Honda 390 vs. Clone 420's

Kustrud

I have the Lifan and have been super happy with it. However, I want more power now of course....I cannot seem to find a Vanguard for a good deal and I would have to do a good bit more fab work, plus I like the pedal start. Having said this, would it be a safer bet to put some $$ into mods in a Honda opposed to a clone? I have the HD springs and no governor in mine but want some more. I can find these used cheap all over the place. Is the Honda quieter than the clones as well? What're the easiest mods to get the most power possible? What would no governor, HD springs, billet rod, high torque cam, new push rods, and carb jetting do for me? Would it be a big difference from what i have now? I dont want to hurt reliability and also just want easy stuff I can do on my workbench in the garage.

BGW

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Field6565

You won't get much more out of a genuine Honda other than reliability. Your 420 is basically a bored out 390. Buy a built 460 from Vegas if you want more power. If you want more from your lifan then do the basics. Remove governor...HD springs...advance timing...bigger cam...1.3.1 rockers.....shave and port the head...free flowing exhaust and intake....buy a tuned carb from Vegas. That will give you some more power for sure.

Kustrud

That's what I was asking, apologies if that was confusing. I mean, would it be worth it to do the Honda because of the reliability. Are they that much better over the clone in terms of quality?

Currently - On my Lifan 420 I have HD springs, governor removed, intake and exhaust, and Vegas Carb is on the way. If I'm going to spend the $$ for a cam, push rods, and bilet rod would a Honda be more reliable and quieter?

slonomo

Just a quick thought.... Once you modify and rev your stock GX390 past 3600 rpm you lose the "reliability" of the Honda engine anyway. If you were going to keep it stock with the governor on then yes, the Honda will be the best for reliability. But since you are trying to rev it up, it just takes that concept out the window.

Both clones and the Honda are "splash lube" which means the oil dipper on the connecting rod splashes oil on all the critical parts. At high rpm this becomes a concern, mostly for the connecting rod since there is no "bearing". That's what usually fails first. Frequent oil changes are key in any small engine, but more so on the clones and Honda singles.

The Vegas Carts engine addresses this with a billet rod with a bearing. Plus, they are designed to rev higher out of the box. The oil dipper on the billet rod is designed better for higher rpm oiling. Not perfect, but better.

jerryggable

Kustrud, I have the Lifan 420 in a go kart. When I put the billet rod and the torque cam I was really pleased with the increase in power. When you get the billet rod make sure you get the one that is 4.450", not the shorter one. The 4.450" inch connecting rod will increase your compression ratio with no other changes. It is 40 thousands longer than the stock rod. That is the advice I got from VC. I installed the billet rod and torque cam at the same time so I do not know which gave the most power, but together it was a very noticeable increase. I also had to install new guide plates because the stock ones would not fit the oversize pushrods. The only problem I had was that at around 6000 rpm I broke one of the Lifan rocker arms. Replaced them with stock Honda 390 rockers and have had no further problems. The stock Honda rockers are noticeably thicker where it counts. I try to keep my rpms to 5500 and below just to be safe since I do not have a billet flywheel.

Kustrud

Thanks Jerry, that info. helps! Makes sense too Slo with clones vs Honda past 3600 RPM. Hope I'm not hijacking my own thread but I also looked at the Predator V-Twin and the HF website said it revs to 4k. Is that true? 4k with the governor intact?? Or is it 3600? Could be a decent difference in speed once in high-gear. If it revs to 4k I may look towards that as well...

Field6565

400 RPMs won't matter much on top end speed. Your clone now with no governor and HD springs should turn 5000 RPMs. What exactly are you looking for in a motor? Top speed? Torque?

Kustrud

I don't know, just more power haha. I think one thing that is really hurting me is my clutch setup. Motor seems to have a lot of power it's just that it immediately bounces off the 4k rev limiter when I stomp it from a dead stop, takes off slowly in a very "low" gear, then the clutches finally shift out and it picks up speed good. 4k rev limiter is a 25 MPH max speed. It actually ran about 28 with a thicker drive belt for some reason - that I do not understand as I thought a thicker belt would be slower. I would like to run about 35-40 MPH and for it to be full of torque too. Torque and speed I guess to answer....I know I need to get rid of the rev limited with the new coil but debating putting anymore money into this or getting the Predator V-Twin or a Vanguard. I think building a Honda 390 is now not an option thanks to the input from ya'll.

slonomo

If your engine has a 4k rev limiter on the coil, no sense getting the billet rod unless you are changing the coil. 25 mph sounds about right. To get 28 mph you must have been higher on the rpm or going slightly down hill or down wind lol . Thicker belt will make lower gear ratio, usually slower top end.

The Predator Vtwin has been reported to have lots of torque at low rpm, very similar to a Honda Vtwin. Yes the revs will be limited, but if you aren't trying to achieve 30 plus mph then it would be a good powerplant.

Clutches mean a lot with golf cart performance. I recommend the Comet 780 primary and a new or good condition stock secondary, coupled with a factory width belt (usually 1 3/16"). This combo will be really good for any clone or Vtwin setup, unless it is built for huge power.

Slo

raydhd

Vegascarts is supposedly going to start selling modified predator Vtwins later this year.You might want to wait and see what comes off this and ride what you got.But if your antsy do whatever.