Need help with First build - Roughhouse 50

[thedude13]

Hi everyone, this is my first post as I am VERY new to the scooter community. I am hoping to get any and all information possible for my first build.

I have a completely stock 2 stroke Roughhouse 50. I did some initial research to see the capabilities of this scooter and it seems promising.

My plan to is do the below mods:
Wedding ring de-restrict
Malossi 70cc kit
DellOrto 21mm carb
New exhaust pipe
Molassi multivar cvt

The goal is to have a top end speed of 60-70mph (please tell me if I’m crazy for that).

Questions I have:
What size jets would I need for the 21mm carb? Do I need any additional parts?
What is the best exhaust for this set up? Do I need any different mounting brackets or anything?
Does the multivar kit come with the correct weights? If not, what weights should I use?

Any additional information or recommendations would be very helpful. Thanks in advance!

[k1v]

well first of all about the pipe, depends what malossi cylinder, since u didnt mention a crank upgrade im assuming the malossi sport, for this cylinder u can mostly get any sport pipe like yasuni r and similar sport pipes, up to yasuni c16, the stock main jet for the carb will work for the start, noone can tell u the exact size of jets u have to use because it always depends on many factors. If the mixture is too rich u should down jet since i dont think the stock jet will be running lean.  About the weight its again all tuning. Depending of what clutch springs u have installed u should aim for +- 10k rpm at max throtlle. The top speed will be about 60 if u tune everything right, not doing 70mph tho..

[thedude13]

thanks for the response. after some discussions i had, i think this will be my setup. what are your thoughts?

Polini sport 70cc kit
DellOrto 17.5mm carb
Main Jet Set Stage6 Dellorto 6mm
Yasuni R
Molassi multivar cvt / blue clutch springs
stage6 vented bell

[Zino]

Polini sport and Yasuni R is a great combo
I used red Malossi springs to get up in the power band of that pipe .

[k1v]

Apr 18, 2024 15:25:25 GMT -5 thedude13 said:

thanks for the response. after some discussions i had, i think this will be my setup. what are your thoughts?

Polini sport 70cc kit
DellOrto 17.5mm carb
Main Jet Set Stage6 Dellorto 6mm
Yasuni R
Molassi multivar cvt / blue clutch springs
stage6 vented bell

sounds okay but id say get a new clutch like the polini 3g not clutch bell since they should be pretty similar in price, also i would go for a 21mm carb if you want to upgrade and id go for the s6 streetrace instead of polini but thats just my preference.

[thedude13]

Good info about the clutch. I guess I could get both. as for the carb, I've heard that a 21mm carb will work but you lose acceleration and throttle response and that a larger carb will tend to rev out higher. Without adding a new crank you'd want to limit rpm. 

Is that accurate? I definitely don't want to mess with the crank.

[k1v]

Apr 19, 2024 6:32:30 GMT -5 thedude13 said:

Good info about the clutch. I guess I could get both. as for the carb, I've heard that a 21mm carb will work but you lose acceleration and throttle response and that a larger carb will tend to rev out higher. Without adding a new crank you'd want to limit rpm. 

Is that accurate? I definitely don't want to mess with the crank.

stock crank will be fine AS long as its in good condition, same as the bearings, i mean if the crank doesnt have any up and down play or u know that it is fresh id say send it, the rpm is not limited by the carb, so id still suggest going with a bigger carb for 70cc if you have the money. what does change rpm is the transmission tuning, the roller weight, and all of the clutch springs all affect the rpm, for sport cylinders as i said u should aim for about 10k since thats about where the peak power is. Limiting the rpm really under that would just be a waste of power. U should just install the exhaust and all new parts and after it has been run in start with the tuning of carb, then trans.

[thedude13]

Apr 19, 2024 7:36:27 GMT -5 k1v said:

Apr 19, 2024 6:32:30 GMT -5 thedude13 said:

Good info about the clutch. I guess I could get both. as for the carb, I've heard that a 21mm carb will work but you lose acceleration and throttle response and that a larger carb will tend to rev out higher. Without adding a new crank you'd want to limit rpm. 

Is that accurate? I definitely don't want to mess with the crank.

stock crank will be fine AS long as its in good condition, same as the bearings, i mean if the crank doesnt have any up and down play or u know that it is fresh id say send it, the rpm is not limited by the carb, so id still suggest going with a bigger carb for 70cc if you have the money. what does change rpm is the transmission tuning, the roller weight, and all of the clutch springs all affect the rpm, for sport cylinders as i said u should aim for about 10k since thats about where the peak power is. Limiting the rpm really under that would just be a waste of power. U should just install the exhaust and all new parts and after it has been run in start with the tuning of carb, then trans.

my Roughhouse is a 2022 with roughly 1200 miles. is it true that the bigger carb will lose throttle response? I am really just looking for a solid build that has reliability and quick acceleration and a good top end speed. 

[Zino]

Yes bigger carbs have less throttle response .
a 17.5 is plenty big enough for your sport level build.
and you still can use the stock throttle cable .

[aeroxbud]

And using a 17.5mm carb. It should fit into the standard air box no problem.