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

[Meatball]

If youre figuring the TOTAL inlet volume and getting all scientific with it, theres also a small round hole on the bottom of the airbox. Its about the size of a pencil. Im assuming its a drain in case moisture ever got sucked into the box somehow.

[tazland001]

Right on. I am glad you are testing these kits out. You must have read my mind. These kits don't need to work for most people but all people. The directions have evolved over time. When I was growing up people who showed me how to work on dirt bikes always told me better to run rich than lean. That theory has never let me down. I have no clue what the pump delivers so like most I had to guess with my own testing on my spree. It worked for me and most of my customers but does not work for everyone. Don't worry about blowing the kit for testing because I can send you another BBK to help dial in the right ratio for air, fuel, and lubrication. 32to1 seems to work well on my spree. I really don't know what the stock oil pump delivers so I had to guess with testing.

I haven't got a chance to do any test with my spree. I got a stock carb and intake sent to me but just have to many other projects going on at moment. I would like to test to see if the pilot jet is to lean.We all know that the pilot control 1/4 throttle. We had 2 people on here in the last 2 month that had issues when the kit de-accelerates which causes lean conditions. Seems like the 34 pilot jet could be the culprit. A 34 is very lean for a 48mm if you ask me. Wheelman has mentioned this theory more than once and I would like to see someone test this theory. Also I think the main jet could be a little richer. I have run these kits with a 95 main and they run good. A fatter main could help on the lean plug chops. I did notice that that running a 95 is good but 97-100 is to rich and causes sponge.

Another thing is break in. Through out the years other mechanics will debate break in. Some people say to break a engine in fast and hard and others like me like the more slow approach. It has worked well for me but that doesn't make it right for all. Whatever your tests conclude is a good thing. I will revise my break in instructions according to the information provided on this thread.

I am also going to make some changes to the cylinder. Im not sure how far the changes will be but for starters I will use a thicker combustion chamber. I will also look at how tight the bores are. Considering how many kits I sell complaints are almost non existent. I have a lot of customers that I trouble shoot and they have great results. Crazy crazy. Like I said if you need more kits for testing purposes feel free to ask. I can send you 2 of them if you need me to. Test away and thank you for your service.

[eclark5483]

So.. what I'm thinking I'm going to do next, is this.. Since I know I was getting oil saturation, which, of course can run you lean (and it did). I know I'll be able to scratch that off the list of issues on the next run since I will be running 100% fuel plus the pump. That puts me in a position where I start playing around with less lubrication, but just GUESSING... it should hopefully not be too much of an issue as I don't plan on rapping out the engine to 11 grand or anywhere close to that.... I'm just looking for that magic 12 stoich.

I know it's not gonna rev out right with just the airbox and filter with no holes, but I still wanna get a reading of what A/F is as a baseline for the tape. And, I also wanna get a reading of where A/F is with the lid off, maybe push it to about 4 or 5 grand. From there, I know I will have to start with a certain hole size in the tape to be at about the exact same stoich that lid and filter will give. If I go low rev on the stoich, the fuel will be getting drawn from the pilot not the main. I wanna focus the hole(s) being poked in right around the inlet on the lid. My name isn't Bill Nye, but you would think putting random holes all over the place would throw things off a bit. I think it would be better to focus inlet vacuum then scatter it. So I wanna stay close to the inlet.

Once I find a sweet spot stoich, then I can focus on lubrication. I absolutely want to lubricate more, even if I can get it running good without premix, simply because the piston is new and it IS bigger so no reason at this point and time to think extra lubrication is NOT needed. I still wanna do a posterity's sake top speed run, but I'm not crazy enough to try that with just a pump on a non broken in BBK.

So this is the part where it gets REAL REAL hard... MATH

And not just any math, but unknown variable math. I have a 1 time fix for testing... I'll get into that in a sec.. but long term I'll need to calculate an exact. In this instance, those who run premix will have it MUCH EASIER..

I feel very comfortable with Brent @49ccscoot and his suggestion of running 40:1, But I am using a pump, that for the most part, there is no REAL documentation available to show what it actually puts out. Obviously I want to lubricate that BBK just a wee bit better then stock, but how much better? 36%

64:1 in the tank leaned me out and made it saturate oil out the tail pipe. I'm almost thinking 100:1 premix now, but that might be too little..meh.. who knows, not me?

But as a 1 time only temp fix, I look for ideal stoich, add oil in tank till it raises just a wee bit, take note of cc's used, do the math against a full gallon calculations later. Spree tank was what again? like 2/3rd's a gallon?

I figure once that starts happening in stoich, I'm golden because I have reached the point where I am starting to lean from saturation, but as the engine revs faster and up closer to that 11 grand mark, it SHOULD enrichen more on the stoich. And the piston, should hopefully be lubricated perfect for WOT..... Though I wouldn't think someone would want to drive WOT with the MLM though. The normal Spree can do WOT, and that's at what 7500?? 8000?

[Ultraliner]

This is some gold research you are delving into here eclarke, kudos to you

Regarding hole size increase for the airbox... I'm thinking along the line of existing airbox inlet orifice being Xcm2 at 50cc, the BBK is 68cc or 36% larger than the stock cylinder... Maybe making the total modified air intake orifice volume 36% more than stock would be something to consider?

The existing inlet is what I was pondering on last night. I was looking at images (stolen from eBay), and was thinking of this area here highlighted in red:

Image1.jpg

Image2.jpg

This is exactly the area I was thinking too. I'm by no means a scientist but would think keeping any additional holes as close to the existing inlet as possible would minimise/eliminate any potential air flow problems that having holes in different areas of the airbox might cause.

Pretty decent of Taz to offer up a couple of testing kits for you too!

[eclark5483]

Airbox currently has 2x 20mm holes punched through the lid. Scoot starts and rides fine but covering one of them up provides no obvious decrease in performance, however covering both causes it to not rev out properly.

This is exactly the area I was thinking too. I'm by no means a scientist but would think keeping any additional holes as close to the existing inlet as possible would minimise/eliminate any potential air flow problems that having holes in different areas of the airbox might cause.

So 2x20mm ya say, and covering 1 makes no decrease?

So I'm thinking 3x 10mm (1cm) holes, drilled in the following order, and represented by the spheres with green inside them:

holes.jpg (74.1 KiB) Viewed 7472 times

EDIT: I guess you could have fun with that and do 6 5mm holes or 12 2.5mm holes if you REALLY REALLY REALLY wanted to tweak the pressure while on meth. Make the sips just a bit bigger each time you drill the next hole.

[eclark5483]

And can someone check my oil ratio calculations math? Did I do it wrong? 128:1 is easy to achive using a syringe. You just go to 32:1 for 1 quart on the syringe, and put that into 1 gallon of gas. Repeat for a 2 gallon gas can, 3 gallon, etc, etc.. For now, he gets a 1 gallon gas can.

28.5:1 oil ratio using 64:1 tank premix if pump produces 50:1

33.5:1 is oil ratio if pump produces 70:1

The alleged range of lubrication I had, is anywhere from 28.5:1 oil up to 33.5:1

80:1 will give me 37.5:1 ratio if pump does 70

100:1 will give me 42:5 if pump does 70, 37.5 if it does 50.

120:1 will give me an oil ratio of 47.5:1 if pump does 70, and 42.5 if pump does 50.

So like, what is 2/3rds (Spree tank capacity??)) of 32:1? is it 32/1*2/3=44.5:1 if pump does 50, 49:5 to one if pump does 70? ??? Or does my math fail me?

I will be calculating from the tank and not a container.. I know, not really a smart move when doing oil ratios, but given the circumstances, I have to give it a best guess.

[Meatball]

I know the mystery here is the oil pump delivery amount and (I may be wrong) youre assuming the pump delivers a "set amount". The pump is mechanical and has no circuitry so its function is completely driven by the rotation of the crankshaft...which is constantly variable. Wouldn't that mean that the oil delivery would also be variable? Like if you spin that oil pump gear at 1800 RPM's (idle) it would pump "X" amount but spin it at 9000 RPM's (wot) and your pump would deliver much more.

[eclark5483]

I know the mystery here is the oil pump delivery amount and (I may be wrong) youre assuming the pump delivers a "set amount". The pump is mechanical and has no circuitry so its function is completely driven by the rotation of the crankshaft...which is constantly variable. Wouldn't that mean that the oil delivery would also be variable? Like if you spin that oil pump gear at 1800 RPM's (idle) it would pump "X" amount but spin it at 9000 RPM's (wot) and your pump would deliver much more.

Yes, I must ASSUME it is capable of a low 50:1, but start high in case it is 70:1 at given rpm levels.. or vise versa.. Then I would know a range I'll be in if I'm getting 50:1 or 70:1 on the delivery. Can't decide or know if it's one or the other..meh... flip the difference, guess on lowest, safest level.

I figure 120:1 looks safe, eyeballing 100:1 as well... decisions, decisions..

[Meatball]

Im thinking its needs a variable delivery system in the theory that at wot it would be sucking in a lot more fuel so it would also need more oil to maintain whatever oil/fuel ratio is required. There surely isn't a single ratio that would work for ALL rpm levels. That's why Honda made these pumps variable to what the engine is doing. The Elites have a pump that is operated by the throttle cable so that tells me that when you give it more gas, it needs and gets more oil. I think deleting an oil pump for these finicky Spree motors is changing the dynamics too much to maintain reliability. Its good that youre keeping the oil pump and playing with just adding mix to the tank. Maybe it needs one ratio at idle and a different one at wot? Who knows, its 1AM and Im tired..lol

Again, I may be wrong but it makes sense to me.

[eclark5483]

Hey guys, look what I just bought on eBay!! PERFECT for 128:1

128:1= 1 gallon of gas, and 1 ounce of oil

http://www.ebay.com/itm/141628716909.

Hope these will hold the injector oil without leaking. It's an easy way to gas up and remember... One gallon of gas, one vial of injector oil, mix and pour into tank.

At best that keeps me at 44.5:1, at worst, it gives me 49.5:1, that keeps me hovering at an estimated 47:1 at any given time if you average the high and low, and just divide by 2.

[Ultraliner]

Airbox currently has 2x 20mm holes punched through the lid. Scoot starts and rides fine but covering one of them up provides no obvious decrease in performance, however covering both causes it to not rev out properly.

This is exactly the area I was thinking too. I'm by no means a scientist but would think keeping any additional holes as close to the existing inlet as possible would minimise/eliminate any potential air flow problems that having holes in different areas of the airbox might cause.

So 2x20mm ya say, and covering 1 makes no decrease?

So I'm thinking 3x 10mm (1cm) holes, drilled in the following order, and represented by the spheres with green inside them:

holes.jpg

EDIT: I guess you could have fun with that and do 6 5mm holes or 12 2.5mm holes if you REALLY REALLY REALLY wanted to tweak the pressure while on meth. Make the sips just a bit bigger each time you drill the next hole.

Yeah man, the 2x 20mm holes in my airbox lid allow my scoot to run fine... Blank one off and it runs the same. Blank both off(running stock inlet alone)and it starts to starve under load at higher RPM's. This would lead me to believe that the increase in intake size lies somewhere between a 0 and 20mm diameter hole

After looking at your pics and realising that the intake holes are located in the lid, and then remembering I have a spare lid on the shelf I had a quick measure up tonight and worked out the intake size to be approximately 200mm2(10mmx10mm = 100mm2 x 2 = 200mm2)

Based on this a 36% increase on this size will be 200 x 1.36 = 272mm2). So a surface area increase of 72mm2 will yield a 36% increase in total inlet volume.

Given that the formula to calculate the area of a circle is A = pi(r2) I figured out that a 9.6mm hole has a surface area of 72.39mm2 - A = 3.142(4.8 x 4. = 72.39mm2

I reckon if you knock a 9.5mm hole somewhere close to hole No 3 on your drawing you'll be golden... It'll at least be 36% more intake volume, weather or not it'll actually work is a different story

I am inclined to agree with Meatball's theory on the pump delivering different volumes at different rpm's. Might be worth investigating if an orifice somewhere on the oil pump can be enlarged over stock by the magic number of 36% to deliver more oil for a given rpm.

You guys speak a different language to me with quarts and gallons ect. Google tells me that 1 quart = 0.95 litres and 1 US gallon = 3.8 litres. Can someone verify this for me?

[Ultraliner]

Why there is a small yellow dude wearing shades in the middle of one of my calcs is unknown to me...

[eclark5483]

I reckon if you knock a 9.5mm hole somewhere close to hole No 3 on your drawing you'll be golden...

You know what, I'm gonna go with that, not even gonna try tape. I'll just call it hole 1, then pic a corner and start whittling away at hole 2 size till I am at 9.5 there as well, rinse, & repeat if necessary.

[Meatball]

You could install an adjustable plug in your airbox lid. Sort of like the cap from a spice container with variable flow. As you twist the cap, the opening gets bigger/smaller to allow more/less flow. That way you can adjust on-the-fly when tuning. Might save you the headache of stopping and cutting/taping holes after every dyno run.

[eclark5483]

Yeah, I was kinda thinking the same thing. I have on old BBQ grill sitting in the garage. It has one of those slider vents on it.. Maybe even trim the one on top that's round. That would allow me to dial in the air, then lock it down with like a butterfly nut or something.. nah.. that sounds too easy... it's bound to fail. I'll think it over more.. cleaning the garage today and grilling some steaks.