Spree bbk issues.

[Meatball]

So now we come to the issue of the bbk"s needing a unifilter to run right and bigger jets than what is supplied with the kits? The stock jet was 68 and the one supplied with the kits are 87. I guess Im buying a bunch of jets now to compensate for the unifilter's presence lowering the vacuum pressure? Anyone have a link to buy the jets I need? Sooner or later Im going to run out of extra parts to buy for the bbk to work correctly.

[benji]

As far as I know the jets supplied w most bbks assume your going to use the stock carb-and box. You don't "need" a uni filter, or an airbox or even a filter honestly. But if you don't smooth out the incoming air somehow then performance will be choppy and it'll be hard to tune. Btw, what needles/which notches are you using? Only changing your jets leaves you limited options to tune. I personally think that the best performance option is all stock stuff except a decent quality oem-style replacement filter element from malossi or polini or the like, and new reeds from the same, maybe even a larger version of the stock carb. 90cc jog and eton motors come w a 19mm stock carb, vinos come w 12mm. Both of those out perform our scooters by far haha. I run a 21mm pwk and ct mani w kx65 reeds, and I honestly think my bike would perform better w a closer to stock intake/carb/filter combo, but I like noise and high rpm haha.

Here's a trick- try the oem box w the jet supplied w the bbk and a fresh stock air filter. I bet it works well, maybe not street race ready tho.

[benji]

Here's another hint-you can buy an adapter to make a phbg carb work, allowing you aftermarket tunability in smaller packages. You can get a red dellorto in like 15mm, and get crazy amounts of jets, needles,needle-jets,etc.

[jakubman1]

So will i burn up an engine if i use the UNI filter???

My needle is at the standard setting

[Rip_City_Spree]

Jakub do you have a temp gauge? If not get one and you should never burn it up. Is a must with any bbk install in my opinion.

[benji]

^^exactly, or get really good at tuning. A uni doesn't always lead to a burnt up engine, just harder to tune. I put one on my oem motor cuz of the look and I didn't have an oem box. I've got one on my bbk now but it makes run funny sometimes, like w temperature changes.

[benji]

See?here's mine, runs loud n choppy sometimes but still runs good.

[Meatball]

[quote="benji"]I personally think that the best performance option is all stock stuff except a decent quality oem-style replacement filter element from malossi or polini or the like, and new reeds from the same, maybe even a larger version of the stock carb.[quote]

So Im buying new reeds and a carb too? My filter is brand new from noiseguy. Sounds pretty simple really. All you need for the bbk kit to run right is a unifilter, new main jets, new reeds, needles, a new carb, muffler, racing crankshaft, fuel tank, tires, platinum threaded drive belt, diamond encrusted mirrors and special edition polini seat foam....should run great! Plug n play!....ok, rant over

[Meatball]

Here's a trick- try the oem box w the jet supplied w the bbk and a fresh stock air filter. I bet it works well, maybe not street race ready tho.

This is what we started with. All stock everything except what was supplied in the kit. It didn't work and kept seizing so we made modifications as recommended by members of this forum. Buy this, change, that, tweak this, etc...as of now nothing is working. The only positive change has been the weight reduction to our wallets. Should be good for 2mph tho!

[Ultraliner]

I have soft seized mine once, due to a moment of inattention and possibly being a bit too eager too early into the break in process.

Everything was going fine up until about 40km in when I decided to try a short run on the main road. Doing it at 6pm as everyone was coming home from work was a bad idea as I soon had cars doing 80km/h coming up fast behind me. Not feeling too happy about this I went WOT for probably a good 750m to get out of the way ASAP and dive off onto the side road back up to my house.

Coming up to the corner at WOT, and in a hurry to get the f*#k out the way I dropped the throttle at the latest possible moment... Going from WOT to nothing doing about 65km/h(am running taz gears)at god knows how many RPM causes the main jet to all but close and relies on the stock pilot circuit to continue to try and fuel/lubricate my screaming, unbroken in 68cc beast.

Just after I got round the corner off the main road and tried to hit the throttle she made a big horrible hollow sound and stalled pretty suddenly. Started up and ran fine after a few minutes to sit and cool down and got me back home just fine, but upon pulling the cylinder off to investigate my foolishness there is some pretty bad scoring on the piston and cylinder below the exhaust port and corresponding area of the piston... And it now sounds like there is a handful of loose ball bearings kicking around in the crankcase when it's running

It still runs, rides fine and has plenty of power but would definitely annoy the neighbors if i rode it at night.

Im not suggesting you guys have done anything similarly foolish... Just telling my story

Am running a 48mm Taz BBK, 2x base gaskets with boost port cut out, metal head gasket, Main jet that came supplied with kit, needle clip in highest position, 32:1 premix(32ml of oil per litre of fuel)96 octane with Valvoline 2 stroke 'racing' oil, 2x 20mm holes punched into the airbox lid, one each side halfway between the center screw and the edge of the lid, stock exhaust, SB50 larger intake block and reeds and Taz gears.

Was having no problems with anything up until my moment of stupidity. I will get a new piston/cylinder when funds permit and break it in properly. Pretty sure I havent left anything out with my setup list. For now i'll keep rattling around the streets until it either seizes completely or fails to start due to a severe lack of compression

[benji]

You may actually have something rattling around in there, I did once. It was a 6mm nut, and the crank caught it and forced it out the case haha. Through the block, major hole.

WOT causes alot of problems w these scooters, especially on motors that aren't fully broken in or tuned properly. I'd avoid it until your sure things are running right. It really shouldn't take a whole huge list of parts to get a bbk working fairly well.

[benji]

Here's a trick- try the oem box w the jet supplied w the bbk and a fresh stock air filter. I bet it works well, maybe not street race ready tho.

This is what we started with. All stock everything except what was supplied in the kit. It didn't work and kept seizing so we made modifications as recommended by members of this forum. Buy this, change, that, tweak this, etc...as of now nothing is working. The only positive change has been the weight reduction to our wallets. Should be good for 2mph tho!

When was it seizing? After a run at wot? It sounds like you have a lean problem that won't go away to me... which usually means air leak somewhere. Or your pushing the motor too much too soon in break in.

[Meatball]

Pause this video at 2:54 and read. These are different instructions than what I got. This one says to mix 32:1 in the tank WITH the oil injection. Im running 32:1 with my oil pump deleted as recommended by Taz and many others. This guy did a follow-up video with about 400mi on his bbk install and does a few 35mph runs and it runs fine. Should I put my pump back on and mix 32:1 in the tank like he did?

https://www.youtube.com/watch?v=YC8j3vk1k4I

[jakubman1]

I do have a temp temp gauge I been using. These kits run hot maybe cause of break in. We should use 30:1 for break in and the 32:1 after 100 miles

[jakubman1]

What are temps suppose to be at with a stock spree??