Poll - How fast does your 125cc go? (Vader / Razkull / etc)

[prismways]

So I'm curious, how fast are people pushing their 125cc motorcycle?

I have the Boom Vader with a Mikuni VM26 carb and cone filter and 125 jet.

I haven't pushed it past 43mph with it hovering around 6K RPM but I am noticing that the whole bike buzzes and vibrates so much, I'm wondering if it will fly apart into a hundred pieces. Is 6K RPM about right for cruising speed in 4th gear?

So when you reply, tell us the following:

Make / Model
carb upgrade?
airbox or cone filter
jet uprade?
Top speed
Max RPM
Does your bike feel like it will tear apart at the top speed?
what's your cruising speed and RPM?

Really interested to hear others' experience.

thanks

[Adjuster]

I don't have the bikes you're listing but I do have a Honda horizontal engine 125cc clone bike. It has a fully automatic transmission. It easily will do 45mph but gets loud and buzzy as you say. I think if it had a standard transmission with the right gearing it would go faster and be much smoother. I believe I am running the PZ19 carb with cone filter and I drilled out the exhaust to open it up some. Drilling out the exhaust made the biggest improvement in power/speed.




/


/



/

[prismways]

thanks for chiming in, that is good to know. Do you know what RPM you're at when doing 45pmh? What do you think your max is?

Originally Posted by Adjuster

I don't have the bikes you're listing but I do have a Honda horizontal engine 125cc clone bike. It has a fully automatic transmission. It easily will do 45mph but gets loud and buzzy as you say. I think if it had a standard transmission with the right gearing it would go faster and be much smoother. I believe I am running the PZ19 carb with cone filter and I drilled out the exhaust to open it up some. Drilling out the exhaust made the biggest improvement in power/speed.
/

[Jrack]

Check out (miami scooter club) on youtube. He really pushes his Vader. He has a stock carb, 90jet, air box mod, 17t sprocket and I think an AR exhaust. He commented his bike got to 63, although I'm sure he's gotten it faster since.

I have the Vader 125..
I have stock carb, pod filter and jets coming in the mail today. I took off the exhaust heat shield, drilled out the exhaust and installed a 16t front sprocket. I've pushed my bike to 7000 hit a max of 56 mph. Plan on ordering a piranha oil cooler kit off amazon later this week. I hope it works.

Make sure you check your front fender, when I got the bike I know I tightened it. Vibrated loose and had to re-tighten it. Mine vibrated so much it was uncomfortable to ride. Riding often or whenever I get the chance, the vibrations have gotten better. Also, my break light is just kind of floating...probably cause for a lot of the vibrating going on.

https://www.amazon.com/Piranha-Compl...oil+cooler+kit

[Skin Mechanic]

Before you guys start throwing numbers around, test your speedo for accuracy. I did speed runs on my bike using 3 different GPS based speedo apps on my cell phone and my bike's speedometer is about 5mph optimistic. The speedo would read 59mph and I was really doing 54mph.

[prismways]

Point taken. I'm not looking for anything scientific. Wondering what is the real "red line" on these things and how close I am to it. At 6KRPM and I'm only doing about 45MPH, is it safe to go to 8KRPM to get to a decent cruising speed without killing the motor?

Originally Posted by Skin Mechanic

Before you guys start throwing numbers around, test your speedo for accuracy. I did speed runs on my bike using 3 different GPS based speedo apps on my cell phone and my bike's speedometer is about 5mph optimistic. The speedo would read 59mph and I was really doing 54mph.

[Jrack]

Originally Posted by Skin Mechanic

Before you guys start throwing numbers around, test your speedo for accuracy. I did speed runs on my bike using 3 different GPS based speedo apps on my cell phone and my bike's speedometer is about 5mph optimistic. The speedo would read 59mph and I was really doing 54mph.

This is true. I've had to use a speedo app for my bike before I got a new sensor hub.. 1000 bikes 1000 variations

[jsumd]

Completely stock vader about 48ish

[Skin Mechanic]

When I took my bike on it's first ride I hit 60mph in a full tuck going down a small hill. A bone stock ankle nipper doing 60mph I knew I had to get out the cell phone and do a reality check. I've gotten the bike up to 56mph in a full tuck, on a level straight. The bike was doing 8200rpms with the 15t sprocket. I put a 108 link chain on it yesterday and installed a 16t sprocket. I was able to get up to 56mph@7100rpms on the way home from work today. I've gotta 17t sprocket on order, which will get me up to cruising speed at an even lower rpm, but I'm thinking 16t may be the best compromise between top end speed and off the line acceleration. With the 15t sprocket 1st gear was useless, I would start off in 2nd and give it a little more throttle before letting out the clutch. I can use 1st gear with the 16t sprocket, but under 30mph the acceleration is

[prismways]

That's interesting! I'm going to install the 16T sprocket. I agree, 1st gear right now is so useless on the 15T sprocket. I am willing to give up a little low end acceleration to have a lower RPMs at the high end cruising speed.

My bike is really starting to ride great and every time I take it out, it seems to get smoother. Today I was up to 50mph at around 7000RPM.

Originally Posted by Skin Mechanic

When I took my bike on it's first ride I hit 60mph in a full tuck going down a small hill. A bone stock ankle nipper doing 60mph I knew I had to get out the cell phone and do a reality check. I've gotten the bike up to 56mph in a full tuck, on a level straight. The bike was doing 8200rpms with the 15t sprocket. I put a 108 link chain on it yesterday and installed a 16t sprocket. I was able to get up to 56mph@7100rpms on the way home from work today. I've gotta 17t sprocket on order, which will get me up to cruising speed at an even lower rpm, but I'm thinking 16t may be the best compromise between top end speed and off the line acceleration. With the 15t sprocket 1st gear was useless, I would start off in 2nd and give it a little more throttle before letting out the clutch. I can use 1st gear with the 16t sprocket, but under 30mph the acceleration is

[Skin Mechanic]

Do any of yous guys have registration marks on your chain adjusters? Mine doesn't have them and I couldn't find my alignment tool. I had to use a machinist's rule to get the new chain in the ballpark until the new alignment tool arrived this morning.

[bogieboy]

i had a 110cc horizontal pocket bike that i hit 57 mph with... but that took some work...LOL stage 2 cam, vm26 carb, ported head, and a wide open exhaust.... was a wicked bike though...LOL

[prismways]

Nope, no markings whatsoever. Before I change my sprockets, I'm going to put in some markings on both sides.

Originally Posted by Skin Mechanic

Do any of yous guys have registration marks on your chain adjusters? Mine doesn't have them and I couldn't find my alignment tool. I had to use a machinist's rule to get the new chain in the ballpark until the new alignment tool arrived this morning.

[PhildoScaggins]

Originally Posted by Skin Mechanic

Do any of yous guys have registration marks on your chain adjusters? Mine doesn't have them and I couldn't find my alignment tool. I had to use a machinist's rule to get the new chain in the ballpark until the new alignment tool arrived this morning.

I've just kinda eyeballed it... not the best idea but I have only hit 50 miles as of today. Still waiting on my MCO. Wondering if scratching or putting light markings in with a grinder is a bad idea or not.

[prismways]

hehe. yeah, the grinder might be overkill. I was thinking of a file or flathead screwdriver. lol.

Originally Posted by PhildoScaggins

I've just kinda eyeballed it... not the best idea but I have only hit 50 miles as of today. Still waiting on my MCO. Wondering if scratching or putting light markings in with a grinder is a bad idea or not.