and '86 Spree jugs.

[hammer]

What was the end result after the sb50 jug swap in the Spree?

I don't want to test several jugs if I can help it. If I can find a combination that will give me some decent bottom end. I am not looking to run 40mph. An improved bottom end and still run 30 will be excellent.

The scooter for my daughter who uses it at the University of Arkansas campus which is loaded with hills. She has a 1986 Spree now. The scooter perfect size for her but lacks some guts.

I thought I was on the right track when I found a very low mileage 84 with the lower ratio gears. Then I find out that 84 are known to be sluggish after boring a 84 jug.

I didn't want to go with a TAZ 44mm kit because they sounded a little difficult to tune. I thought maybe a OEM jug and a more conservative 43MM might be a better combo. I think it still might be if I choose the right jug.

[edgargonz]

Guys I know where the reed valves are! I know where the needle valves are.

The 84 spree jugs are different than the spree 86 jugs. What is the effect of that difference on the spree's bottom end performance?

If you know please say so......... if you don't know don't bother.

My god it was a typo.

Take a deep breath....................along with alot of help on this site you will get razzed..........enjoy

[Bear45-70]

What was the end result after the sb50 jug swap in the Spree?

I don't want to test several jugs if I can help it. If I can find a combination that will give me some decent bottom end. I am not looking to run 40mph. An improved bottom end and still run 30 will be excellent.

The scooter for my daughter who uses it at the University of Arkansas campus which is loaded with hills. She has a 1986 Spree now. The scooter perfect size for her but lacks some guts.

I thought I was on the right track when I found a very low mileage 84 with the lower ratio gears. Then I find out that 84 are known to be sluggish after boring a 84 jug.

I didn't want to go with a TAZ 44mm kit because they sounded a little difficult to tune. I thought maybe a OEM jug and a more conservative 43MM might be a better combo. I think it still might be if I choose the right jug.

The SB jug is sitting in the bench right next to the Spree engine. Right where it was when I had some health issue and a stay in the hospital interrupt my plans. So I can't tell you if it is better or not.

OH I am going with the 43 mm overbore also but until the doc cuts me loose, I am on restricted duty and can't play with my toys.

[hammer]

I have a new 88 sb50 jug and std piston ordered and will be shipped soon. For the price of the new piston and rings I am going to try the std bore for now. If I am satisfied with the bottom end performance I will not overbore. I really want to stay with an unmolested airbox if possible and keep jetting and any changes to the carb at a minimum. I will use the 43mm stuff on another spree project. Only need a little bit on the bottom end to be satisfied.

I will pass on my results on to you if you like. If the parts arrive soon enough I might know something by the end of next week.

I struggled with deciding between sb50 and the sb50p jug. I hope I made the right choice. Since the sb50p was restricted I went sb50 with the hope that the stock porting supports an unrestricted motor better. I will smooth out any rough edges but nothing else.

Best wishes on your health issues and hopefully soon you can get back to your projects.

[Flea_Biskit]

I believe that the gear ratios change with the year of the spree's have you thought about that?
But if all else fails

Dude swap in a dio!!

[Flea_Biskit]

but i also believe that taz's kit would solve your problems its cheaper than a dio swap also it would be fun we will help you with the tuning there is not alot that can be done to the nq50 good luck

[eliteguy50]

I struggled with deciding between sb50 and the sb50p jug. I hope I made the right choice. Since the sb50p was restricted I went sb50 with the hope that the stock porting supports an unrestricted motor better. I will smooth out any rough edges but nothing else.

Yes, the sb50 was the better choice. I don't have experience between swapping spree jugs but swapping sb50 and sb50p I do have experience with. The sb50p hits just slightly sooner but the usable power is better on the sb50. Unless you spend all of your time between 8 and 14 mph, you made the right choice.

[hammer]

I have a TAZ BBK and TAZ gears already. I would like to at least read one post on this thread where anybody that has installed a TAZ kit that has not had tuning issues and is completely satisfied with the results. There always seems to be a problem getting the balance right.

This scooter will end up 500 miles from me with my daughter and I can't just stop by and work on it when it won't start.

If you read the rest of this thread you will know that I have intentionally picked and 1984 engine base with the lower ratio gears to work with. It makes no senses to me to add a set of TAZ gears when I want a better bottom end and don't care about increasing the overall speed of the scooter. I have already installed a set of 2.75 tires and I may elect to go back to a 2.50 tire if need be to maintain some guts.

The reason I have choose to work with the spree is the dry weight of the machine. If need be my daughter can pick the thing up and drag it around. She is just a little thing but the fact that she weighs more than the scooter does seems to work well. Also the cost factor. I am not buying $2000 machine that will be setting around campus unprotected from the weather. I could buy one of the expensive 2 stroke Italian scooters but I don't want her whizzing around campus at 50mph either.

The TAZ parts are very attractive and I look forward to using them on a project soon. That why I bought them. However I don't think it is the best combination for this project. If I can't get the results I want I have the kit here to put on. Swapping out the piston and jug only takes a few minutes but the break-in and tunning issues on the TAZ kit could take weeks.

[hammer]

Okay I got the stock sb50 jug, piston and rings. The stock sb50 exhaust runner was a for sure bigger than the 84 jug I used on the 43mm bore. I couldn't tell much difference besides that. The exhaust port might be a hair higher but not very much. All I have to measure is was a steel metric ruler. Looked like it was 1mm higher. I went ahead and ported the exhaust port made it little wider and leveled out the top edge. Smoothed out the entire exhaust runner Also took about .010 inches off a 86 head.

Results are very nice. The bottom is much better but just a tiny bit more will do the trick. The mid-range is excellent. There is more top end too but haven't laid the wood to it yet. I am sure the 2.75 tires are killing some of the bottom end. But since my daughter weighs 115 pounds I think it will workout okay.

Had a 68 jet in with all stock airbox with a new honda filter and then went back to a 60 and the scooter came alive. I am using a clean 1986 exhaust. I have a clean 1984 muffler I might try to see if the bottom end improves.

I might try a thin shim between the front pulley halves. I have a brand new belt on there now. The bottom end might even improve a when the new gets worn off the belt. The more I think about it the shim might just be the ticket in fact.

I have 3 good running Sprees and this one will out run all of them just as it is now. Just a little tweaking and I think I will be there.

[Spreetard]

...back to a 60 jet?? how's the ol' plug chop look? honda-san decided 68 was the way to go for good reason methinks... and a leaned out engine will scream till it melts. i bet your cht is sky high.

[hammer]

Keep in mind this motor is basically still stock. Mild port of the exhaust and very little shaved off the head. Sb50 reeds,manifold and jug. I have a sb50 carb coming that I am going to see if I can use before I get into some serious tuning.

I think I will may hit something between the 60 and the 68. But with the 68 was too rich at the present time and the motor was 4 cycling. Not 100% sure the 68 was indeed a 68. Might be something that been drilled. Only got a few minutes on the motor. Years of Go Kart racing suggest it not running lean yet. Has a little blubber and plenty of smoke.

I will work with it more the next few days. Basically just done a shake down so far.

[eliteguy50]

What spark plug are you using?

[hammer]

I am sorry guys . I got to thinking about this after I went to bed. My fault for getting everyone all excited.

What I should said was I put a known to be stock main jet in. I thought the number was a 60. I think now it is a 65 or a 68. The 68 I started with was most likely one that I had drilled in the past.

[eliteguy50]

I think now it is a 65 or a 68.

Yes, those are the stock sizes for the sb50.