4-stroke performance

Josh_wilcoxx

Active Member
Local time
9:25 PM
Joined
Jun 4, 2019
Messages
123
Hey guys! As you may have seen I built a 4 stroke for my girl to cruise around on, and as you could imagine, it's a bit slow. With a lot of pedaling help and about a half mile, it holds about 25mph flat. Is there a certain website I can buy actual performance mods on? Is there a way to tweak valves/carb on this motor to get more power? What clutch should I get? I know you don't get these to haul ass on, but I would like it to be a BIT quicker.
 

Attachments

  • IMG_20220522_201045.jpg
    IMG_20220522_201045.jpg
    279.1 KB · Views: 101

darwin

Well-Known Member
Local time
10:25 PM
Joined
May 26, 2008
Messages
5,799
Do you have a pic of the left side? Don't see what kind of tranny is being used. That rear sprocket looks huge, same as 1st gear on a bicycle 21sp which is geared for torque and not top end.
 

DieselTech

Well-Known Member
Local time
11:25 PM
Joined
Sep 18, 2021
Messages
4,741
Hey guys! As you may have seen I built a 4 stroke for my girl to cruise around on, and as you could imagine, it's a bit slow. With a lot of pedaling help and about a half mile, it holds about 25mph flat. Is there a certain website I can buy actual performance mods on? Is there a way to tweak valves/carb on this motor to get more power? What clutch should I get? I know you don't get these to haul ass on, but I would like it to be a BIT quicker.
Yeah as Darwin mentioned! What tranny/gearbox are you using? To me by pic it looks like possibly you are just using some type of centrifugal clutch. I'm using a grubee 5:1 trans with 9/36 gearing & I can get 28-32mph out of mine. It's been modded thou. 7/8id straight pipe about 28-30" long & a dellorto 15:15 carburetor.
 

Josh_wilcoxx

Active Member
Local time
9:25 PM
Joined
Jun 4, 2019
Messages
123
Do you have a pic of the left side? Don't see what kind of tranny is being used. That rear sprocket looks huge, same as 1st gear on a bicycle 21sp which is geared for torque and not top end.
I don't at the moment, it's just a basic stock transmission from the eBay special engine.
 

Mike St

Well-Known Member
Local time
10:25 PM
Joined
Jun 16, 2008
Messages
757
You can follow my updates on improving the carb performance that
comes with the kit, and using the flexible 7/8 inch exhaust, 28.5
inches long for a proven (on a dyno) 18% increase in power. You
need to adjust the sprocket ratio for more top speed.
 

Josh_wilcoxx

Active Member
Local time
9:25 PM
Joined
Jun 4, 2019
Messages
123
You can follow my updates on improving the carb performance that
comes with the kit, and using the flexible 7/8 inch exhaust, 28.5
inches long for a proven (on a dyno) 18% increase in power. You
need to adjust the sprocket ratio for more top speed.
Sounds good I'll look into it! Also, the sprocket is big (for now) so it's possible to get to a decent speed in a okay amount of time. Still not much torque being transferred from the engine.
 

Mike St

Well-Known Member
Local time
10:25 PM
Joined
Jun 16, 2008
Messages
757
If you give more details about your belt drive and sprocket
choices we can calculate a top speed for you, and suggest
what would meet your needs. You have to be more
specific, supply more details.
 

Sidewinder Jerry

Well-Known Member
Local time
12:25 AM
Joined
Mar 14, 2011
Messages
4,076
Location
Rockwood, TN
You can follow my updates on improving the carb performance that
comes with the kit, and using the flexible 7/8 inch exhaust, 28.5
inches long for a proven (on a dyno) 18% increase in power. You
need to adjust the sprocket ratio for more top speed.
The problem here is your profile settings. Permission is needed to access your former threads and postings. You could actually post a link of the thread you're talking about. Here I'm going to assume you're talking about this thread:

 
Top