16 HP Duromax flywheel problems

Robert Yow

The magnet on my flywheel flew apart the other day and took the coil out with it too. My engine is stock except for jetting and better exhaust. I was wondering if the stock Honda GX 390 flywheel and coil will work on my engine. I don't think I need the billet flywheel since I am basically stock.
Anybody ever had this problem?

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

Streetbu

Yes it should hokt right on....

Robert Yow

While I have the engine out I was thinking of replacing the carb, springs, and flywheel key with the ones from Vegas Carts. If I go with the 8 degree key and get the head cut .05 do you guys think I will be able to still run regular gas. My cart is a 95 Ezgo, lifted with big tires.

Field6565

The head on my 420 is cut .050 and i am using a 4 degree timing key. I dont think you need that much advance with a cut head. Running on regular gas is no problem.

Streetbu

no 87 octane with an 8 degree key. 4 degree is max with 87....

sho305

I have this too. It would knock at low idle range rpm if the belt caught it, like if you slow with stock clutch and gas it before you stop. Now I put a duster on and it does not do that. I have 1.3 rockers, HD springs, header into car muffler, car airbox, etc, but stock block so far.

My flywheel has a screw in the middle of the magnet, its a lifan brand 420 from home depot online. I have been told none of them are good for over 6K and you should run a billet or honda flywheel if you put a cam in that goes higher rpm than stock. My tach gets funny I think I am around 5500 top rpm not sure. After about 5200 the tach stops. But I rarely get it up there that is 38mph on gps and now it goes faster with this clutch shifting better not checked it yet.

Another issue is lighter flywheels rev quick but can cause starting problems with electric starters/generators. I might lose my backup recoil start also. You also need a rod to run a cam. But very few break with stock cam that is unusual.

Robert Yow

Yea my magnet had a screw in it too but it had sheared off when the thing came apart. I don't know for sure what happened, but the coil is bent up too. The coil may have caught the magnet and busted it off. Anyhow, I am going to follow you guys lead and go with the 4 degree with .050 off the head and heavy springs. Where I ride there are some real steep hills, and I would like to get a little more torque to keep the rpm's up climbing the hills. Thanks for the help!

sho305

Work on your clutches!

That is a good setup it will rev nice and little more power too. If you can smooth off the cutter marks behind the valve in the ports they leave sharp edges you don't want, lap the valves in, and lap the flywheel to the crank a little.

Robert Yow

Ok I will smooth out the ports too. What type of clutch work do you suggest Sho?

sho305

Heavier secondary spring will keep the rpm up more at lower speeds, more spring in the primary will raise engagement for takeoff. It helps a lot because the clone tends to make torque at 2500 and max power 3500-4K, so closer it engages to 2500 and shifts at 3500+ the better it will go. Stock carts usually engage lower and some shift lower. If its a ezgo I don't know all the tricks but most clutches you can do that, buy the springs, etc. Some you can just put more preload in the secondary.