top speed calculators

#4
i came across one, but with my current security settings (locked down, it's a PITA at times to view some sites) it wouldn't allow me to access the site.
 

minidragbike

Supporting Speed Nut!
#7
Yes, this makes things a little more accurate. I didn't like having to re-post the same stuff over and over. Now we just need these guys to buy Tach's for there bikes.
 
#10
I always wondered why mine hauls ass top end for a little 3.5HP with intake/exhaust mods. I have a 40 tooth rear sprocket and a 13 tooth clutch sprocket.. GEEZ. I need to do some gearing changes because it's a slug off the line, but I am 6' 240lbs as well.

I have no clue what RPM I am going though...
 
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minidragbike

Supporting Speed Nut!
#11
I always wondered why mine hauls ass top end for a little 3.5HP with intake/exhaust mods. I have a 40 tooth rear sprocket and a 13 tooth clutch sprocket.. GEEZ. I need to do some gearing changes because it's a slug off the line, but I am 6' 240lbs as well.

I have no clue what RPM I am going though...
You gotta save you money and get a bigger engine first. Then get a tach and see what your doing.
 
#12
You gotta save you money and get a bigger engine first. Then get a tach and see what your doing.
It's in the works. I'm picking up a lot of 2 3.5's, 1 2 1/2, and 2 5HP flats along with a bunch of parts like carbs,clutches etc etc.. Bunch-0-briggs-stuff.. all for $20.

I will try my first flathead briggs build. I know NOTHING about small engines at all lol. I just rebuilt my first carburetor for my 3.5 and it runs fantastic now.

I'll order a tach up when I start the build. I have to find a frame I can use for the bigger engine. The CAT is too small.
 

cxbra

New Member
#13
I always wondered why mine hauls ass top end for a little 3.5HP with intake/exhaust mods. I have a 40 tooth rear sprocket and a 13 tooth clutch sprocket.. GEEZ. I need to do some gearing changes because it's a slug off the line, but I am 6' 240lbs as well.

I have no clue what RPM I am going though...
Thats wild, your geared to do like 35-40 at 3600rpm probably. You would notice a huge difference switching to a 60 tooth rear sprocket from the 40. Im runnin 12/60 w/ a 12" tire on my Bonanza, un-governed 5hp Briggs, header and intake. Lets just say, this thing boogies :scooter:
 
#14
Thats wild, your geared to do like 35-40 at 3600rpm probably. You would notice a huge difference switching to a 60 tooth rear sprocket from the 40. Im runnin 12/60 w/ a 12" tire on my Bonanza, un-governed 5hp Briggs, header and intake. Lets just say, this thing boogies :scooter:
At 5000rpms you would be going a little more than 35mph, it's possible you could turn more rpms but doubtfull unless you have more mods to your 5hp engine.............Without a tire size it would be nearly impossible to figure rarecrx's top speed though but say he's rollin on 13s and ever gets to 4500 he'd be doing 57mph but being a bigger guy he'd need a long stretch of road to get there!
 
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Clyde

New Member
#19
Another Jack-shaft gear ratio with tire size calculator = Rawge's Mini Chopper Information Site - Jackshafts

Tachometers?
GO TO ebay, or Amazon.com ... type in "tachometer hour meter" in their search. For about $15 USD there are cheap induction models flooding the market now (12/2010). They need NO other wiring hook-up (or power supply) other than its own single wirewrap to your spark plug.

A single wire from tach wraps 3-4 times around the spark plug wire and senses the electrical pulse. It will work on many 2 stroke and 4 strokes (it's programmable per how many spark plug firings per revolution). Has an Hour Meter on it too.
Cheap, and Chinese, it will only last as long as it's lithium battery works (they say about 4 years, probably less)
They look like this EXAMPLE:

This is just an example I pulled from some Amazon sellers page Amazon.com: Digital Hour Meter and Tachometer with Maintenance Settings: Automotive
 
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