Low dollar to high dollar budget estimates to use a 48mm BBK

Does your Spree/Elite already run great, and you're trying to make it quicker/faster? Need a monster motor swap? Discuss your ideas here.

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eclark5483
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Low dollar to high dollar budget estimates to use a 48mm BBK

Post by eclark5483 »

This is only my opinion, but I just wanted to give a little price point breakdown and different speed options that are available to get the most out of that BBK and to get it running HEALTHY.

Spin off topic from my BBK dyno testing thread.

So, one thing we can absolutely conclude, is that in order to run that BBK, you MUST address those intake issues. Perhaps Taz could possibly see into adding a supply of Kitaco intakes to his eBay store line up. Perhaps Brandon could get a low cost Mikuni kit to offer. Perhaps an adapter combo fitted for the Spree carb. But an intake solution is an AT MINIMUM must, when using a BBK.

That's the minimum I would go.

Currently as I'm looking, I'm showing it's gonna run somebody roughly $170 AT MINIMUM.

Don't know or care how frugal you are, it is what it is, and if you think about it... it's really quite cheap.

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TAZLAND001 (chopchop*123) 48mm BBK
KITACO INTAKE
CP adapter
Pod filter
From there, you now have options. Spend more money, or make do with what you have are the main 2 options you should always pay attention to, but I guess to split it up a bit, starting with the intake portion.

So OK, you got the reasonably priced Kitaco, what can you do for free or at cost to it to improve performance. This free, or possibly paid for service would consist of...

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Ported reeds
Ported intake
SB50 reeds (preferably ported)
BBQ UR' MUFFLER.. DRILL IF NEEDED TO REMOVE WASHER RESTRICTION.
Delete oil pump and switch to 32:1 premix (recommended)
If you keep the pump, run 96:1 in the tank, 80:1 for break in.
From there, you'll need to cough up some more of your McPaycheck. If you want your Spree to be quick, use a 12T low gear. This might be more ideal for semi off road use. If you don't have one, they go pretty cheap on that one auction site that treats your fun like what they have to offer is gold. The 13T gear is a good all around pep on the pickup gear and top speed is an easy 35+. Great day to day setup for most people.

So then your next option for gears anyway, should only be the aftermarket 15:81 gears.

This will slow down your take off experience, but the power in the BBK makes up for it. You'll get better gas mileage out of that same 35mph, the BBK will not be under as much RPM stress to get you there, and you'll even have a little oomph to spare to push you up past 40.

I guess I have 1 other recommendation and that has to do with break in. Keep it within it's powerband range during break in, do not exceed this range while breaking in.

8,000rpm MAX while breaking in. Don't care if it will now do 9, 10,11, or even 12k. Keep it in it's power band.

To give you a rough guess estimate of what that would more then likely be, I'll base it off available gears

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12T: NO MORE THAN 20mph during break in
13T: NO MORE THAN 25mph during break in
15T: NO MORE THAN 30mph during break in
I have no opinion either way when it comes to how you choose to break it in. Baby it.. slam it, heat cycle it, whatever.. Too many different opinions on that, no need to offer mine, I just offer....stay in the power band.

From there you start spending money on things like carb upgrades to like maybe a Mikuni or Polini. As well as the next big investment and going with the MLM pipe. Or, get one fabbed. Whatever's in your budget I guess.

So you could take the "upgrade" path many different ways, alot of it, you can do if you can turn a wrench.

Again, this is just my opinion of a low cost to high cost analysis. I won't go any farther in calling anything extra listed or optional as a "MUST HAVE" Other then the BBK, Kitaco and adapter.

japan.webike.net , Scooter Swap Shop, eBay.. This is where you will find those 3 MUST HAVE parts. Amazon also sells the Kitaco. All 3 places offer the upgrade parts and options.

All tallied, you may end up spending close to $600+ dollars if you go all out !!!

All parts with links to some of their respective vendors, can be found here:

viewtopic.php?f=1&t=33591&p=295922#p295922
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Last edited by eclark5483 on Sat Dec 24, 2016 6:03 pm, edited 5 times in total.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by Gearhart »

I have installed and tuned a spree big bore kit with no other upgrades other than the bigger main that comes with the kit and it runs amazing and has over 1000 miles on it. It just takes the ability to tune. The instructions with the kit tell you to drill three holes in your airbox which is why everyone is seizing these left and right. It doesnt need that much more air. The spree I installed it in has no temp gauge and has never had one. I tuned it based off the plug. I have seen my buddy wide open throttle this thing for 10 miles straight and it is fine. 2 strokes are very picky with the fuel/air ratio. So IMO before you go installing big bores, know how to tune or read up and learn how to tune.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by eclark5483 »

As far as keep the pump .vs ditch the pump goes, Keeping the pump would probably only be useful if you are staying with the stock carb. You wanna let that stock carb deliver as much gas as it was intended and the oil pump would act as a helper. When you switch to a larger/better carb, that's when you should also consider deleting the pump and going full blown premix. The better carbs can handle the extra oil in the tank. As well as other gained advantages.. So really.. only keep that stock carb if you're living on paperboy wages. You don't HAVE TO, but wow, think it through first and either do it, or keep it as a TO DO later on.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by Waffles97 »

Could someone post a link to Taz's ebay store?
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by eclark5483 »

graphite9 wrote:good write up. remember you need a air box with stock carb, or an aftermarket carb.
Yes, and I should clarify a bit. If you keep the stock airbox with the "AT MINIMUM" setup, you might have to modify the coupler between the carb and airbox a bit..maybe not, not sure how far it changes the original position of the carb over stock to connect to the airbox, but it will change slightly... Then drill 4 or 5 (start at 4) 3/8ths inch holes in the airbox lid next to the inlet.

Image

As mentioned by Gearhart, the BBK does NOT need much more air. The airbox is not the problem, pick the hole number and size wisely, start small.. it is the intake from the carb to the engine, and this issue should be addressed in the "AT MINIMUM" configuration with the Kitaco intake and CP adapter. The airbox is your tuning friend, it will give you a better stoich then a free air filter will.. The #90 mainjet that comes with the BBK will work just fine for you, consider using a #92 if you remove the airbox and switch to a pod filter. Remember, almost every bike needs a boost in that jet when switching to a free air filter. A better intake will not change that fact. I'd make sure to specify to Taz which jet you want him to send based on your application and preference.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by eclark5483 »

Also, to clarify on gears a bit as well. If you have an 84-85 Spree, you more then likely have a 12T gear. Real expectations for a BBK is that it will do 30. Iowa Sprees also have the 12T gear. If you have an 86-87 non Iowa edition Spree, you have a 13T gear and can expect 35mph from the BBK. A BBK does not increase your top speed, it only increases the speed you get there. Anything exceeding that is all tuning and upgrading.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by MrJumps »

A bbk can increase top speed if the ports are mapped to ride higher. Thats a question for taz though. Speed is rpm variable, gears just transverse the rpms. Being a 1 speed your literly getting 12 to (44?) Or what ever it is out the motor.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by eclark5483 »

When using an aftermarket carb, adjust your idle speed to 1800 rpm +/- 100, to match stock rpms.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by eclark5483 »

Simple hack to fix alignment problems between stock intake and Kitaco/adapter swap when connecting that stock airbox... just cut here and use duct tape to space the gap you need.

Image

Might NOT be needed, I have never personally tried it since I opted for the Polini.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by eclark5483 »

My recommendation for a "MINIMUM" setup configuration would be:

Tazland001 BBK
Kitaco Intake
CP Adapter
Keep stock carb and oil pump
run 80:1 (1.6oz / 47.31ml, per gallon) oil/fuel mix for break in
run 96:1 (1.33oz / 39.43ml, per gallon) after break in
keep stock air box
drill 3-3/8th's inch hole above airbox inlet, tune from there.

OR

remove air box, increase jet size, go with pod filter.

Recommended: AIRBOX.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by tazland001 »

I appreciate all the help in the area of fine-tuning these BBKÔÇÖs. I will revise the instructions on the holes in the stock air box lid as recommended in this thread.
I do want to add the stock carb works fine. I walk a lot of my customers through the process and they have very good results. Most of my customers use a BBK and still ride it as a spree with a little extra spunk. They use it for running errands and short distance travel. Its when the kits are pushed to the limits is when they fail. Not all fail but some have failed as mentioned in prior threads. That being said I am making changes to the kit.
The porting is 178/143 and that does not include the boost port. The transfer ports are too high. I have been talking to 1man8scoots about this and he told me he would make me a new port map with the correct changes. He suggested porting of 182 136/134 timing. I havenÔÇÖt heard from him in a couple weeks but it is the holiday season. I am an engine builder so port work in not my specialty but I have done a lot of reading on this recently. I do some port work but not at the level of the pros. That s*** will make youÔÇÖre your brain bleed. Lol
I am checking into better quality piston and rings+ a coating on the skirts and crown. I have done research on this as well and I can replicate what the better brands use. Also I will make the cylinder walls thicker. That wonÔÇÖt do much for heat but will add some piece of mind for damage to the skirt of the cylinder.
I am going to bring in larger pilot jets. When I run a pwk carb on my spree I run a 102 and a 42 pilot. If we can run a 42-45 pilot on the spree carb I think it will help a lot. I also want to check the id hole on the stock carb and compare it to the id hole for the pilot jet on a pwk carb.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by tazland001 »

I just wanted to add. My business is just a hobby. But regardless if this a hobby I still want to sell the best parts possible so I once again I am grateful for the help
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by eclark5483 »

tazland001 wrote:Its when the kits are pushed to the limits is when they fail.
My research has shown, the key limiting factor, is the intake. This is why I recommend using a Kitaco intake with the CP adapter.

INTAKE:
http://japan.webike.net/products/373376.html
or
https://www.amazon.com/gp/product/B002TUKNDS

Adapter:
http://scooterswapshop.com/collections/ ... rb-adapter

ENTIRE INTAKE KIT/Adapter INCLUDING Mikuni CARB:
http://japan.webike.net/products/375578.html
*NOTE: Pilot jet is listed at 27.5, extra jets can be purchased from http://www.treatland.tv/mikuni-s/81.htm and other vendors.

The fault is not with the BBK, but rather with the intake system Honda designed for a stock Spree piston. Once you correct this problem, you'll find that the stock carb works beautiful with just a simple jet change to the included jet in the kit. As Taz said "the stock carb works fine". A Mikuni/Polini/etc carb should only be considered a PERFORMANCE upgrade, not a necessity.

After break in, you SHOULD be able to run the BBK wide open throttle provided you use the proper intake. Without that intake, I really wouldn't recommend a WOT run for very long.

What's happening is the BBK can't take in enough air/fuel mixture from the venturi. No amount of holes in the airbox or even a free air pod filter is going to help... in fact the more air you try feeding it from the carb, the more likely you are gonna end up burning up the piston. The problem needs addressed at the intake.

Since you can not buy a better intake for the Spree, you have 2 options... Hunt down an intake from an SB50 Aero (very hard to find), delete the oil pump & run 32:1 premix in the tank... OR... simply replace it with a Kitaco intake which is basically a performance intake made for a Honda Tact (Aero in the US). The Kitaco intake is made for Big Bore Kits. YOU CAN RETAIN THE STOCK OIL PUMP WITH IT.
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Re: Low dollar to high dollar budget estimates to use a 48mm

Post by MrJumps »

I wpuld highly advise to premix if looking 5o change preformance on a bike. Its too risky to rely off a pump that can fail and over oil and cause a bike yo run lean, build up carbon ealry and even lead to filling your crank case with oil and leaving you stranded. The oil pump works amazing for stock use, but in my finds it sucks power thats noticeable too me anyway and is another part that can fail. The whole point of a bbk the spree is to gain the umph but I believe at any cost of performance you loose economic pleasure. - Jumps
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