44mm or 48mm BBK

[spewya]

The 1986-87 Sprees, all the SB50s and the 1985 Aero 50 all used the same gasket so the reed block will fit. The 1984-85 Spree shows a different gasket but I know the '86-'87 gasket fits on the '84-'85 Spree, so yeah, they should all fit.

I would have to think about the reed thing.

ok let me know if u decide u wana sell a set ..

[thistleb]

So I bought the 44mm kit from Taz. Installed the jet that came with the kit and drilled 5 1/2" holes in the filter box top. Everything went together well and it fired right up. Have about 1/2 hour of run time on it now. I didnt change the a/f adjustment on the carb from where it was with the stock bore. Should I ?

Nice kit Taz.

[JJ Joseph]

i have the 44mm kit and i am pleased with it, my son rides it and seems to like it. that said i was reading in another post that to run the 48mm it will need a bigger carb. can you elaborate. if ypu do tell us what is needed to get full potential out of it.

Just for running up and down hills, the stock carb, even with a 48mm kit, is just fine. You may need to try different jets, but nothing more. The stock carb has the electric bystarter choke, which is a no-brainer. The after-market carbs can get pretty weird! This would be a nice Spree!

[Bear45-70]

i have the 44mm kit and i am pleased with it, my son rides it and seems to like it. that said i was reading in another post that to run the 48mm it will need a bigger carb. can you elaborate. if ypu do tell us what is needed to get full potential out of it.

Just for running up and down hills, the stock carb, even with a 48mm kit, is just fine. You may need to try different jets, but nothing more. The stock carb has the electric bystarter choke, which is a no-brainer. The after-market carbs can get pretty weird! This would be a nice Spree!

There is no point in getting the 48 mm BBK if you are going to restrict it to 44 mm BBK performance with the stock carb and exhaust. Why waste your money? Taz is soon to have on the market a bigger carb and intake for the 48 mm BBK. An exhaust should not be to far behind it. Doing the 48 mm BBK with stock carb would be like buying a supercharged Mustang and then put the stock throttle body back on it to choke it down to stock engine performance. Why bother?

[fastplastic]

Just for running up and down hills, the stock carb, even with a 48mm kit, is just fine. You may need to try different jets, but nothing more. The stock carb has the electric bystarter choke, which is a no-brainer. The after-market carbs can get pretty weird! This would be a nice Spree!

FAIL!

[dyehardfan]

How big of a concern is overheating with the 48mm kit? I have almost bitten the bullet and spentthe $$ for the kit, but I live in the south and it's averaged 100 degrees the last week and will next week. This is a pretty important decision on what I am going to do. IF I go with the 48mm I am definitely going to put Taz' intake on there and will purchase the exhaust as soon as possible. In the meantime I plan on opening up the exhaust to clean it out and put 1/4" larger pipes in their place.


But back to the overheating? Is this a serious concern if I do normal maintenance and keep the oil level at the proper ratio? Really want the extra power the more I think about it, but don't want to have to deal with engine seizure on a ride to or from work.

[tazland001]

Break the kit in and your good to go. The break in is soooo important.

Taz

[JJ Joseph]

How big of a concern is overheating with the 48mm kit? I have almost bitten the bullet and spentthe $$ for the kit, but I live in the south and it's averaged 100 degrees the last week and will next week. This is a pretty important decision on what I am going to do. IF I go with the 48mm I am definitely going to put Taz' intake on there and will purchase the exhaust as soon as possible. In the meantime I plan on opening up the exhaust to clean it out and put 1/4" larger pipes in their place.


But back to the overheating? Is this a serious concern if I do normal maintenance and keep the oil level at the proper ratio? Really want the extra power the more I think about it, but don't want to have to deal with engine seizure on a ride to or from work.

Overheating is not a problem. Drilling out your exhaust will lose all your power gain, if I'm reading you right. The Taz intake is overkill. The 48mm jug generates enough extra torque with the stock carb to do 30mph uphill. You'll just be limited in max rpm. Do it in steps and debug everything as you go. Leave the intake & exhaust until the last. The Spree as it sits is not a great machine for over 30mph (terrible shocks, brakes, tires, lights, etc)!

[dyehardfan]

How big of a concern is overheating with the 48mm kit? I have almost bitten the bullet and spentthe $$ for the kit, but I live in the south and it's averaged 100 degrees the last week and will next week. This is a pretty important decision on what I am going to do. IF I go with the 48mm I am definitely going to put Taz' intake on there and will purchase the exhaust as soon as possible. In the meantime I plan on opening up the exhaust to clean it out and put 1/4" larger pipes in their place.


But back to the overheating? Is this a serious concern if I do normal maintenance and keep the oil level at the proper ratio? Really want the extra power the more I think about it, but don't want to have to deal with engine seizure on a ride to or from work.

Overheating is not a problem. Drilling out your exhaust will lose all your power gain, if I'm reading you right. The Taz intake is overkill. The 48mm jug generates enough extra torque with the stock carb to do 30mph uphill. You'll just be limited in max rpm. Do it in steps and debug everything as you go. Leave the intake & exhaust until the last. The Spree as it sits is not a great machine for over 30mph (terrible shocks, brakes, tires, lights, etc)!

What I meant by drilling out my exhaust was to open it up like so:

muffler_disssected.jpg (194.29 KiB) Viewed 3167 times

(credit: viewtopic.php?f=16&t=6510&start=15)


And replacing one or more of those inner pipes with a larger diameter pipe. Are you saying that I will lose too much back pressure by doing this and thus losing power?

What suggestions does everyone have regarding modifying the stock exhaust until a tuned exhaust is available. I am looking for peak low to mid-range power that will open up when needed. I understand that I am going to be losing some low to midrange power swapping the stock gears out, but I don't think I'll see ANY performance gain using stock gearing with the 48mm BBK, will I?

[thegoldensb]

I just bought the 48mm big bore kit from taz and after stumbling upon this it makes me question if I should switch
to the 44mm cause I have stock carb and exhaust