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liverider2003
04-19-2011, 02:11 PM
Hello everyone. Been reading for a while, but pretty new here nonetheless. I am, however, not new to karts/buggies and fabrication.
About 5 years ago now, I built a mini sand rail. It was a single seat full independent suspension and was powered by a honda CBR600 crotch rocket engine.
Picture of my rail is at this link(coudn't get my pic to upload):
http://www.desertkarts.com/off-roadcars.ivnu
It is the 4th picture down...black with yellow body panels.


Anyway...I learned a good bit about a lot of things while building that...especially about the engine...which came from pieces of wrecked bikes that I had to assemble.

I am building myself a smaller cart now. No suspension...just something easy to putt around on. But I still want it to be fairly quick with as much simplicity as possible. Because of this desire, I have decided to go with an Industrial engine.

I don't know much about them. I know how they work of course...and the basics.

But what I don't know is how to make one quick.

The engine I would like to use is here:
http://www.maxtool.com/us/products/DS16HPE.asp

Is this a copy of the Honda GX420 engine? If so, are there parts available for it around the web that I can use to modify this engine for more power and to safely sustain higher RPM?

If my understanding is correct, this engine(along with most others) is governed at 3600 rpm. With governor removed, what would be the maximum RPM range with the stock parts and stock setup? And can this level be raised safely? I am hoping to obtain a maximum of 6000 RPM. Is this doable on this type of engine without spending loads of money?(I ask about the money because if it would take a fortune to mnod this engine to what I hope to get out of it, I will just go with another bike engine...lol.)

Sorry this post is long winded. Just excited I guess...lol.

Nice forum you all have got here.

Thanks,
Corey

r_chez_08
04-19-2011, 02:35 PM
Welcome!
You are right! You are by no means new to fabrication!
Your sandrail looks beast!
That engine is not an exact clone, because as far as i know honda do not make a gx420.
If you wanted an engine to mod, you would want a clone, like this (http://www.harborfreight.com/13-hp-ohv-horizontal-shaft-gas-engine-66525.html)
Bearing in mind harbour freight are discontinuing these engines, you would need to get one fairly quickly. I know it is 3 less hp, but it is easier to find parts for, and a bit cheaper.
You could then modify this engine to rev higher and have more hp.
Depending on what rpm you want these are the mods i would suggest:
3600: stock
5000: de govern
5500: billet aluminium con rod and 18lb valve springs
6000 +: billet flywheel
Of course you would need mods such as carburettor mods and camshafts to get up to higher rpm.
If you want to keep it simple as far as mods, you could put on a good air filter, nice straight pipe, drill jet to richen the mixture and de govern.
Here are some sites that may help for parts:
http://www.affordablegokarts.com/
http://www.nr-racing.com/
Hope that helps
Rob

karl
04-19-2011, 02:36 PM
To get that engine reving to 6000 rpm you would need lots of stuff. Billet connecting rod, Billet flywheel, stiff valve springs, high flow intake+exaust, big carb jet, and maybe some other stuff. If you want cheap power, get a 2-stroke dirtbike engine. A 125cc dirtbike engine with an expansion chamber and 5 or 6 speeds would be better and cheaper. Plus- manual trannys are fun :thumbsup:

liverider2003
04-19-2011, 02:43 PM
To get that engine reving to 6000 rpm you would need lots of stuff. Billet connecting rod, Billet flywheel, stiff valve springs, high flow intake+exaust, big carb jet, and maybe some other stuff. If you want cheap power, get a 2-stroke dirtbike engine. A 125cc dirtbike engine with an expansion chamber and 5 or 6 speeds would be better and cheaper. Plus- manual trannys are fun :thumbsup:


I agree. However, when I built the last rail...I had no wife. Now I have a wife whom insists on being able to drive the kart...and she refuses to learn how to use a clutch of any kind to shift any vehicle...lol.
So I am stuck. I guess what I said before about "if it costs to much to get what I want out of this engine, I will go with a bike engine"...is just a dream...lol. The wife won't have it. I will likely just build this engine...or the one in the link above from Harbor Freight.

Thanks for the reply!

liverider2003
04-19-2011, 02:44 PM
Welcome!
You are right! You are by no means new to fabrication!
Your sandrail looks beast!
That engine is not an exact clone, because as far as i know honda do not make a gx420.
If you wanted an engine to mod, you would want a clone, like this (http://www.harborfreight.com/13-hp-ohv-horizontal-shaft-gas-engine-66525.html)
Bearing in mind harbour freight are discontinuing these engines, you would need to get one fairly quickly. I know it is 3 less hp, but it is easier to find parts for, and a bit cheaper.
You could then modify this engine to rev higher and have more hp.
Depending on what rpm you want these are the mods i would suggest:
3600: stock
5000: de govern
5500: billet aluminium con rod and 18lb valve springs
6000 +: billet flywheel
Of course you would need mods such as carburettor mods and camshafts to get up to higher rpm.
If you want to keep it simple as far as mods, you could put on a good air filter, nice straight pipe, drill jet to richen the mixture and de govern.
Here are some sites that may help for parts:
http://www.affordablegokarts.com/
http://www.nr-racing.com/
Hope that helps
Rob

Thanks for that information. I appreciate your input. I will do some more research!

liverider2003
04-19-2011, 02:46 PM
Where are you from in Northeast Ohio, Karl? I'm from a small town called Ravenna...in Portage County. One town east of Kent...Kent State University. I live in Florida now though.

karl
04-19-2011, 02:59 PM
I know where ravenna is, im pretty close. I live in leroy, but my property borders chardon (well not my property, im 13 years old lol) I think 16hp is fine stock , you can make a small buggy move over 40mph with a stock 16hp. You need a torque converter for this, I wouldn't use a cheap centripetal clutch on this.

anderkart
04-19-2011, 03:04 PM
I'm still not sure who makes those DuraStar engines. Awhile back I posted a thread about them with just a little info here at this link:-->http://www.diygokarts.com/vb/showthread.php?t=10742

Honda did make a GX420 model, and I'd guess the 16hp DuroStar is mostly a copy/clone of it. But as far a I know, none of the kart racing forums have posted any info about them yet so Its still kind of a mystery at this point.

The GX420 and 16hp clones usually end up with around 500-less max rpm that GX390/13hp-clones whether they're both just mild-ungoverned or built full race.

I'm guessing a 16hp DuroStar with a tuned 3-stage race header/race-type air cleaner and re-jetted would only wind out to around 4500 rpm max.

I have no idea if cams and other GX390 race parts would interchange on a the big DuroStar, but If I had to guess I'd bet they would.


You should register and sign up at this forum:--> http://karting.4cycle.com/
Then you can use they're search window. Try entering a search for "GX420", you'll find they have quite a bit of info comparing these 16hp big blocks to GX390's.
Then... you could enter a search for "GX390" and you'll get TONS of cool hard-core, race motor info :thumbsup:

r_chez_08
04-19-2011, 03:17 PM
Hi ander
Could you post a link to a gx420, as i am interested and have never seen one.
Rob

liverider2003
04-19-2011, 03:25 PM
Thanks Anderkart. I will check out that other forum.

And I don't have to use that engine. It is just something I ran across and for the price I thought I would do a little research. I mainly am interested in the 16hp for the torque. I am about 320lbs...6'6" tall...so I need the torque to get my big *** moving...lol. I would rather go with a clone that has more "known" options available to me for modifications. Would a gx390 clone 13hp be a safer bet as far as being able to find more variety of performance parts? I am in no real rush to finish this kart...so buying the engine stock...and building it up from there is probably what I will do. Unless there is some race engine out there already built that I could snatch up. I have been reading some about your kart Anderkart...what engine do you run and what kind of power do you put out? What mods are done to the engine? I am really just trying to feel out engines I suppose. I know I want to steer clear from any bike engines this time. Just am so new to the industrial type engines, I have no idea what to get. but I will check out that forum. It sucks there are only 24 hours in a day. There is so much to read.

Thanks

r_chez_08
04-19-2011, 03:37 PM
I had a little read on the forum ander posted. From what i read the 420cc motor is a bored and stroked 13hp clone, so the internals should be the same. However somebody on the forum was building one up and needed to machine stuff for clearance issues so the 13hp woukd probably be a better bet.
Where do yu intend to ride, and what top speed are you looking for? Im sure either engine and a $330 comet 40 series would be an awesome setup.
Rob

anderkart
04-19-2011, 04:08 PM
Hi ander
Could you post a link to a gx420, as i am interested and have never seen one.
Rob


Ive ran across lots of references to GX420 engines over the years and had always assumed Honda made that model, but after more research I just now learned those references were to 16hp clones. Not genuine Honda's

You were right Chez, I was wrong :thumbsup:

karl
04-19-2011, 05:20 PM
I would check out arc racing http://www.arcracing.com/servlet/StoreFront You can see prices and selection of tons of industrial engines

liverider2003
04-19-2011, 07:21 PM
Where do yu intend to ride, and what top speed are you looking for? Im sure either engine and a $330 comet 40 series would be an awesome setup.
Rob

I intend on riding it on flat pavement/roads and on hard packed dirt trails(non-hilly...fairly flat). I would like 45-55mph. I wouldnot complain if I got more than that...lol...but I would be pleased with 45 to 55 mph.

I don't plan on using a torque converter. I would rather use a clutch...mainly so I don't have to fuss with extra stuff(jackshaft...more bearings...etc).

My rear tires will be 15" diameter. With 5:1 gearing I should be around 45mph at 5000rpm. But if I could get 5500 rpm or 6000...out of 16hp...I would be happy.

anderkart
04-19-2011, 08:57 PM
Would a gx390 clone 13hp be a safer bet as far as being able to find more variety of performance parts?

what engine do you run and what kind of power do you put out?
What mods are done to the engine?

Yeah a 13hp from harbor freight would probably be a safer bet for speed parts fitting.

I'm not sure how much hp my Tecumseh Star engines have. I bought them used from a guy that took them in trade for money owed, so I didn't get to talk to the dude that had them built.

I know some kart shop called A-1 racing blueprinted them, I can see they've both had block girdles installed so they've probably had lots of other speed parts and mods done. They're at least 20hp, but maybe more. I've ran across a few other used Star engines for sale since I found mine, they're usually priced between 3 and 5 hundred.

liverider2003
04-19-2011, 09:15 PM
Completely in another direction....but does anyone know anything about the KT100 engines? 2 cycle...high revving.But what about torque? Will it get me off the line?

I ask because I have one available to me from friend...on the cheap(I work for a beer company...trading beer gets a long way).

anderkart
04-19-2011, 11:17 PM
KT100's are cool, they got pretty decent low end torque for a small 2 cycle.
Check out this video to get a bit of a feel for how they accelerate and run:

(those Kt's are geared to hit about 60 on this 1/5 mile track)

http://www.youtube.com/watch?v=DOX4Tq26woo

r_chez_08
04-20-2011, 01:34 AM
Ive ran across lots of references to GX420 engines over the years and had always assumed Honda made that model, but after more research I just now learned those references were to 16hp clones. Not genuine Honda's

You were right Chez, I was wrong :thumbsup:

:arf: Ok, just wondered if it was like an "x" gx model like the gx110. On the 4 cycle forum they do call it a gx420 clone though.
Rob

liverider2003
04-20-2011, 12:58 PM
Cool video Ander! So they need to be started with a kart starter.
I did some further research on them and decided it is not the way to go for me.That seems more for the "racer"...which I am not and don't plan on it.

So...some more questions. Found some engines I am hoping some of you can tell me anything about.

Check out this one:
http://cgi.ebay.com/ebaymotors/Kart-Racing-Briggs-Raptor-Engine-/110676399574?pt=Race_Car_Parts&hash=item19c4d3d5d6

From the listing description...can anyone estimate what sort of hp and torque it might put out. Say max rpm is 7500. Not sure it if it is accurate or not...just what the seller claims.


And then there are these clones:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=310225357611&ssPageName=STRK:MEWAX:IT

This one claims to get about 11hp with its mods. 6000 rpm. Any speculation on torque specs? I am thinking this would be a possible winner for me. Its just that I would like for it to accelerate quickly, but also have decent top end. This is pretty much bolt on.

Any thoughts?

j.concepcion54321
04-20-2011, 02:41 PM
have you considered using a sled engine?? they put out alot of hp and rpms. and if you get a full sled you can use the clutch and sprockets and everything straight from the sled and just bolt it onto your frame really.

liverider2003
04-20-2011, 02:47 PM
have you considered using a sled engine?? they put out alot of hp and rpms. and if you get a full sled you can use the clutch and sprockets and everything straight from the sled and just bolt it onto your frame really.

I have...and I have ruled it out because I don't need quite that much power...especially if my wife will be driving it. Also, I have limited access to any sleds being in florida. Every single thing I need would have to be ordered and shipped...including the motor. I would rather not deal with the freight charge.

But if I ever build another large fully suspended buggy I would consider one for sure!

Thanks for your input.

anderkart
04-20-2011, 03:51 PM
Cool video Ander! So they need to be started with a kart starter.

Check out this one:
http://cgi.ebay.com/ebaymotors/Kart-Racing-Briggs-Raptor-Engine-/110676399574?pt=Race_Car_Parts&hash=item19c4d3d5d6


And then there are these clones:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=310225357611&ssPageName=STRK:MEWAX:IT

Any thoughts?

Yeah Kt's dont have pull-starters, you could always skip the clutch, go direct drive and do the push-start thang, but that pretty much sucks...

That raptor engine you found needs a separate kart-starter just like those Kt's and My Star race engines. Like my Star, It also runs on Methanol (instead of gas) which is a hassle because you have to drain and flush the fuel tank/carb and also change the oil after every day of riding. Methanol allows race engines to be built to gain around 20% more power but it also requires much more maintenance to make-em last.

Your ebay BSP clone would be a cool choice but you could save quite a bit of money if you just bought it directly from the source at Arc racing instead:-->http://www.arcracing.com/servlet/the-5/Box-Stock-Project-BSP/Detail

That ebay seller probably just buys those engines from Arc (w/the cheapo muffler) and marks-em up...

The Arc BSP engine doesn't come with a header, but you could order this one that comes with a MUCH better race style muffler and still save $$$:-->http://www.arcracing.com/servlet/the-453/Box-Stock-Project-ARC/Detail

Arc has some better tuned/3-stage headers
on this page--> http://www.arcracing.com/servlet/the-HP-Engine-Parts-%26-Accessories/s/151/Categories

You realise those BSP clone engines come with a pulse fuel pump but need an external fuel tank right?
(Its a good Idea to get the fuel tank off the hot engine both for performance and safety reasons.)

You could install a race style fuel tank like one of these:--> http://www.out2win.com/catalog/fueltanks.html

Or, you could mount any type fuel tank anywhere you wanted. My karts fuel tank is mounted way down on the floor below the steering wheel, so you can see those pulse fuel pumps will draw fuel from just about anywhere that's convenient to mount your tank:

http://i72.photobucket.com/albums/i172/Mybigpics/010-Copy.jpg

liverider2003
04-20-2011, 04:22 PM
Yeah Kt's dont have pull-starters, you could always skip the clutch, go direct drive and do the push-start thang, but that pretty much sucks...

That raptor engine you found needs a separate kart-starter just like those Kt's and My Star race engines. Like my Star, It also runs on Methanol (instead of gas) which is a hassle because you have to drain and flush the fuel tank/carb and also change the oil after every day of riding. Methanol allows race engines to be built to gain around 20% more power but it also requires much more maintenance to make-em last.

Your ebay BSP clone would be a cool choice but you could save quite a bit of money if you just bought it directly from the source at Arc racing instead:-->http://www.arcracing.com/servlet/the-5/Box-Stock-Project-BSP/Detail

That ebay seller probably just buys those engines from Arc (w/the cheapo muffler) and marks-em up...

The Arc BSP engine doesn't come with a header, but you could order this one that comes with a MUCH better race style muffler and still save $$$:-->http://www.arcracing.com/servlet/the-453/Box-Stock-Project-ARC/Detail

Arc has some better tuned/3-stage headers
on this page--> http://www.arcracing.com/servlet/the-HP-Engine-Parts-%26-Accessories/s/151/Categories

You realise those BSP clone engines come with a pulse fuel pump but need an external fuel tank right?
You could install a race style tank like one of these:--> http://www.out2win.com/catalog/fueltanks.html

You could mount any type fuel tank anywhere you wanted. My karts fuel tank is mounted way down on the floor below the steering wheel, so you can see those pulse fuel pumps will draw fuel from just about anywhere that's convenient to mount your tank:

Its a good Idea to get the tank off the hot engine both for performance and safety reasons.



You the man.Thanks for all that info. Yes...I will steer clear of any engines requiring methanol.

And yes I do realise about the fuel tank. I plan to mount it exactly where you have...haha. I am going to go check out those links now and see if I can make a decision. If it doesn't work out for me...I can always resell it and shop for a different engine.

Thanks for the help.

Corey

anderkart
04-20-2011, 07:02 PM
Yer welcome Corey.

Torquerolljoe
04-22-2011, 08:55 PM
I called AGK about the Duromax engine before I bought it and was told that most parts from a 390 fit including ARC rods. Give them a call and they will be glad to help you out!! I have not started building mine up yet, but I have a Comet 40 series waiting to be bolted to it!!! First mods are rod, cam, valve springs, and billet flywheel. I know, I can get an atv or sled engine for cheaper that modding!! I have a Honda 400ex motor waiting on a big bore kit. I just like modding and building for the fun of it!!! Good Luck!!

Joseph

r_chez_08
04-23-2011, 06:58 AM
nice! this ride should be sweet, especially with the 40 series.
Rob