Getting the Tazland BBK, GEARS, + MLM ran on a dyno

[eclark5483]

Although.. with an adjustable cap, there is an advantage. If I find I have to remove the BBK for whatever reason later on down the line, I can revert back to normal pressure on the fly... hmm..

[eclark5483]

Oh, so people know, Brent from 49cc, thinks something screwy was going on in videos 2 and 3 with the RPM reading. And it is a bit odd.. 35@4300, vs 35@8800 in videos 4 and 5?

Yeah that is crazy.. If you listen to what Shawn says in video 5 (maybe it was 4), he says we lost I think it was 1 horsepower, and we were at half torque with full air. If you freeze frame, you can see HP that run was like 2.87 or 2.97.. hard to tell from the video, so add 1 more horse to that, then peak so far is 3.97, but that really doesn't explain why such a huge RPM difference? mis-firing/fowling plug?

[eclark5483]

First hole?

hole proposal.jpg (97.3 KiB) Viewed 7741 times

[Ultraliner]

First hole?

hole proposal.jpg

Right on, smack a 9.5mm through there and I reckon you'll be off to a good start

Have you done any testing of your own with the stock airbox lid and filter fitted?

[eclark5483]

No, the bike is up at SS at the moment.

[benji]

For longevity reasons, I'd try to get the stock bore to work for him w the pump, or teach him to premix. I put in 4oz of oil everytime I fill up, not too much of a hassle, and it's reliable and does 45-50 w a bbk. But it's variated. A non variated spree motor is gonna try alot harder at those speeds, even w gears. Btw, it's also possible to do some port work on the oem head and make it quite a bit faster.

I get the autism/special needs thing. I had an uncle w autism, and he was very methodical. He loved the "sims" game for his computer (in the 90s btw) cuz it had so many rules he could follow. But you can't take care of your kids forever, and after your gone he'll need to be able to work on this thing regardless. I'm not sure of his needs, but I would show him everything about the scooter, regardless of the tune/configuration, and get him a shop manual for it. If he can work on it, he'll do better than if he cant.

And maybe buy a couple extra sprees and some parts while you can anyways, there still cheap might as well stock up!

[benji]

Or maybe show him an aero 80? Those are pretty 80s styled and do well at 45 stock.

[eclark5483]

For longevity reasons, I'd try to get the stock bore to work for him w the pump, or teach him to premix.

That's what I bought those vials on eBay for.

vial.jpg (35.24 KiB) Viewed 7723 times

I want a bit more lubrication, but of course, don't wanna go into saturation again. So after we get stoich dialed in, I'm gonna dump 20ml (2/3rds an ounce) of GN2 injector oil into the tank. If I'm calculating correctly, this will give me 128:1 premix ratio, which, when added to the pump is 44.5:1 if pump does 50, 49.5:1 if pump does 70.

It gets me a little better lubrication over stock to take away some of the worry. And will be easy for him to figure out how to do on his own, No need to measure, just fill up a bunch of these vials and put them away for when you need one, pour just 1 into the gallon sized gas can. And if he goes over a bit on the 1oz fill line in the vial... should be no big deal at all. In fact, will be even better because he'll end up bumping up lubrication just a bit if he does an "oops".

[eclark5483]

Here are some vials (85:1) that will take it down to 33.75:1 if the pump is doing 50:1, and 38.75:1 if the pump is doing 70:1

http://www.ebay.com/itm/381437990199

[MrJumps]

Looking good, glad to see some progress with some numbers to it. Follwoing along with you trying to modify it for my need of the spre tank to premix 32:1 in the bike.

[eclark5483]

Looking good, glad to see some progress with some numbers to it. Following along with you trying to modify it for my need of the spre tank to premix 32:1 in the bike.

Yeah, for sure people should look at it for their needs and calculate. I'm going high on the oil, but obviously some people need 32:1 There are probably pump fed Sprees out there who would need a 32:1 while others only need 50:1 or better. Maybe the difference is I have an NQ50I ?? Who knows, what does it matter?

The math I am using is VERY simple. You just take one ratio and add it to the next, then divide by 2 twice.

Example: 50+64= 114, 114/2= 57, 57/2= 28.5:1 ratio.

[eclark5483]

Wow, here's some oddly coincidental facts.If the pump, by some oddball chance, actually did 32:1 all along, and I didn't know it, and nobody else ever knew it either, adding an additional 128:1 ratio in the tank with the pump, gives you 40:1 oil delivery. Exactly the number Brent @ 49cc said it should be at.

WOW!!

And if it does in fact put out 32:1, that means with the 64:1 I ran in the tank, I had an astonishing 24:1 oil ratio going on.

Guess I'll probably never know for sure, but I do know it was enough oil to fowl out the spark plug.

[eclark5483]

Well, just got done with the next set of runs, and.... WE HIT 40!!!!

I have the videos uploading right now and will post them as they get published on YouTube.

I tried out my 128:1 in the tank theory, seems like I was right on the mark.

What we have concluded on this set of tests is this:

YES, we more then likely do need not only a larger main, but a larger pilot as well.

The lubrication was perfect this time, no excessive smoking, no saturation after I gave it a 128:1 adjustment in the tank.

Tests were again run pretty much the same way as last time. Air box lid on, filter in, then lid off filter in. Then we did hole 1, then 2, then a 3rd. After we collected all the data from those runs, we did a bump up in the oil so we could test higher RPM ranges.. will get to all that in a bit, but for now, while I'm waiting for videos to upload, I'll post this..

These are printouts from the best run

[eclark5483]

OK guys, here is the dyno run that corresponds to the graphs I just posted.

This was the best run with the Spree giving everything it had to give (for now).

It was ran with 128:1 in the tank, Dyno fans on to keep it running cool just in case... NO AIRBOX LID, NO FILTER. This was a free air run.

I'm gonna be a bit busy here, so I might not get the other videos uploaded till later today. I urge people to not only watch the video, but listen to the conversation Shawn and I have about what has been happening.. Enjoy

https://www.youtube.com/watch?v=4IzNlbWuawI

[eclark5483]

Ya know... I think I'm REALLY starting to eyeball that Polini now. The Taz BBK has ALOT MORE to give.. Baby steps for now though. I think today we at least are able to get passed air box .vs pod filter. The victor this round, goes to POD FILTER!?!?!? Unfortunately, I forgot to grab it when I went up to the shop today, so NEXT TIME!!! Need to get those jets bumped up first.