hi tq setup for go kart idea?

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garredondojr

New Member
#1
#1
Been hoarding some parts for my kids off road go kart. Its a yerf dog 2 seater. I'm more resourceful than rich and also plan to keep the governor intact for speed/safety reasons.
Here's what I have and my plan. Please critique it.
Gx200 clone
Flat top gx160 piston and Honda rod
14cc head, unshrouded valves, ssr cleaned up, weld cc heart shaped
Tilloston hl 166b
E85 fuel
Grind base circle on cam as much as possible
Deck block till piston is .015 out of the block
Gx160 headgasket
Gx160 flywheel lapped

Essentially I'm after the most low end power for essentially no additional money spent. Hi compression, hi lift, hi velocity ports, ect. Sound logical?
 
JamnJM

JamnJM

New Member
#2
#2
Why all that if governor still there? A waste IMO.

Honda rod and gx160 flywheel are not billet so little if no benefit on them.
 
Newoldstock

Newoldstock

New Member
#3
#3
garredondojr said:
Been hoarding some parts for my kids off road go kart. Its a yerf dog 2 seater. I'm more resourceful than rich and also plan to keep the governor intact for speed/safety reasons.
Here's what I have and my plan. Please critique it.
Gx200 clone
Flat top gx160 piston and Honda rod
14cc head, unshrouded valves, ssr cleaned up, weld cc heart shaped
Tilloston hl 166b
E85 fuel
Grind base circle on cam as much as possible
Deck block till piston is .015 out of the block
Gx160 headgasket
Gx160 flywheel lapped

Essentially I'm after the most low end power for essentially no additional money spent. Hi compression, hi lift, hi velocity ports, ect. Sound logical?
Click to expand...
Sounds like you have been reading Oldschool's old posts ( HL 166B is an obscure carb )...
So you think that old coot was on too something with the high compression head piston and small carb or something?

My input.
No to the welded 14cc head just add the valve train upgrade.

No to the high lift cam or any modification to a stock one ( the latter will not work anyways ).
Your better off with a CL-2 Mod cam or something inexpensive with limited lift and more duration.

No E85, that carb will not suport it.

Next you need to some billet parts.
 
cheezy1

cheezy1

#4
#4
BILLET ROD!!!...and deck the block to 0 to -.005...and mill head after that so you can check clearance before removing too much off the head. Also with whatever cam you choose also important to check clearances.
 
G

garredondojr

New Member
#5
#5
Interesting responses. Billet parts are out of the picture for me. And I can see the whole why do all that and keep the governor intact responses. My uncle owns a small engine repair shop and I scavenged the bone yard for all the parts. In other words zero out of pocket cost. Its also a challenging/ fun to make something from nothing. I own a tig welder so Dr'ing the head is not a issue. Tempted to weld the port floor and raising the roof some to increase flow yet keep port volume down to keep velocity up. Seems like a waste to some but just trying to get this small block to perform like a big block down low. My only concern is cylinder pressures and the stock rod. Guess its just best to go from the theory dept. And jump into the experimental ave. Forgot to add ill be making a long tube header for it as well.
 
JamnJM

JamnJM

New Member
#6
#6
Honda rods on lawn mowers still break all the time the shops tell me....

Add compression, longer intake manifold tract, small carb, Longer exhaust........and low gears.
 
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Newoldstock

Newoldstock

New Member
#7
#7
You can't run the HL 166B and a governer.

You could stay governed and run the rod, piston, and flywheel.

I am assuming the 22cc head and that will yeild more compression.
AS long as you don't push it the governer can be modified a little to raise the top end a touch say 4500, but don't press you luck

Add a header and some jetting....

More or less this engine is what you are discribing but without trying to modify the cam.
100 9289 - YouTube
It was reliable and made more torque.

Here's that bikes Head a ported and polished 14cc ( the black one )


Here's a 166B in mock up on a GX160


Ask your uncle to keep his eyes open for an old "tin top" Honda GXV 160 mower.
These are the verysion with the push rod engine and it has a metal blower housing.
That engines flywheel will bolt onto the GX200 clone and its near as good as billet.
Now you need only buy a 59 dollar billet rod.

You should use at the bare minimum all Honda vlave train components including push rods
 
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JamnJM

JamnJM

New Member
#8
#8
NOS is that red intake manifold custom made or off what? I'm also playing around with a U shaped intake for a Mikuni carb with filter ram air intake. :thumbsup:
 
Newoldstock

Newoldstock

New Member
#9
#9
JamnJM said:
NOS is that red intake manifold custom made or off what? I'm also playing around with a U shaped intake for a Mikuni carb with filter ram air intake. :thumbsup:
Click to expand...
Yes it was custom.
In its final form it did have a velocity stack and....
I need to look for a picture of it.


<a href="http://s426.photobucket.com/albums/pp344/Dougwp/clone%20stuff/?action=view&amp;current=100_9771.jpg" target="_blank"><img src="http://i426.photobucket.com/albums/pp344/Dougwp/clone%20stuff/th_100_9771.jpg" border="0" alt="Photobucket" ></a>

<a href="http://s426.photobucket.com/albums/pp344/Dougwp/clone%20stuff/?action=view&amp;current=100_9771.jpg" target="_blank"><img src="http://i426.photobucket.com/albums/pp344/Dougwp/clone%20stuff/th_100_9771.jpg" border="0" alt="Photobucket" ></a>[/I


Never going to get this linking buisness fingered out

[URL=http://s426.photobucket.com/albums/pp344/Dougwp/clone%20stuff/?action=view&current=100_9771.jpg][IMG]http://i426.photobucket.com/albums/pp344/Dougwp/clone%20stuff/th_100_9771.jpg[/URL]

Hurray IT WORKED.

Thanks Tom...

Now for the rest of "making a yerdog husle "
Replace the Comet green with a Yellow spring in the secodanry clutch.
Change to a 9 tooth drive sprocket ( what you loose on top end in ratio you will get back from an engine that winds up to 4500 rpm or more ).

Other engine stuff:
You need a header and free flowing air filter what is up to you.
If you find some nice thin wall pipe in the 3/4 to 7/8 range inside that is a very good start for a header.
Longer is better and the Dog offers you plenty of room to get to 25 inches just be sure to brace it and put the largest mufler within reason you can on the end.
Somethiong off and ATV would probably work fine.

Does not tak emuch to make a YerfDog into a much better machine.
They were a fine kart from the get go but theyt chose some rotton springs in the clutch and the ratio was chosen to keep rpm down and it makes it tottaly impractical for the little bugger to climb anything as built.
 
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novaracer

novaracer

New Member
#10
#10
nr racing 274 marine grind if you want a tq monster:thumbsup: if it do go it will break somthing in the drive train. its strong and flat tq cruve is on the violent side:doah:
 
Newoldstock

Newoldstock

New Member
#11
#11
novaracer said:
nr racing 274 marine grind if you want a tq monster:thumbsup: if it do go it will break somthing in the drive train. its strong and flat tq cruve is on the violent side:doah:
Click to expand...
I want you to think for a minut now.
274 lift and 260 duration.
3500 to 7500 RPM
That's too much.
And its not needed for what he is asking ( not including the cost )

HE states
" Essentially I'm after the most low end power for essentially no additional money spent. "

At the risk of sounding arogant I already made a sugestion that will do what he asked for.
His kids are going to be riding it not trying to race it.
 
TomH

TomH

New Member
#12
#12
Good to see you getting the hang of it posting pictures NOS. Have you noticed, I'm sure you have, that when a poster in the motor section asks for just a bit more power or more torque, doesn't want to spend a bunch of money...$5000 dollars later.:laugh: Motor heads are like that I suppose, it always gets out of hand. 70 mile an hour wheel standing yerf dog go cart for a 9 year old.:laugh:
 
Newoldstock

Newoldstock

New Member
#13
#13
This new guy has Yerfdog.
Probably a 3203.

I know that machine because half my minibike is made out of driveline components from it.

His kids have been driving it and already he has noticed it does not climb worth a dam.
Yerf realy dropped the ball on that because they made a machine that was more of a drt road flat surface machine.
Its heavy and the clutch is not set up to climb.
The OEM Tec engine is a real dog too.

So tighten up the clutch and tweak the gearing and it will climb, but you slow it down a little....

To compensate you need an engine that has more opperating RPM and aboput 1000 rpm more is all you need to get back to where it was for top speed.

Now a bit more low end torque can still be easily squeezed out of the clone with some compression and freerer breathing.

Can't get stupid though...
Kids are going to be driving it so it needs to be well mannered and predictable with a truely flat torque curve.

Now if he needs a cam just by looking at the numbers you can see a 230 - Torquer or 252-02 is probably better because it does not have stupidly high lift so no block modifications are required and both can use a light 18 pound spring.

This is important in yard kart where its going to rack up some hours.
High spring rates are tough on the valve train.

Lets get back to compression.
10:1 is the biggest single leap you can make with the most pay back.
Everything after that is a deminishing return and it gets real hard on the engine.

Add a little timing say 4 deg ( not too much because that will kill your bottom end )

There you go an example of a simple little build for an all billet motor.
But this guy did not ask for that.

Realy just the 14cc head on that engine with the governer tweaked and some jetting, free flow exahust coupled with the clutch modification I sugested will do what he wants.

BUT he said Kids....
Ah kids...

Do you realy want kids riding on a mildly soupled up kart with out an upgraded rod and flwheel?
Probably not.

I sugeste the GXV flywheel because there is agood chance he can score one for free.
But given a real choice in the matter I would order an ARC steel billet flywheel

I like that because its heavy.
Heavy will dampen out the torque pulses at low speed and moderate how quick the engine excellerates if the rear end breaks loose.

I think he can build this all for 120 for ARC rod and steel flywheel + 14 dollar clutch spring kit, 15 dollar air filter 10 dollar adpator 30 dollar header.....

Less if he can make the header and air filter adaptor himself ( got a wood lathe? make an crude airfilter adaptor out of a block of hard wood and paint it ).

Think small is where its at.....
 
novaracer

novaracer

New Member
#14
#14
Newoldstock said:
I want you to think for a minut now.
274 lift and 260 duration.
3500 to 7500 RPM
That's too much.
And its not needed for what he is asking ( not including the cost )

HE states
" Essentially I'm after the most low end power for essentially no additional money spent. "

At the risk of sounding arogant I already made a sugestion that will do what he asked for.
His kids are going to be riding it not trying to race it.
Click to expand...
I was just saying that cam would be very nice for that app just use 26lb springs and a higher stall clutch spring i feels like a waayy bigger motor from idle to about 6grand then it starts to fall off a bit. But it is money well spent for a non racing cart. Oh and it sounds nasty!
 
G

garredondojr

New Member
#16
#16
Thanks for the input guys. Totally overlooked the gov linkage and the tilloston looks like the stock carb must stay. The spring upgrades for the clutch sound nice but not sure if the knock off tq converter will accept them. Bought the kart as a roller. No engine or converter. Definitly have a better understanding as to how weak the stock rod must be.
 
Newoldstock

Newoldstock

New Member
#17
#17
First let start by saying I have not used these NR cams.

All I have to look at is the lift and durration numbers.
And from that I can see durrations around 230 and thats good for a motor you want low speed performance out of.

But they fall flat sooner than racier grinds.
Thats OK his kids will never spin it above 5000 rpm

I perosnaly have played with the only the small Dyno cams of simiilar lift and durration and my feeling is once you get around 240 or more durration then the torque starts to fall off on the low end.
Thats not what this guy wants or needs.

Normaly a higher stall would not be a problem but remember this is a kart with two kids in it weighing.....
300 pounds plus kids....
http://www.yerf-dog.com/manuals/3203A_T.pdf

So more stall on ther torque is actualy trouble.
He will by buying a lot of 91 belts for it.....

Now the marine grinds are intended for what now?
I believe a wake board are they not?
Thats a very narrow rpm range of opperation generaly speaking.
Lets watch a winch board in action and think about what its required to do
GRENCH WINCH SURF PULLY RUNS ON GAS MOV00120- YouTube
Not a lot of complexity here.
ON and off....
Since I am not an expert on cams and NR is I would assume the ground that thing to do all it can in a narrow RPM range.
OR we can assume it was ground for this aplication
http://www.youtube.com/watch?v=mRvVOMPtwiI&feature=related( thats very reasonanble to assume.... Ever notice all NR Honda parts are made in Thailand? ever wonder why? Spoilers lol )
Some of those are also GX motors at any rate.
And again not a whole lot of time spent between the throttle stops....

So from this it might be wiser to assume a short track kart grind would ave a little more finnese between the throttle stops.
BUT what do I know I am just guessing....
 
Newoldstock

Newoldstock

New Member
#18
#18
garredondojr said:
The spring upgrades for the clutch sound nice but not sure if the knock off tq converter will accept them. Bought the kart as a roller. No engine or converter. Definitly have a better understanding as to how weak the stock rod must be.
Click to expand...
OH shit.....

Now the haggas is in the fire.

What torque convert kit did you buy?
 
Newoldstock

Newoldstock

New Member
#19
#19
This young lad has a kart like yours garredondojr:
See the large secondary?
Thats a 7 inch....
my go kart - YouTube
You may have bought a TAV2 with a 6 inch.
This will be a problem because its going to try and turn the rear wheels 20% faster with 20% less starting torque.
Its probably why you asked for help now that I think about it....

Yup this is a pickle.
How to make the 6 inch work like stock and then better.
 
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