Need advice with 420cc clone

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pgreen491

New Member
#1
#1
I have a 16hp duromax clone and was told on diy go kart forum to ask my questions here. I dont race it just want more power. I currently have air filter,
header, the gov. has been removed, billet flywheel and rod.
I need advice on the cam I was thinking the agk .360 lift?
what valve springs?
how much can I mill the head?
timing?
I was going to get a mikuni 34mm carb but everyone seems to like the tillotson,
which one do I get and where is a good place to buy one I was having trouble finding the tillotson.
I was also considering the agk big valve head, overkill for the cam?
thanks for any help
 
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hd94vett

Member
#2
#2
I was thinking about putting this motor on my go kart, how fast is this motor stock? Are you running a chain clutch, I was looking at this motor at Harbor Freight two days ago. I know Dennis Kirt sells Mikuni carburetors but I am not sure on Tillotson. Did you try Bills Kart Shop, if he dosn't have one he would probably know where to get one.
Mike
 
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pgreen491

New Member
#3
#3
When I first got it I removed the gov. before the install, so I couldnt tell you how it ran before that but its on a 100 lbs. frame, enforcer 10 tooth clutch 54 tooth on the axle with 15'' tires, it will run somewhere in the high forties but the low end torque is great,
anything other than dry pavement it goes sideways. I got mine from ebay for 299.99
havnt had any problems with it what so ever just want to get the rpms up alittle. I would go for it on your kart.
 
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hd94vett

Member
#4
#4
I was having trouble finding a clutch for the 1" shaft, would you know a good brand of clutch that will hold up to this power? I seen about 100 clutches for 3/4" shaft but only 1 for the 1" shaft and it was a 14 tooth.
Mike
 
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pgreen491

New Member
#5
#5
I burnt up two 13hp clutches I had laying around and then bought the enforcer it was a little expensive but it holds up great. I got it from heeters I paid like 220.00 for it, I was going to get a torque converter but the 40 series will only go to 18hp and anything bigger than that were outrageously expensive. Don't waste your money getting a cheap clutch with this engine the torque will eat it up. I imagine the 14 tooth you found was noram 1600, thats one of the clutches I burnt up.
Get the enforcer or the more expensive bully or something like that.
 
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hd94vett

Member
#6
#6
Are you running a #35 chain, I was just wondeing if the 35 chain will be strong enough? I also have a split sprocket on the axle will this be a weak point? Would I be better off with a solid sprocket?
Thanks Mike
 
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pgreen491

New Member
#7
#7
oddly enough I originally ran a 35 chain with a split sprocket and it flew off a few times and had to be readjusted a lot. Im sure you could run race grade chain but I switch to 420 motorcycle chain because I wanted to change the axle sprocket anyway and it holds up great. If you are going to get this engine parts aren't cheap and it a heavy engine I went from band brakes to mechanical calipers to hydraulic brakes just due to the added weight.
In the long run its worth it tho you cant match the torque.
 
texasfabguy

texasfabguy

New Member
#8
#8
pgreen491 said:
oddly enough I originally ran a 35 chain with a split sprocket and it flew off a few times and had to be readjusted a lot. Im sure you could run race grade chain but I switch to 420 motorcycle chain because I wanted to change the axle sprocket anyway and it holds up great. If you are going to get this engine parts aren't cheap and it a heavy engine I went from band brakes to mechanical calipers to hydraulic brakes just due to the added weight.
In the long run its worth it tho you cant match the torque.
Click to expand...
What brand of chain were you running?
 
texasfabguy

texasfabguy

New Member
#10
#10
hd94vett said:
I was having trouble finding a clutch for the 1" shaft, would you know a good brand of clutch that will hold up to this power? I seen about 100 clutches for 3/4" shaft but only 1 for the 1" shaft and it was a 14 tooth.
Mike
Click to expand...
Your going to want a 14 tooth or bigger for a 35# chain. I turn my cranks down to 3/4" so I can run better clutch's. I have a Tomar 2 disc on my 420.
 
texasfabguy

texasfabguy

New Member
#11
#11
pgreen491 said:
Dont remember it was last year
Click to expand...
If it was not a gold chain than its undstandable why.cheap black chain won't work with that much torque. I'm thinking you mite have had problems with your clutch because of heat,most clutch's are set with the engagement set to high for big cc engines.plus to high your wasting all that good low end torque by passing it up before it engages.
 
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hd94vett

Member
#12
#12
Thanks for the advise on the chain, I was not sure the the 420 would fit a 40 or 41 sprocket. The 420cc engines seem to have the electric start do they make any without it? I say some engines on e bay, are most of the clones the same quality or are some better than other?
Mike
 
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pgreen491

New Member
#16
#16
its on a kart and I have 1500 to 2000 to spend on this, i just ride it around when we go to our cabin it is flat roads. it takes off good now but the top end doesn't scare me, I would like to run 65 plus.
 
Ibanez616

Ibanez616

Member
#18
#18
You need to match your head, cam and carburetor. So say you want X amount of lift in a cam, the head will need to be able to flow enough air for accommodate that extra lift. Now since you have more air coming in, you will need more fuel. This is where you pick out what carburetor is best for your combo.
 
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pgreen491

New Member
#19
#19
Ok well say im running a .360 lift cam will a ported head do or will I need bigger valves? If I do need bigger valves how big can I go without needed them? Also is the more expensive torque converters worth it I looked at the 40 series but it will only hold up to 18 hp. The others I found were jr. dragsters and thy were expensive. I was hoping to get 7000 to 7500 rpm out of the engine is this doable?
 
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