Springs and Rockers

[CRN13]

Background: I built a motorized drift trike with a gx200 clone and a gear ration of 4.2:1 with a goal of achieving at least 40km/h. i did everything i could to get to 40 but i only managed 38, i cut every second fin of the flywheel, backed out the throttle stop screw, reduced weight, everthying i could think of and what i have seen suggested online. i eventually bit the bullet and i have ordered a billet flywheel and rod, 36lbs dual valve springs and stainless valves, so i can remove the govner and safely thrash it to pieces and get to my goal. (and hopefully like 60km/h)

My questions are these:
1, will using 36lbs valve spring break the stock rockers and do i need to buy reinforced ones im worried they will break and destroy everything; and
2, does anyone know how strong dual valve springs will be if i remove the inner spring and only use the outer one?
cheers for your help in advance

 

[KartFab]

I thought you only needed 18 lb valve springs.

 

[CRN13]

Yeah I think your right right but I bought the 36's

 

[tuneman]

Before you seek more than 5500 rpm's I'd highly suggest billet rod. And flywheel. 36# valve springs are overkill. 18# should get you plenty of rpm's. Granted the spring pockets may require cutting to prevent coil bind. Anytime your replacing with heavier springs you will want to get stronger retainers, keepers,rocker arms, and chromemoly pushrods. A cam upgrade would be feasible as well

 

[landuse]

Pics of your trike?? Are you sure it can handle all that power?

Before you seek more than 5500 rpm's I'd highly suggest billet rod. And flywheel. 36# valve springs are overkill. 18# should get you plenty of rpm's. Granted the spring pockets may require cutting to prevent coil bind. Anytime your replacing with heavier springs you will want to get stronger retainers, keepers,rocker arms, and chromemoly pushrods. A cam upgrade would be feasible as well

He said he has a billet rod

 

[CRN13]

Haha yeah I think the trike will be fine I just don't any to destroy my engine. I'll see if I can get pics tomorrow it's dark here in aus atm

 

[tuneman]

Pics of your trike?? Are you sure it can handle all that power?



He said he has a billet rod

Yeah I missed that. Good luck op

 

[CRN13]

Is there any other parts I am missing for a simple safe governor removal??

 

[landuse]

Haha yeah I think the trike will be fine I just don't any to destroy my engine. I'll see if I can get pics tomorrow it's dark here in aus atm

Why I am asking is because you don't want the frame to twist and break like a pretzel with the added power

 

[CRN13]

Yeah that's cool the frame is made of 50x50mm square tube with a fairly decent wall thickness I built it overkill if there is such a thing. I forgot to add it has a straight pipe to.

 

[Badot]

Something's really wrong if it can't reach 40 km/h... I didn't have any problems getting mine going to a little over 50 mph with a 200cc clone with only a centrifugal clutch and the throttle stop backed out...

 

[CRN13]

What gear ratio are you running? my wheels are only 9" as they are in pvc pipe

 

[Badot]

I think it was geared at 45mph/3600rpm

 

[mckutzy]

Did you get a high flow air filter/carb rejet with that header?

 

[CRN13]

Do you mean the straight pipe? I made it myself. The carb and air filter at stock

 

[OzFab]

There's little point letting the engine breathe out if it can't breathe in! Get a high flow air filter...

 

[CRN13]

I drilled holes in the air filter cover. Haha don't know if it made a difference

 

[MancoGX390]

By getting a high flow air filter he means doing this to your clone. This is my GX390 with a high flow inlet and high flow exhaust. See with my setup how air is now alowed to flow freely into the carb rather than having to be sucked all the way down through the stock air filter assembly. I've noticed more power and much much snappier throttle response with the inlet upgrade. I recommend you getting a high flow inlet.

 

[rmm727]

Stock valves aren't going to like 36lb springs.

 

[CRN13]

Yeah that's why I though to purchase new SS valves I'm just worried about the rocker arms