Go Back   DIY Go Kart Forum > Building Plans And Advice > Engines & Clutches

Notices

Closed Thread
 
Thread Tools Display Modes
  #41  
Old 01-16-2011, 07:31 PM
slideways slideways is offline
Senior Member
 
Join Date: Nov 2008
Posts: 575
Thanks: 0
Thanked 77 Times in 74 Posts
Default

I saw earlier someone posted the carb throat measurement. That is not the correct measurement for the venturi portion. It is right around .615. Afterwards it may be larger but it is not 19mm since those carbs are an upgrade for a hotter build setup.
  #42  
Old 01-16-2011, 07:58 PM
Doc Sprocket's Avatar
Doc Sprocket Doc Sprocket is offline
*********
 
Join Date: Jun 2009
Location: Ontario, Canada
Posts: 15,677
Thanks: 723
Thanked 2,205 Times in 1,693 Posts
Default

I measured at the mating surface. I don't have a caliper that will reach deep enough to measure the venturi area.
__________________
Treat it as you would an aircraft frame and you should have no problems. -Name Withheld
The Manual- "Just the manufacturer's opinion of how to put this together."- Tim "The Tool Man" Taylor
Put down the wrench, and come out with your hands up!- Me!
Wrench, Wheel, Wreck, Repeat...
  #43  
Old 01-17-2011, 09:48 PM
slideways slideways is offline
Senior Member
 
Join Date: Nov 2008
Posts: 575
Thanks: 0
Thanked 77 Times in 74 Posts
Default

Ah ok. I get most of my clone info from the kart racing boards. They stock classes have a very strict gauge that cant pass through the venturi and that's the measurement they have to be under. Trick to power is getting it right there but no more since the carbs on clones have alot of variances.
  #44  
Old 01-25-2011, 07:19 AM
bgtcars bgtcars is offline
Junior Member
 
Join Date: Oct 2010
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Default

the plug in the pilot adj hole is to keep from adjusting carb like old ones . epa's idea less emissions US is only place used. sediment bowl stops big stuff and water/condensation from getting into float bowl, just a good pre filter
  #45  
Old 01-25-2011, 12:42 PM
devino246's Avatar
devino246 devino246 is offline
Official DIYGK Chem Nerd
 
Join Date: Sep 2009
Location: Lynchburg, VA
Posts: 3,856
Thanks: 270
Thanked 284 Times in 245 Posts
Default

Quote:
Originally Posted by bgtcars View Post
the plug in the pilot adj hole is to keep from adjusting carb like old ones . epa's idea less emissions US is only place used. sediment bowl stops big stuff and water/condensation from getting into float bowl, just a good pre filter
I believe we had already figured that out.

@toystory, any progress?
__________________
ASE Certified
  #46  
Old 01-25-2011, 03:50 PM
808moparskate 808moparskate is offline
Junior Member
 
Join Date: Jan 2011
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I was on the internet last night finding mods for myself and came a acrooss a websaite called affordable go karts and they have everything on how to remove govener and all the basic mods. I wanna do a semi mod motor for my go kart and i put a package together that costs 180 dollars this includes a metal cam with higer lift on the exhaust and intake and longer duration (no more plastic cam) this also includes an aluminum flywheel so i dont have shrapnel in my back also some odds and ends like 18pound valve springs tehn differant mods you can do for free but my kit also included an 8 degree timing key with a bunch of stuff and you got a pretty good motor i must say.
  #47  
Old 01-25-2011, 03:57 PM
r_chez_08's Avatar
r_chez_08 r_chez_08 is offline
Should be in the shop...
 
Join Date: Jan 2009
Location: Cornwall, UK
Posts: 4,827
Thanks: 182
Thanked 313 Times in 308 Posts
Default

The stock camshaft on these motors is not plastic?
__________________
My process of thought:
Anyone can drive a fast car, few can drive a car fast.
  #48  
Old 01-25-2011, 04:45 PM
devino246's Avatar
devino246 devino246 is offline
Official DIYGK Chem Nerd
 
Join Date: Sep 2009
Location: Lynchburg, VA
Posts: 3,856
Thanks: 270
Thanked 284 Times in 245 Posts
Default

Quote:
Originally Posted by 808moparskate View Post
I was on the internet last night finding mods for myself and came a acrooss a websaite called affordable go karts and they have everything on how to remove govener and all the basic mods. I wanna do a semi mod motor for my go kart and i put a package together that costs 180 dollars this includes a metal cam with higer lift on the exhaust and intake and longer duration (no more plastic cam) this also includes an aluminum flywheel so i dont have shrapnel in my back also some odds and ends like 18pound valve springs tehn differant mods you can do for free but my kit also included an 8 degree timing key with a bunch of stuff and you got a pretty good motor i must say.
First, as stated several times by several people, the stock flywheel WILL NOT explode unless the flywheel has been tampered with. Its a myth. Second, the stock cam on Hondas or clones arent plastic. Third, if your removing the governor and doing all this other stuff, you really need to replace the stock connecting rod with a billet one. Theres a decent chance of the stock rod breaking and destroying your engine.

I modded my clone with the following:
Billet connecting rod
Removed governor
18lb valve springs
Port and polish head
High flow air filter
High flow DIY exhaust
(will be rejetting carb this week)

Spent like $120. BTW, before doing anything, make sure you've read up on your 4 stroke engine theory.
__________________
ASE Certified
  #49  
Old 01-25-2011, 06:22 PM
Doc Sprocket's Avatar
Doc Sprocket Doc Sprocket is offline
*********
 
Join Date: Jun 2009
Location: Ontario, Canada
Posts: 15,677
Thanks: 723
Thanked 2,205 Times in 1,693 Posts
Default

Ahh, in no particular order-

@bgtcars- we do already have all that stuff nailed down- thanks.
@Devino- No real progress lately. I've been busy with several things, and will not be doing much else with the engine until I get my gasket set in.
@808mopar AND Rchez- Plastic camshaft? No. A plastic camshaft wouldn't survive 30 seconds. The gear is plastic, though. Presumably to reduce noise/friction.
I have no worries about that. I've seen plastic gears/sprockets in use in engines many times in the past, with no failures.
__________________
Treat it as you would an aircraft frame and you should have no problems. -Name Withheld
The Manual- "Just the manufacturer's opinion of how to put this together."- Tim "The Tool Man" Taylor
Put down the wrench, and come out with your hands up!- Me!
Wrench, Wheel, Wreck, Repeat...
  #50  
Old 01-26-2011, 02:31 AM
r_chez_08's Avatar
r_chez_08 r_chez_08 is offline
Should be in the shop...
 
Join Date: Jan 2009
Location: Cornwall, UK
Posts: 4,827
Thanks: 182
Thanked 313 Times in 308 Posts
Default

Yeah I knew it wasn't plastic cos I had the sidecover off my clone to remove the gov. I was just questioning 808mopar.
__________________
My process of thought:
Anyone can drive a fast car, few can drive a car fast.
  #51  
Old 01-26-2011, 04:55 AM
dan's Avatar
dan dan is offline
Senior Member
 
Join Date: Feb 2009
Location: Austraila
Posts: 330
Thanks: 0
Thanked 4 Times in 4 Posts
Default

Quote:
Originally Posted by devino246 View Post
I modded my clone with the following:
Billet connecting rod
Removed governor
18lb valve springs
Port and polish head
High flow air filter
High flow DIY exhaust
(will be rejetting carb this week)

Spent like $120. BTW, before doing anything, make sure you've read up on your 4 stroke engine theory.
so obviously u have not done ur reading on 4 stoke engines as u would know that polishing the head makes it not flow as well. as wen the rough finish is in the port the air molecules get stuck in the little rough tooling marks or pitting sort of thing. the air then goes into a swirl in these making the air coming in to the intake flow faster. As the air coming in WILL flow faster across the swirling air then it will on the polished part.

thanks for taking the time to read this. cheers, Dan
__________________
Alcohol: is for drinking. fuel: is for washing parts in. nitromethane: is for running engines on.
  #52  
Old 01-26-2011, 08:00 AM
newrider3's Avatar
newrider3 newrider3 is offline
Senior Member
 
Join Date: Aug 2007
Location: Colorado
Posts: 1,674
Thanks: 58
Thanked 124 Times in 95 Posts
Default

Quote:
Originally Posted by dan View Post
so obviously u have not done ur reading on 4 stoke engines as u would know that polishing the head makes it not flow as well. as wen the rough finish is in the port the air molecules get stuck in the little rough tooling marks or pitting sort of thing. the air then goes into a swirl in these making the air coming in to the intake flow faster. As the air coming in WILL flow faster across the swirling air then it will on the polished part.

thanks for taking the time to read this. cheers, Dan
Port and polish is just a general term. Most of the time you will port both the intake and exhaust (to remove casting imperfections) and only polish the exhaust port. By leaving the intake slightly rough it doesn't increase flow, it helps the mixture stay atomized.
  #53  
Old 01-26-2011, 08:22 AM
robbie robbie is offline
Senior Member
 
Join Date: Apr 2010
Location: Osceola, Missouri
Posts: 857
Thanks: 9
Thanked 76 Times in 56 Posts
Default

Air will flow with less drag over a rough surface than a smooth one. In airplanes they call this "laminar flow".

If you have a smooth surface, the air drags against it.

A rough surface traps a layer of air, and the main body of air drags against the small air layer.
  #54  
Old 01-26-2011, 01:27 PM
devino246's Avatar
devino246 devino246 is offline
Official DIYGK Chem Nerd
 
Join Date: Sep 2009
Location: Lynchburg, VA
Posts: 3,856
Thanks: 270
Thanked 284 Times in 245 Posts
Default

Quote:
Originally Posted by newrider3 View Post
Port and polish is just a general term. Most of the time you will port both the intake and exhaust (to remove casting imperfections) and only polish the exhaust port. By leaving the intake slightly rough it doesn't increase flow, it helps the mixture stay atomized.
Yep. Exactly what I did.
__________________
ASE Certified
  #55  
Old 01-26-2011, 06:05 PM
Doc Sprocket's Avatar
Doc Sprocket Doc Sprocket is offline
*********
 
Join Date: Jun 2009
Location: Ontario, Canada
Posts: 15,677
Thanks: 723
Thanked 2,205 Times in 1,693 Posts
Default

That's very interesting. I have heard the same is true for boat hulls, being that a very slightly (near-microscopic) rough texture will make for a faster hull because the water will slightly adhere to an ultra-smooth surface.
__________________
Treat it as you would an aircraft frame and you should have no problems. -Name Withheld
The Manual- "Just the manufacturer's opinion of how to put this together."- Tim "The Tool Man" Taylor
Put down the wrench, and come out with your hands up!- Me!
Wrench, Wheel, Wreck, Repeat...
  #56  
Old 01-26-2011, 06:55 PM
robbie robbie is offline
Senior Member
 
Join Date: Apr 2010
Location: Osceola, Missouri
Posts: 857
Thanks: 9
Thanked 76 Times in 56 Posts
Default

Quote:
Originally Posted by toystory_4wd View Post
That's very interesting. I have heard the same is true for boat hulls, being that a very slightly (near-microscopic) rough texture will make for a faster hull because the water will slightly adhere to an ultra-smooth surface.
Yeah, that's a word I forgot to include. Near-microscopic. These surfaces are rough like 220 grit sand paper.
  #57  
Old 01-31-2011, 05:19 PM
808moparskate 808moparskate is offline
Junior Member
 
Join Date: Jan 2011
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by r_chez_08 View Post
The stock camshaft on these motors is not plastic?
the gear is and so are the lobes but they are formed onto a metal rod if thats what you mean?
  #58  
Old 01-31-2011, 05:56 PM
Doc Sprocket's Avatar
Doc Sprocket Doc Sprocket is offline
*********
 
Join Date: Jun 2009
Location: Ontario, Canada
Posts: 15,677
Thanks: 723
Thanked 2,205 Times in 1,693 Posts
Default

The lobes are NOT plastic. Please re-read post #49.
__________________
Treat it as you would an aircraft frame and you should have no problems. -Name Withheld
The Manual- "Just the manufacturer's opinion of how to put this together."- Tim "The Tool Man" Taylor
Put down the wrench, and come out with your hands up!- Me!
Wrench, Wheel, Wreck, Repeat...
  #59  
Old 01-31-2011, 07:43 PM
newrider3's Avatar
newrider3 newrider3 is offline
Senior Member
 
Join Date: Aug 2007
Location: Colorado
Posts: 1,674
Thanks: 58
Thanked 124 Times in 95 Posts
Default

Quote:
Originally Posted by toystory_4wd View Post
Plastic camshaft? No. A plastic camshaft wouldn't survive 30 seconds. .
They may not be comparable in durability to an average iron cam, but they do exist. Tecumseh OHH-series kart motors, and Briggs Quantum flathead vertical motors are two that come to mind, that I have personally taken apart. The lobes are indeed plastic.
/threadjack
  #60  
Old 01-31-2011, 07:55 PM
jareeB jareeB is offline
Senior Member
 
Join Date: Aug 2010
Posts: 164
Thanks: 1
Thanked 7 Times in 7 Posts
Default

toy story you will need a billet rod the is the weak point, if the motor turns over 4k you will break the rod, just spend 60 bucks and get a billet rod also i would by a flat top piston well you at it.

rod

flat top

also the rings that came with the motor can be used, but if you used the engine before to break it in, then i wouldn't risk using the piston wist pin clips again. i have built my modded clone still have to start it and people over a oldminibike.com said that the billet rod is mandatory
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 05:47 PM.