clone trouble starting

S1att3r

S1att3r

New Member
#1
#1
I replaced the throttle and throttle cable on my minibike yesterday since the last time the bike was rode the throttle stuck wide open and was ripped off of the handle bar when attempting to shut the bike off. The bike sat for about a year since then. Ever since I got the throttle hooked up the bike has been near impossible to start. The majority of the time the bike starts it runs at a very low rpm for a few seconds before dying. Any amount of throttle change or choke change instantly kills the bike. The two times I was able to get it to run at a normal rpm it would run only about 10 seconds.

So today I took it to work with me and worked on it when I wasn't busy. I drained the tank and carb and changed the oil. It still wouldn't start and the few times it did it ran at a very low rpm. So I then reset the valve lash and tried starting again with no luck. Then reset the coil gap. I was able to get it started twice out of a dozen times trying and it ran fine when I was giving it slight throttle. As soon as I let off it would die.

I also cleaned the carb as best as I could since I was unable to remove the jet and emulsion tube. I also drilled the idle jet out with a number 76 bit on a jet out of another carb and placed it in the carb.

Engine specs are:
stock crankshaft
billet rod
flat top piston
billet flywheel
Blackmamba jr. cam
PORTED/MILLED 18CC HONDA HEAD: 27MM/25MM VALVES, SPRINGS, RETAINERS, LOCKS
Item# store_item-121797 , SELECT AMOUNT YOU WANT MILLED OFF: NO MILLING
hi flow air filter and exhaust
coil replaced when engine was rebuilt
140 emulsion tube and I believe a .038 jet.

Im going to try and take the carb apart and clean it again since I now have access to the proper screwdriver.

Sorry for the wall of text.
 
buckeye

buckeye

Well-Known Member
#2
#2
You have tried everything I would do. Except what you are planning.
Hopefully that does it. One last good carb clean.:thumbsup:
 
S1att3r

S1att3r

New Member
#3
#3
Ever since I put all that on the engine it has been hard starting. I would always have to give it a slight amount of throttle to get it started but it would start in about a dozen pulls are so.
 
C

Camjamsdad

Active Member
#4
#4
Bike sat a year? Stock carbs are cheap. My time is money. I've spent a lot of time cleaning old carbs and they never run right. But you gotta try I know. You can't even give up if you didn't try first, right?

But with your mods I would buy a bored reworked stock carb or the 22 mikuni.
 
OND

OND

#5
#5
I would clean that carb real good, this ethanol based gas is junk. It will build up in your tank and your carb. I've found two places locally to buy ethanol free gas and I'm going to get me 5 gallons just for the mini 's and karts.
 
buckeye

buckeye

Well-Known Member
#7
#7
I have one with that box stock legal carb. Made a bit of difference. Need a header too. And springs, and billet flywheel and a billet rod....
 
OND

OND

#9
#9
Anything is possible, flywheel key could of sheared. Have you pulled the valve cover to see if everything looks ok in there.
 
S1att3r

S1att3r

New Member
#10
#10
Yes I did everything looks fine under the valve cover. When I did get it to run it was at a very low rpm and it was popping through the exhaust and the carb.
 
OND

OND

#11
#11
Have you tryed a new plug yet, always best to try the simple stuff first ? Then I would pull the blower housing and take off the flywheel nut and see if you can tell if the key is sheared.
 
S1att3r

S1att3r

New Member
#13
#13
OND The plug that's on it is a ar3910x and when I pulled it I cleaned it with a wire brush on a drill.

buckeye I set the lash to .003 exhaust and .002 intake. It might need to be loosened up just a hair.
 
J

Jrdragbike

New Member
#14
#14
S1att3r said:
OND The plug that's on it is a ar3910x and when I pulled it I cleaned it with a wire brush on a drill.

buckeye I set the lash to .003 exhaust and .002 intake. It might need to be loosened up just a hair.
Click to expand...
Try a new plug, of that dosnt work try to idle the bike up yes it's a simple thing put pulling your throttle maybe made it strip out
 
R

RCB19

New Member
#15
#15
Have you tried increasing the size of your low speed jet? If using a stock carb configuration that will help these tings start much easier. Stock size is .016 and alot of guys end up around .022
 
D

davidlamb78

Member
#16
#16
Is the low speed jet under the needle? I think my stock carb had a plug over it. I almost tried to open the plug by lightly drilling in, but hopefully stopping before carnage ensued. Most folks told me the job was difficult and that buying a stock carb with the needle in place was the way to go. I'm only saying this in case the OP has a similar setup on his carb.

I'm running the cheater carb from Dover on my kart now, and I like it a lot. I'd recommend it. There are plenty of good options, but I just did a rejet with the e-tube and air cleaner on my mini. Mine starts easily with one or two pulls. I'll look into the low jet on my 97cc doodle bug anchor.
 
C

Camjamsdad

Active Member
#18
#18
I think he's talking about the idle bleed that's held in with the idle screw. The little black thing under the black plastic idle screw. Be careful over doing it. I did mine a couple sizes, I liked it, went up a couple more, liked it, well being greedy I think the 3rd time will be even better. Bike wouldn't idle for $hit. Back to stock for now. I bought 3 new ones to try again. This time I'll stop before I go to far. Yeah right that's why I bought 3
 
Last edited:
J

Jrdragbike

New Member
#19
#19
Camjamsdad said:
I think he's talking about the idle bleed that's held in with the idle screw. The little black thing under the black plastic idle screw. Be careful over doing it. I did mine a couple sizes, I liked it, went up a couple more, liked it, well being greedy I think the 3rd time will be even better. Bike wouldn't idle for $hit. Back to stock for now. I bought 3 new ones to try again. This time I'll stop before I go to far. Yeah right that's why I bought 3
Click to expand...
You guys men the idler jet
 
C

Camjamsdad

Active Member
#20
#20
I've heard it called many things. Low idle jet, low speed jet, idle air valve. Whatever it's called you can't miss it. Pulls out. Take your number driil set, or buy a set, poke a bit in the hole. If you its too loose then try the next size until you can't poke the bit through the hole. Whichever one just fit is your size. Pick a bit two or three sizes bigger and then carefully bore the hole bigger. Reinstall. Test start it. Repete. Screw up and go too big and you'll be asking who sells them. It was either arc or bmi. I think.

After market factory carbs have an adjustable idle air screw back by the manifold, they're broke off at the predator factory after they set it. By design.
 
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