OLD BLUE,85 marathon re-construction

[danman]

Check out that torque

I wish I could get my clone running as good as yours, Sassy! I've been messing with jetting for 3 days and can't get the mix dialed in!!

[sassycat]

what motor ya runnin again? my 420 clone runs best at .040 but i went 2 and a 1/2 tousandths more to be a lil richer and its a tad rich..but tomorrow im installing the 35lb chrome silicone springs and shaft rockers and chromoly pushrods,,i can only get 4000rpm now so tomorrow im shooting for 5500-6000rpm,s is what there telling me anyhow
if you need to be a lil richer like i did i used a torch tip cleaner and used what fit the hole "kinda"took a lil at a time until a piece of wire i had that was .002 more than what i had previously so my main jet is at .0425
the 2 and a half thousandths made a big difrence in my case.

[danman]

I'm running a harbor freight 420 clone just like you

I used the torch tip kit I bought from Tractor supply, but it has these tiny drill bits that come with it instead of the "brush style" torch tip kits.

I'm not sure what the measurements are on them, I just did like you did and found the one that fit pretty well, then stepped it up one at a time. My new carb has the idle mix screw on it. Did you do anything to the idle jet on yours?

Where at in Florida do you live? I'm going to Orange Beach Florabama next week and debating on whether or not to take the buggy down there to cruise around on

[sassycat]

dunnellon fl rainbow river"withlacoochie river" area..the drill bit cleaners are best actually as they will give a better smoother bore,but both work well..inside the drill theres a .040 and a .045 and one bigger,in mine anyhow..
you need a cheap or good pair of dial calipers,,even 10.00 ones are better than nothing..with the dial you can zero them everytime and makes it easyer,if you cant figure how to use them i can help you out for sure
they come in handy for so many things..to mess with the carb jets you really need to know where you stand with calipers or a #drill bit set..both are nice to have..
my engine came with 3 jets,in my case the biggest was in the carb,,so i drilled with the cleaner bits like you have"but i measured them" and now have a .042 and a half,but if your still basic stock id say you need a .040 jet to be perfect..not sure what our stock jet is but i no its under .040
so with the extra 2 jets that came with it i have a .040 and a .045 extra, and the middle size between those 2 is in my engine..go get some cheap calipers with a dial..we can get you on track

[sassycat]

just learned you can NOT run champion shaft rockers with stock valves and push rods..you need 1/4 longer push rods"very cheap from geoff" and 1/4 longer stainless valves and new retainers and keepers to match

now to hopefully get it all apart and put the stock crap back,but leaving the new springs i put a drop of loctite on the studs so id better hurry back out there

[Pitbull Joe]

You're gonna been replacing the rear tires often from burning them up once you're done with that motor lol.

[sassycat]

wouldnt that be nice well after the spring change i still only get 4200 rpm and then it sputters like it needs more gas,but its running almost to rich imo..
gonna stop playin with it for now until i get a better carb.

[sassycat]

i did make me a cheap shifter that takes up no floor space
since i will be switching to a military theme soon i figure a m80 sitting on the back wouldnt look to outta place

it actually took a lil time to bend it right,but 1 click up for "so called neutral" 2nd click up is reverse.no rattles with rubber bushings and a lil extention added to the shifter.its a piece of small pipe and a nut welded on it with kwik steel epoxt holding the rope in..redneck art JACK!hahaha

[Pitbull Joe]

Hey! Now you're cooking with peanut oil jack...insert Phil's thumbs up here_____. LOL

[bansheemxer]

Originally Posted by sassycat

wouldnt that be nice well after the spring change i still only get 4200 rpm and then it sputters like it needs more gas,but its running almost to rich imo..
gonna stop playin with it for now until i get a better carb.

Carb isn't the issue right now. I tend to follow the "KISS" principle...Keep It Simple Stupid rule. Don't mess with a bunch of different variables at the same time.
The carb is good stock with main/pilot jet increase. < As long as you give the motor more air....(clamp on style filter etc...) in conjunction with a better flowing exhaust. Once that is in order and running great.... Now would be the time to look into internal mods like 1.3 ratio rocker arms/32lbs springs to take advantage of the extra lift in the valve train and all the extra air that the exhaust and intake are producing.... the timing key that sassycat mentioned that I'm missing out on is just the next step to success....or smiles with waking this motor up performance wise.