GX200 clone help

[4wd_for_field]

hey there!
I'm just coming to the end of my build (seen here http://www.diygokarts.com/vb/showthread.php?t=13059)
and I'm starting to look at the engine.
I've just finished a custom throttle cable set-up, a custom stainless steel exhaust, and soon a ram air induction kit. i'm just wondering, what power( if anything :L ) do i stand to gain?
is there anything else i could do?
I'm pretty handy with a spanner and know my way around an engine so I'm not afraid to try something.
the parameters are that i have no money for big expensive cams or flywheels, and governor removal is out, as I don't want to blow my only engine.
i know it's a big ask but any help would be much appreciated!!
Thanks!

 

[buckeye]

I put a little cheater in my gov spring. Doesn't totally overide the gov, just gives a little more ooommmfff.
I took two zip ties. Cut one about a inch and a half or so. Slipped that in the gov spring. Then used the locking end of the other zip tie to lock it in.
Not my idea nor recommended for those that don't know what over zrevving can do. I don't go crazy wide open til the flywheel or rod make a big mess.

 

[Doc Sprocket]

Before ziptieing anything, be aware that you can back out the governor adjusting screw. Doing so will result in a governed maximum RPM of 4000-4200RPM (depending on engine). Takes mere seconds to perform and does NOT defeat governor operation. If anything breaks at this RPM, something was way wrong to begin with.

 

[kendelrk]

can we see the intake and exhaust? it sometimes isint necessary to put a bigger jet, but sometimes it is,most people say its not a cure all solution but alot of people use #90 jet with great result including me. so if you have your cable setup, exhuast and intake, you can by a spring on i beleive agk that will cheat the govenor, but keep you under 5000 rpm, creating a safe bracket,wont blow your motor, but youll get the oopmh your looking for, the governor gives you all the acceleration and then cuts you off, cheating it gives you tons of acceleration and when it closes it still leaves the throttle open a bit and you get a greater speed, or another way is if you look on the throttle plate with the silver arm, just above it is a screw with a spring,its a philips screwdriver head, pull it out, leave it on a bench, sometimes the motors cant hold the rpm because the carb wasnt properly tuned, but it usually can, and youll get some good increase there,sounds stupid, but take off your carb and make sure all gaskets are the right way, sometimes thesse motors have one upside down and it creates problems with lean-ness. use 10w-30 synthetic, its recommended by AGK, and also if you ever decide to yank the governor and you want to be extra safe, billet connecting rod, billet flywheel, tougher valve springs, thats the way to go, if you do that, you can have the governor out and run it full throttle all you want without problems, when i used to have a clone on my bike, and the throttle was still moved by hand, it was the biggest pain in the ***, i got maybe 20mph after the governor kicked in, me and my neighbor yanked it, and the way we always did it was to press the petal to full throttle and then reduce it to about 1/2 to 3/4 once we got moving a little bit and then if we ever needed an extra push wed give it wide open for about 1 second, theres not documntation about it, and people dont take lightley to it here, but somtimes motors do snap a rod, flywheel explosion is somthing that starts a big fight, so lets just say this, theres no evidence, but its been said to happen, if you want to be extra safe, billet and bigger valve springs is your way to go.hope this helped

 

[buckeye]

So toy storey ,a how to would help on that one.

 

[kendelrk]

buckeye, the screw stops the throttle lever from moving all the way, taking it out lets your throttle arm move further, thus pulling on the governor arm more providing more speed/RPM

 

[4wd_for_field]

well the intake is yet to be done, but it'll be 2 inch industrial pipe thats curved, with a cone filter up top. the exhaust i made out of a stainless steel quad exhaust, inch diameter, 2 foot long with a couple of curves (thats what she said ) i think i'll go with your idea toy story, sounds like the most reliable, plus i'm not doing this for top speed, it's gonna be a lean mean diffin' machine, so any torque/ power at the low end would be best!!

 

[kendelrk]

this might be some help http://www.affordablegokarts.com/performance_basics.php

 

[buckeye]

Ok then. That screw was out a long time ago. And don't blame ya. Wouldn't listen to me either. 5 cents, tons more acceleration and top end.

 

[4wd_for_field]

if i was to do what toy was on about, would i have to upgrade my springs? this really is on a shoestring guys...

 

[kendelrk]

no, its basically a string, that screw out, exaughst, intake, jet, those all go together, thats all you would initally need, now once you start taking the governor out, if you want to put in billet parts, upgrade your springs, if not, leave the stocks, and the reason is if you over rev the valves will float stopping complete engine failure

 

[4wd_for_field]

would I be able to bore out the old jet? or would I need to buy a whole new one? I think I'll stick with this to keep it reliable, and I have zero cash anyway. what kind of a gain we roughly talking? .5 to 1 HP tops I guess. Thanks for all the help guys!

 

[kendelrk]

you can do that, people have had sucess, but youd need a numbered drill bit set and the chart and alot of time to find out the size, and i dont know but from somewhere we read apparently just exaughst intake and jet, stock gave about 8.5hp so about 2hp gain

 

[4wd_for_field]

really that sounds like a ridiculous amount for simple mods but I'll take ye're word for it! only problem for me is while the jet is only $6 it costs around $80 for delivery to ireland also will i need to do any extra tuning after i put in the jet? or is it all plain sailing till one day it spectacularly explodes in my face (that, yet again, is what she said)?

 

[kendelrk]

yeah thats what we thought, we all read it somewhere, and when you put in the intake exaughst, whats its drawing dosent give enough fuel, upgrade the jet for more fuel, and your good to go, me and my neighbors have ran our old clones long, his has lasted 4 years, not problems but a carb gasket, and mine lasted 2 years, no explosions at all, he even crashed his kart, it flipped 7 times, remained upside down for about 15 minutes and still had the nerve to start up again when we turned it over without giving a problem

 

[Doc Sprocket]

Only re-jet if you need to. Don't let anybody tell you that you HAVE to install a #whatever jet just because you've done some mild mods. Let the engine tell you what you need. If you're careful about it, you can drill out your existing jet with precision drill bits. Yes, those will cost too, but maybe you can get them locally.

With everything set up as you want, install a clean plug. Start and warm the engine and go for a full-throttle pass. Cut the engine at full throttle and pull out the spark plug. Examining the plug will reveal whether you need to increase your jetting.

Regarding the governor screw- It works together with the hand throttle and governor spring tension to set the governed RPM. Normally, you would adjust this screw to meet the power equipment's (usual) specification of 3600RPM. backing this screw out will allow the engine to (usually) run up to 4000-4200. This alone will not require any further modification. No jetting, no springs, no nothing. Turn and go. I ran my GX340 at 4200RPM with no mods except a custom muffler for 4 years thru he//, no issues.

 

[devino246]

1)can we see the intake and exhaust? it sometimes isint necessary to put a bigger jet, but sometimes it is,most people say its not a cure all solution but alot of people use #90 jet with great result including me.

2)so if you have your cable setup, exhuast and intake, you can by a spring on i beleive agk that will cheat the govenor, but keep you under 5000 rpm, creating a safe bracket,wont blow your motor, but youll get the oopmh your looking for, the governor gives you all the acceleration and then cuts you off, cheating it gives you tons of acceleration and when it closes it still leaves the throttle open a bit and you get a greater speed,

or another way is if you look on the throttle plate with the silver arm, just above it is a screw with a spring,its a philips screwdriver head, pull it out, leave it on a bench, sometimes the motors cant hold the rpm because the carb wasnt properly tuned, but it usually can, and youll get some good increase there,sounds stupid, but take off your carb and make sure all gaskets are the right way, sometimes thesse motors have one upside down and it creates problems with lean-ness. use 10w-30 synthetic, its recommended by AGK,

3)and also if you ever decide to yank the governor and you want to be extra safe, billet connecting rod, billet flywheel, tougher valve springs, thats the way to go, if you do that, you can have the governor out and run it full throttle all you want without problems,

4)when i used to have a clone on my bike, and the throttle was still moved by hand, it was the biggest pain in the ***, i got maybe 20mph after the governor kicked in, me and my neighbor yanked it, and the way we always did it was to press the petal to full throttle and then reduce it to about 1/2 to 3/4 once we got moving a little bit and then if we ever needed an extra push wed give it wide open for about 1 second, theres not documntation about it, and people dont take lightley to it here, but somtimes motors do snap a rod, flywheel explosion is somthing that starts a big fight, so lets just say this, theres no evidence, but its been said to happen, if you want to be extra safe, billet and bigger valve springs is your way to go.hope this helped

My god man, PLEASE use periods, proper sentence structure, and paragraphs. Its darn near impossible to read this post! Now,

1)As its been said before, there IS NO cure all jet size. Ambient temperature, engine variations, altitude, and various other factors affect a/f ratio; jet accordingly.

2)Adjusting or removing the governor WILL NOT have any affect on acceleration. The governor limits rpm, thats it. Any acceleration difference your feeling is in your head.


3)Not necessarily. Holding the engine at high revs without a load can still cause internal damage.

4) Id comment if I could actually understand what you just said.

you can do that, people have had sucess, but youd need a numbered drill bit set and the chart and alot of time to find out the size, and i dont know but from somewhere we read apparently just exaughst intake and jet, stock gave about 8.5hp so about 2hp gain

Ive had luck with a pointed diamond rotary bit by hand. Just take a little of at a time and reinstall to check mixture. Again, you may not need to rejet. BTW, a local mower shop can order new jets for you.

 

[buckeye]

Well said.

 

[speedshopmike]

i asked this question on another forum and got nothing useful:
has anyone tried lightening their governor springs to achieve reasonably safe but higher governed rpm?
i'd like to keep mine to 5500 max.

 

[Doc Sprocket]

Years ago, I played with the spring tension to increase the RPM on a lawnmower I had that kept bogging down. At the time, I didn't own an IR tach, so it was all "seat of the pants" stuff. I never had it fail, but then, I didn't run it to insane RPM. If I had to guess, I'd guess it was up around 4500.