Sir, you have low compression. Should be around 90-100. This will make it difficult to crank. Under stock configs your timing should be in the area of 26 degrees I think. A premium fuel blend will open that gap a bit. As to troubleshooting wiring...I would have to have my hands on it. Many techs get lost in wiring problems. Those things are a pain to track down sometimes. Good luck.
Newbie Engine Trouble
- Thread starter ADDPJ
- Start date
Karttekk
Well-known member
Pick up an inline spark tester, it goes between the plug and plug wire. Pull the rope and watch for spark through the tester. Crank the engine using the starter, look for spark in the tester. If you have spark during the manual pull and not with the electric starter cranking you have a grounding issue or safety switch problem of some sort. Report back with results.
ADDPJ
New member
I appreciate your simplified explanation. I hate wiring.lol...
Here's what i do know about the current setup:
Prior to me removing the engine the starter worked and started the motor after i had replaced the solenoid.
There is, what i believe, is a kill switch in the dash, but no matter what position the switch was in the engine would still start, so i assumed it to be bad? it is 10+ years old.
The key would turn and start the engine but i would have to turn the engine off at the on/off switch on the engine the key would not do it.
I do not know how its supposed to be "out of the box" so i don't know if the key is supposed to turn it off and the switch is busted or you just hit the kill switch? This cart had been sitting in my in-laws garage for quite a while unused till my son found it...so i have no prior knowledge of it.
There are 4 wires from the key switch to the engine...
red to solenoid
yellow to oil pressure switch
black to coil ( the coil on this engine has a tail w 3 wires on it)
Green - was not hooked up to anything but has a ring end on it ( i'm assuming its a ground if it has a ring but the engine ran w/o this attached to anything when i got it)
Current Set-up:
Same as previous....but the yellow wire from the ignition now goes to the coil since the oil sensor is gone. The start will not do anythign unless that yellow wire is hooked up.
i do know the green wire and one of the two "kill switch" wires share a port in the key/ignition plug and the black wire from the ignition to the coil share the other wire.
I hope that helps. I assumed the wiring was good any maybe the engine wasnt starting due to a timing issue but i can start the engine with the rope immediately turn it off and try the key but no go.
ADDPJ
New member
Suggestions? Change the head gasket try again?
Denny
Canned Monster
Your compression is fine. Big Wes is kinda leading you astray. These engines have a compression release therefore compression testers don’t really work on these engines. I have a feeling you have a bad ignition switch. Try temporarily clipping the green wire from it see if that works. Disconnect the yellow wire for the low oil sensor while you are at it.
ADDPJ
New member
You got me right before i was going to start dismantling that thing. Although when i try to look that stuff up the answers are all over the map i see anything from 60lbs all the way through 118...
I have a basically new predator sitting in my garage i'm gonna see what that gives me for compression.
The yellow wire is connected to the coil as i had removed the oil switch when i had it apart, and the green is still attached to nothing....
Denny
Canned Monster
I still think it is the ignition switch. Try disconnecting wires one at a time, then try to start.
madprofessor
"Loose Cannon Creations"
The fact that turning the key off once it's running doesn't kill it is very telling. Assuming you have to ground out power to the coil to kill the engine, the keyed ignition switch should have a ground wire to do that, likely your green wire with ring terminal. With it not grounded to anything, it makes sense the motor would keep running when turned off.
That also means you SHOULD NOT have to turn the key on to pullstart it, should crank right up, turned on or off.
Test for this, then ground the green wire and test again.
None of this means you definitely don't have a bad ignition switch, you still might. Use a jumper wire straight from the battery to the starter solenoid to spin it over. If it cranks up, it's a bad ignition switch.
That also means you SHOULD NOT have to turn the key on to pullstart it, should crank right up, turned on or off.
Test for this, then ground the green wire and test again.
None of this means you definitely don't have a bad ignition switch, you still might. Use a jumper wire straight from the battery to the starter solenoid to spin it over. If it cranks up, it's a bad ignition switch.
ADDPJ
New member
That also means you SHOULD NOT have to turn the key on to pullstart it, should crank right up, turned on or off.
--Yes it starts with the rope with the key off, just takes a few pulls
None of this means you definitely don't have a bad ignition switch, you still might. Use a jumper wire straight from the battery to the starter solenoid to spin it over. If it cranks up, it's a bad ignition switch.
-- The starter turns and spins the motor over now when i turn the key, the motor just doesnt start.
Bansil
Painter of gnomes....
Do you have a multimeter?
What I would do is disconnect everything, except battery ground to frame.
Your coil has a ground wire to kill engine when grounded to frame/battery negative.
Use a meter to determine which wire has continuity to mounting screws/flange of coil, this will be ground/kill wire when grounded out.
So with coil not ground, pull start and it should run, ground wire to negative to kill it.
Now unground coil "kill wire".
The solinoid is basically a magnet that pulls a plunger connected to a small pinion gear that will engage /"popout" to turn fly wheel.
When starter/solinoid are mounted to grounded frame, they are happy and ready to work.
The main positive wire from battery should be attached to big post on solinoid with a secondary big wire going from other big solinoid lug to starter.
It will not turn over because those lugs are not connected yet....
So if you connect a positive wire from battery to the smaller post on the solinoid, solinoid should "click" and complete circuit to engage armature to spin and pinion to pop-up and engage flywheel.
Since coil is not grounded, engine should run..
Ground coil to kill.
That is a basic generic example, good luck now if that works you need to figure out switches to make it happen...this scenario you need 1 toggle for on and off and 1 momentarily on for starter solinoid...basic race car setup
What I would do is disconnect everything, except battery ground to frame.
Your coil has a ground wire to kill engine when grounded to frame/battery negative.
Use a meter to determine which wire has continuity to mounting screws/flange of coil, this will be ground/kill wire when grounded out.
So with coil not ground, pull start and it should run, ground wire to negative to kill it.
Now unground coil "kill wire".
The solinoid is basically a magnet that pulls a plunger connected to a small pinion gear that will engage /"popout" to turn fly wheel.
When starter/solinoid are mounted to grounded frame, they are happy and ready to work.
The main positive wire from battery should be attached to big post on solinoid with a secondary big wire going from other big solinoid lug to starter.
It will not turn over because those lugs are not connected yet....
So if you connect a positive wire from battery to the smaller post on the solinoid, solinoid should "click" and complete circuit to engage armature to spin and pinion to pop-up and engage flywheel.
Since coil is not grounded, engine should run..
Ground coil to kill.
That is a basic generic example, good luck now if that works you need to figure out switches to make it happen...this scenario you need 1 toggle for on and off and 1 momentarily on for starter solinoid...basic race car setup
madprofessor
"Loose Cannon Creations"
The whole idea of a piece of wire (say 6' long) straight from the battery to the starter solenoid to spin it over is about the precept that twisting the key is creating a grounded circuit for that moment, likely via the switch's mounting to the metal under it, that keeps the motor from firing the spark plug and running it.
I used the idea of a 6' wire from battery-to-solenoid to keep it simple in concept. Realistically, it's assuming that you've already got a wire from the battery to the "big post" on the starter, the post that actually spins the starter. All you need is to "click" the solenoid on the starter to make it spin.
So realistically, instead of a 6' piece of wire to fire the magnetic solenoid ("click"), you can just jumper with a 6" wire from the fat wire attached to the "big post" to the post on the solenoid coil beside it to make it "click". Might even be able to bridge it with just a screwdriver.
Might not even be able to hear the click, as what will happen is the starter will start spinning the motor over. 6' wire, 6" wire, screwdriver, doesn't matter what you use to spin it, as long as you don't twist that key. Can you see here how that gets the starter spinning without you twisting the key, potentially grounding out the coil while the key's twisted? If it cranks, voila!
I used the idea of a 6' wire from battery-to-solenoid to keep it simple in concept. Realistically, it's assuming that you've already got a wire from the battery to the "big post" on the starter, the post that actually spins the starter. All you need is to "click" the solenoid on the starter to make it spin.
So realistically, instead of a 6' piece of wire to fire the magnetic solenoid ("click"), you can just jumper with a 6" wire from the fat wire attached to the "big post" to the post on the solenoid coil beside it to make it "click". Might even be able to bridge it with just a screwdriver.
Might not even be able to hear the click, as what will happen is the starter will start spinning the motor over. 6' wire, 6" wire, screwdriver, doesn't matter what you use to spin it, as long as you don't twist that key. Can you see here how that gets the starter spinning without you twisting the key, potentially grounding out the coil while the key's twisted? If it cranks, voila!
ADDPJ
New member
Good Morning! Following up. I managed to get it started with the key and figured out how to turn it off with the key. The green wire that was not hooked up was the reason the key wouldn't turn off the kart. I bolted it to the block and that fixed that. As for starting it finally with the key, my answer on that is fuzzy. It took me playing with the flywheel and fuel to get it to finally turn over...with a whole bunch of trying to start it. I had to stand on the pedal practically to get it going. Even after i got it going it would take a few turns to get it started. I turned the idle screw in a couple turns which seemed to help, I'm guessing it may have been a little lean. I tried it again this morning as cold start is my biggest issue, and it started after i held the pedal down and turned the key a few times. I still think my timing is off and that's the problem. Though now i have that compression thing in the back of my head. I do have a timing gun and it would probably be alot easier to do now that i can start it with the key and not the rope.
madprofessor
"Loose Cannon Creations"
Starters sure do beat the pullropes. If I have the choice to yank on something to have fun it won't be a rope.
Timing gun's not needed on the Predators to be accurate. Only racers too busy or cheap to get some timing keys will set timing without the exact perfection of a timing key. Type in "gokart timing advance" on ebay, order a set of timing keys for less than $10 for the set. If from "diyperformance" the # of the keys = 1.2 degrees of timing advance. (Ex: My #6 is 7.2 degrees.)
The Woodruff key (moon-shaped keystock) that your flywheel slides onto on the shaft sets it at exactly stock timing advance. The timing keys are just more pieces of that keystock that are notched out by a particular amount, allowing the flywheel to twist clockwise a little (the degrees of extra advance) before you bolt it down tight. Automatically perfect, no testing required.
On youtube type in "Gray Goat timing", he's the tech guy for OMB Warehouse videos. First one that pops up will show you an exaggerated drawing of a timing key as he explains exactly how to do it.
Timing gun's not needed on the Predators to be accurate. Only racers too busy or cheap to get some timing keys will set timing without the exact perfection of a timing key. Type in "gokart timing advance" on ebay, order a set of timing keys for less than $10 for the set. If from "diyperformance" the # of the keys = 1.2 degrees of timing advance. (Ex: My #6 is 7.2 degrees.)
The Woodruff key (moon-shaped keystock) that your flywheel slides onto on the shaft sets it at exactly stock timing advance. The timing keys are just more pieces of that keystock that are notched out by a particular amount, allowing the flywheel to twist clockwise a little (the degrees of extra advance) before you bolt it down tight. Automatically perfect, no testing required.
On youtube type in "Gray Goat timing", he's the tech guy for OMB Warehouse videos. First one that pops up will show you an exaggerated drawing of a timing key as he explains exactly how to do it.
madprofessor
"Loose Cannon Creations"
That erratic performance of your ignition switch is proof it's crapped out inside and going to fail erratically some more. Get a new one.
EDIT: Can't believe we all seem to have overlooked this very simple thing, though I can easily believe/expect that I did..............
Have you tried starting that thing using the choke? That's what it's there for, initial cold starts. Realized this simple thought when thinking about you "putting foot in it to start", which isn't a good way to crank it up.
If it doesn't start with 2 pulls, you choke it, if it starts then you ease the choke back off until it runs smooth, and then until it's off all the way.
No affront to anyone else, but me personally, all too very often I am such a dumb bass (not the fish or guitar) who doesn't see the forest for the trees. One thing to think out of the box, another altogether not to even look at what's in the box.
EDIT: Can't believe we all seem to have overlooked this very simple thing, though I can easily believe/expect that I did..............
Have you tried starting that thing using the choke? That's what it's there for, initial cold starts. Realized this simple thought when thinking about you "putting foot in it to start", which isn't a good way to crank it up.
If it doesn't start with 2 pulls, you choke it, if it starts then you ease the choke back off until it runs smooth, and then until it's off all the way.
No affront to anyone else, but me personally, all too very often I am such a dumb bass (not the fish or guitar) who doesn't see the forest for the trees. One thing to think out of the box, another altogether not to even look at what's in the box.
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ADDPJ
New member
Hi I'm really sorry for the delay in my response. Time sensitive work projects came up and those ate my time last several days. I'll look into a new switch. In regards to the choke...the engine wont run with the choke closed. Even if its been running for a while and i close it the engine will stall out. I agree with your statement, and there's got to be something wrong as to why it runs that way. I have an old flathead ford and the only time i even need to use the choke on it is if its been sitting for a while or if its under 70 here ( i live in FL so its set up for summer all the time). I'm much better with a car than this go kart..lol. That's why the timing throws me through a loop. I'm used to a distributor i guess. Ill try the choke when starting this evening and follow back. New front tires came in today so my son will be draggin me in there after dinner...lol. Ill certainly check out the timing keys which is on the list just havent gotten there yet. Least wanted to get this thing all ironed out before i went messing with it further.
madprofessor
"Loose Cannon Creations"
Motor absolutely won't run with choke (on) fully closed, shuts off the air supply to carb. It's only to increase suction on the carb to pull in extra fuel if I understand it correctly. If needed, I put choke on all the way (closed) and pull back off of it 20%. Long as motor doesn't die when turning it back off (fully open) it's good to go, not supposed to need even partial choke to keep running after a few seconds. I'm your neighbor up in Jacksonville, so I know your weather.
ADDPJ
New member
Motor runs with it off fine. Its when its on it gets cranky. I'm probably putting it full on and not realizing. Ill check this evening and follow-up. I know on my ford if i need it i pull the knob maybe a 1/4 inch, in my head on this thing i flip it one way or the other...LOL. duh....lol.
ThunderKart79
Member
The choke is only supposed to be on/closed when you are trying to start a cold engine if I am understanding what you are saying then not turning the choke on when the engine is cold is your problem since your engine is not getting cold like northern climates do you will probably have to open the choke as soon as it starts or go to half way open
Karttekk
Well-known member
Unless you have an electric fuel pump, fuel is drawn into the engine through vacuum. See if your hoses are installed correctly or there's a vacuum leak at the cylinder head. As far as the carb adjustment, run the screw or screws in all the way but not tight to not damage the needle seat. Run the screw or screws out a turn or turn and a half as a starting point. Double check your valve adjustment. Still sounds like low compression/low vacuum.