Looking for some advice on some mods I am thinking of doing on my 420cc lifan.
Either a gx390 carb or mikuni from AFG or NRR ?
For the Exhaust I will weld my own but what muffler?
32lb valve springs?
Advance timing 5-6 degrees?
Best way to set up a fuel pump? Does using the intake fittings take suction away from the intake?
And a big question I have is should I remove the governor?
Thanks all and merry Christmas

Ive byassed the governor in mine and have no problems, yet.
I've been consdering doing some upgrades to mine as well.
Was looking at the basic air intake/header route but on the intake what do you do with the valve cover breather as I do not feel like spendng an extra $20 to buy the filter they sell for that. Could I get just as much increase in airflow my drilling small holes in the plastic airbox cover?
With the exhaust, i currently have a threaded 3/4" pipe pushing into the exhaustport that runs about a foot back straight to a typical screw on lawn mower muffer. Will a header give me that much more flow?

What are the pros/cons of advancing the timing?

Ive byassed the governor in mine and have no problems, yet.
I've been consdering doing some upgrades to mine as well.
Was looking at the basic air intake/header route but on the intake what do you do with the valve cover breather as I do not feel like spendng an extra $20 to buy the filter they sell for that. Could I get just as much increase in airflow my drilling small holes in the plastic airbox cover?
With the exhaust, i currently have a threaded 3/4" pipe pushing into the exhaustport that runs about a foot back straight to a typical screw on lawn mower muffer. Will a header give me that much more flow?

What are the pros/cons of advancing the timing?

Yes

Walkers what size boat and prop do you have on it. And what kind of speed do you get?

I have a 14 vhull and run a 8x4 prop. I get 17 mph with just me and 14mph two people deks and gear not bad but It is getting hot and not restarting until it cools. So I am debating on changing to a 1436 boat, 7x4 prop or trying to get more power out of it.

ImageUploadedByTapatalk1356977527.069601.jpg

I ordered a flange and piece if pipe. I took off the old muffl

Oops hit send on accident. . . Muffler and header that cast iron junk is heavy and it was blocking the exhausts port by at least 10% to 15%. I will post back how it works out.

Yeah I couldn't believe how much they block the port.

I built one on a SD frame and have been running it all year. I had the same dilemma about the intake so I drilled additional homes in the plastic air intake cover to allow additional air. I also built an exhaust for it and gained close to 500 RPM’s I have also removed the governor.

After duck season I will add the remote fuel to it

That is cool, I really like how tidy it all is.

Hows the motor enjoying having no governor, no damage? Have you done the value springs?
I've just taken the governor out of mine but haven't had the apples to rev it right out yet.

My concern with removing the governor is if ya hit a log and the prop comes out of the water it may over rev the motor. Is it common to have no governor on a mm.

Your surface drive looks good. I thought about trying to build one instead of the long tail but it seems like a whole different set of problems to work out.

not to derail but since so many of ya'll have these clone motors, do they have alternator output? I bought a maxtoll 16 hp for my go-devil crawfish LT and was curious about this.

Mine is supposed to be 18 amp. I haven't checked it but so far my battery is staying charged. I only have running lights and the electric start to draw it down. It's a lifan from homedepo. The electric start and charging was a selling point for me. My first boat had a 15hp outboard, I never want to pull start a motor again.

Mine said it has a low amp charging system but I don’t take chances and always put the battery on the charger. I am sure no matter what they say if you have running lights on, and run a spot light you are most likely drawing more amps then the motor can produce.

Mine is also a 16HP Duramax from Maxtool

2013-01-11 21.55.51.jpgHeres an update from the land of the long white cloud.

Exhaust done, governor gone and remote fuel. Still waiting on the lawn mower place to open to get valve springs.

Guys these builds look good,and these motors are priced right. What do you think your Motors with frames weigh?Hard to see in the pics but did you guys just use bushings for the lower part of the shaft? Just curious,thinking about building one in the off season for my 1448.

The gx390 parts will fit onto your "gx420" clone. I just put an s bend header and the air filter upgrade as well as removing te governor on my 16hp maxtool and it is strong. I seriously recommend this combination as it isn't expensive and really wakes this engine up.

I had a Honda gx 390 and did all the mods. Tricked out big time. Not worth it. Dumped about $ 800 then dumped it and upgraded to the 23 Briggs.

I have a caged needle bearing at the bottom, a bushing in the center and a tapered roller bearing at the top. Three seals on the bottom and one at the top.