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-   -   Predator 212cc Starting Problem (http://www.diygokarts.com/vb/showthread.php?t=40997)

bobby512 04-05-2019 10:32 AM

Predator 212cc Starting Problem
 
I recently purchased a used cart with a Predator 212cc engine. When I got it home, it started, ran fine and then I began to work on front end alignment and rust removal. I lifted the front end while working on it for two days. When I finished, I tried pull starting the engine and it seems as though the compression stopped me from starting it. I removed the spark plug and the engine crank spins freely with no restrictions or bad sounds. After reinserting the plug, it again does not let me pull start it because of what seems like compression. Being novice at this, I would appreciate all the help I can get ? Thanks in advance !

KartFab 04-05-2019 10:47 AM

go down to an auto parts store and pick up some feeler gauges. You will need these to check valve lash. You remove the valve cover ( 4 bolts) and turn the engine over to TOP DEAD CENTER or a smidge past top dead center on the COMPRESSION STROKE. Then check valve lash. Should be about.002"-.006" ISH. See users manual. If you have too much lash, it could cause this.

If you have fuel leaking into the combusiton chamber, it could cause this.
If you have spun the flywheel, and your timing is off, it could cause this.
If your spark plug is fouled, it could cause this.
If your magneto is going bad, it could cause this.
If you dont pull the pull cord hard, it may feel like you cant turn it over.
Could be a number of other things, but id check valve lash and make sure your carb is not leaking.

Who knows, maybe you got oil in the combustion chamber, and you just need to remove the plug again and yank that pull start a bunch to launch the oil out of the spark plug hole, and then you wont get it locking up.

txluke 04-05-2019 12:21 PM

I always smack it with a hammer a few times before I get crazy and try to figure out the real problem.

JTSpeedDemon 04-05-2019 01:26 PM

It could be a stuck valve. In which case take txluke's suggestion and tap the valves with a hammer.

J.S.@SMS 04-05-2019 02:14 PM

About the best, and easiest way to set valve lash is to:
1. remove the plug
2. remove the valve cover
3. turn the engine over until the exhaust valve opens, and set intake valve lash to .006"
4. turn engine over until intake valve opens, and set exhaust valve lash to .008"

And definitely make sure that there isn't a stuck valve.

And a quick stupid question. If the plug is out, and you pull the engine over fast, does any liquid spray out? If so than the engine may be hydro locking, and because it is extremely difficult (though not impossible) to compress a liquid.

bobby512 04-11-2019 08:49 AM

If I spin the engine without a plug, YES, oil does squirt out. How do I remedy that ?

frostyflammable 04-11-2019 09:17 AM

Quote:

Originally Posted by bobby512 (Post 519767)
If I spin the engine without a plug, YES, oil does squirt out. How do I remedy that ?

Keep spinning the engine until all the oil has come out. There should be no puddles of oil on top of the piston.

--Daniel

Budget GoKart 04-11-2019 09:39 AM

Unless the engine was upside down then your rings might be bad?(how would i say it?)

frostyflammable 04-11-2019 01:24 PM

The rings (as far as I understand) do not seal completely, there is a small amount of space from where the rings would completely seal so it could technically work its way between the rings. It is IMO very likely that if the engine was angled enough for the oil to go past the rings it would end up on top of the piston.

Now when I do a front end alignment I lift the front a few inches this would have had to been high enough for the oil to go past the piston.

--Daniel

Dingocat 04-11-2019 04:39 PM

Quote:

Originally Posted by frostyflammable (Post 519821)
The rings (as far as I understand) do not seal completely, there is a small amount of space from where the rings would completely seal so it could technically work its way between the rings. It is IMO very likely that if the engine was angled enough for the oil to go past the rings it would end up on top of the piston.

My grandparents brought a dingo up to me ~500mi and it sat upside down the whole way, cylinder was full with oil when I got it, after pulled the plug and spun it over a bit good to go but smokey startup. Burning off the extra oil left.

bobby512 04-12-2019 01:34 PM

Thanks again to all for all the good advice. I put a feeler gauge on the lifters, adjusted to correct specs, spun the crank until it stop spitting oil and it started right up and has been running fine !

JTSpeedDemon 04-12-2019 01:59 PM

Great! Glad to know we could help! :thumbsup:
Now time to put some performance mods on it!
P.S - Could you post some pics of the project that it's on?

J.S.@SMS 04-12-2019 04:36 PM

Not every engine needs performance mods. Quite frankly, I wouldn't trust my go kart with any more power than the stock 212. Of course not every kart breaks the 30 mph barrier with 22" rear tires, and a rather sketchy front end. Straight, its fine, but when at top speed, a little touch in either direction and you're in the next lane before you can blink.

JTSpeedDemon 04-12-2019 04:44 PM

Mine will probably do the same thing at high speed.
Zero caster.
Homemade spindles.
Chunky steering.
What could go wrong?
At least I'm planning for torque, not a screamer.

J.S.@SMS 04-12-2019 05:27 PM

My kart doesn't really have a chunky steering, it just (despite my best efforts) has a really bad alignment problem. No matter what I do, It doesnt like it. I've tried varying degrees of toe in and some toe out. The one thing that I haven't tried is no toe. But, my kart does have stock spindles. But it also does not have any caster. Also, the only more down gearing that I can do, without drastically changing the setup is, swapping the 9t TC sprocket for an 8t.

But once I sort out the front end, you can bet that it'll get at least a stage 1 kit, and a shaved head.

ezheimers 05-27-2019 09:51 PM

snaps starter cord?
 
I've a Predator 212 Hemi that just slams the starter cord out of your hand?
Doesn't want to start but will... But beats your fingers up because when starting it - it just slams the handle and whams your fingers...
What's wrong here?

Hellion 05-27-2019 10:04 PM

Quote:

Originally Posted by ezheimers (Post 523704)
Doesn't want to start but will... But beats your fingers up because when starting it - it just slams the handle and whams your fingers...
What's wrong here?

Faulty starting procedure.

These small engines have high compression. What you need to do is:
A. Pull the starter cord slowly out of the housing until you feel resistance. This will be the compression stroke (piston approaching top dead center)

B. Stop pulling and let the cord retract all the way back in
C. Give 'er a hard yank
D. Engine should start

If you don't pull on (and through) the compression stroke, the engine has a tendency to rebound or bounce off the compression and yank the cord out of your hand.


Is your engine modded (molested/tinkered with) or fresh out of the box?

EDIT: I forgot these engines have a compression release built into the camshaft.
You could have excessive valve lash.

J.S.@SMS 05-28-2019 07:35 AM

It could be the valve lash. The proper setting is .006 intake and .008 exhaust from what I remember. And I wouldn't exactly call 8.5:1 compression high.

mckutzy 05-28-2019 10:35 AM

Potentially... Flywheel timing is off.. ie the key is sheared...

ezheimers 05-29-2019 11:14 AM

Does it pull or slam the starter cord out of your hand?

---------- Post added at 09:14 AM ---------- Previous post was at 09:06 AM ----------

Box stock... Gov removed... Just slams your hand when starting?


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