Top Speed Run Today!

[Mike Bean]

I had a chance to strap on the GPS today and take it for a couple of wide open runs. The road I had was on a slight curve but I am pretty sure I was close to top speed.

The fastest I could get the BSR to run was 44.1 MPH. I know BSR's with rider are not the most aero dynamic rides around, but I expected at least 50 MPH. :cussing:

I am going to look into making sure the engine has the correct timing and set the valve lash also. I think I can hear a valve very lightly tapping in the top end.

The plug color was good so it is not a carburetor problem.

My questions is...Many people have posted about speeds their BSR's have actually run, has anyone actually clocked this other than guesstimating? After running today, I don't think my 6.5HP with the TAV2 was really going 40 MPH. It seemed much faster today than before.

Mike Bean

[elvergon]

Well, you gotta accept that because TAV2 have variable "gears" (for calling it that way) it is pretty nice for getting the speed and torque both at the same time. In fact if it is correctly calibrated it should be better than gears, cause you´re always using the maximum horsepower of the engine and relationship is changing. Probably you know about this. This is where you might want to decide if getting a smaller or a bigger sprocket depending on your speed/torque needs. You got to realize that you might be having a little more than 10 hp in your engine ( dunno much about older engines and their efficiency) but right now it´s probably 10 cc = 1 Hp. SOoo you could put that speed up or get more torque for hauling things ;)

It also depends on what cruising speed you like.

It´s up to you, let me know about your decition with the sprocket. And hopefully after checking the engine you´ll find something that makes you go faster ;)

By the way....It would be nice if you posted a thread when you check the timing and all the internal parts stuff. With lots of pics =)!


Good luck

[Mike Bean]

Elvergon,

My engine has 4 gears, so I would assume the additional horsepower and gearing with a rear sprocket 12 teeth less than the one with the TAV2 that this combination should run faster.

Something is holding it back if the old combination (6.5HP w/TAV2) was running 40 MPH. I never clocked it, but I would be interested in hearing from others that have actually clocked there BSR's.

The engine definitely has a lot more pickup and power. I was cruising in 3RD gear today and hit the gas and lifted the front end. I was never able to to that at cruising speed with a TAV2.

I will start looking into the engine stuff next week and post what I find out and try some more speed runs next weekend.

Mike

[freak]

Does it sound like the engine is reving up far enough. I would think with that engine , those gears and as small as those tires are ( compared to a atv or bike ) it would top out higher then on a bike. Or am i thinking that backward. I've been cleaning out the addict all day and man is it hot. I don't think i'm thinking rite. LOL !!

[Mike Bean]

Freak,

The engine sounds to be reving pretty good on the high end. I think I need to hook up a tack and see where I am at.

Does anyone know what kind of rpm range a 1983 Suzuki ATV had?

The engine is definitely not having a problem getting going. I do not think I can get any smaller on the rear sprocket unless I have a custom hub made and the hub I am using is pretty small already.

I am going to look into tuning the engine first and making sure it is running good. I also need to get an air cleaner on the carb because at speed I am sure the engine is starving for some air and that might be a couple miles an hour also.

Mike

[Woodchuckscustoms.com]

Mike

Don't worry about the tack, that will just make ya let off at at red line:bigcry: Just run it till it don't go no faster:hot:

On the rear sprocket have a custom made one that has double plus two teeth then the drive sprocket that should give ya some speed but you will have to use low gear to get r going but should fly with this set up.

So hav a nother 2 or 6 Beers:lush: and re-think the tack idea:cheers:

[Terry Skinner]

[QUOTE=Mike Bean]
The fastest I could get the BSR to run was 44.1 MPH. I know BSR's with rider are not the most aero dynamic rides around, but I expected at least 50 MPH.

Have you considered that the speed indicated on the GPS is just an average over a period of time. I have used the GPS in my motor home and it always lags behind the speedo. I used an electronic speedo from a bicycle on my trike and it works great. You can duct tape it to the frame and 5 min. epoxy the magnet to the wheel. A little calculating and you will know exactly how fast you are going. Just a thought........Terry

[elvergon]

Man why didn´t you took some video of it?

Please we need vids =) Put your wife shooting at you, and don´t roll over her now ;)

Wut about the hubs that are welded to the sprocket?

Those are cheaper here in Mexico than getting a hub and getting a sprocket.
Might wanna check those out.

About 125 83.....ok today they´ll get up to 8,000 easily, However that engine didn´t go into a ATV, I think that ATV´s hold less RPM´s. Does 5,000 sound nice?

[minidragbike]

If you want to go faster, just add some bolt on's. I'm new to the site, and find this a very fun hobby.

I don't own a BSR yet. I'm into racing minibikes. Boy you guys talk about speed. If I told you you guys the speed me and my buddies go. I probaly won't believe me.

I have some pictures but I don't know how to post them.:wave:

[captjima]

I have clocked mine at 48 mph its a five speed honda 125 cc engine that was wound out in 3rd gear Thats where I ran out of balls........

[Mike Bean]

I have clocked mine at 48 mph its a five speed honda 125 cc engine that was wound out in 3rd gear Thats where I ran out of balls........

Can you tell me what size rear sprocket were you running? And was your engine a 2 or 4 stroke?

Thanks,
Mike

[elvergon]

Hey mike, where are the videos bro?

You´ve been playing too much with your toy not to share it with us =(

[Mike Bean]

Hey mike, where are the videos bro?

You´ve been playing too much with your toy not to share it with us =(

Elvergon,

No vids yet. I had put the bsr on the back burner for a couple of weeks to get caught on on some other stuff. I still need to fab up the wheelie bars and I am thinking about some lights because I have a 12V feed on the engine.

Will try to get some quick vids soon..

Mike

[kkuenemann]

I have used this speed calculator before and is accurate. If you are in 4th gear (1:1) ratio, just plug in the info in blanks. You need to know tire circumfrance, drive sproket tooth count, rear sprocket tooth count, chain pitch (#40 is 0.500", #35 is 0.375") and engine RPM.

Give this link a try:http://www.compgoparts.com/TechnicalResources/SprocketCalculator.asp

:hot: