Go Back   DIY Go Kart Forum > Building Plans And Advice > Engines & Clutches

Notices

Reply
 
Thread Tools Display Modes
  #1  
Old 04-05-2019, 09:32 AM
bobby512 bobby512 is offline
Junior Member
 
Join Date: Apr 2019
Location: Palm City, Florida
Posts: 3
Thanks: 3
Thanked 1 Time in 1 Post
Default 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 !
Reply With Quote
  #2  
Old 04-05-2019, 09:47 AM
KartFab's Avatar
KartFab KartFab is offline
Senior Member
 
Join Date: Jan 2013
Location: Dallas, TX
Posts: 3,274
Thanks: 496
Thanked 1,443 Times in 1,020 Posts
Default

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.
__________________
Free Go Kart Plans https://kartfab.com Go Kart Videos https://www.youtube.com/c/KartFab
Reply With Quote
The Following User Says Thank You to KartFab For This Useful Post:
pearl111 (04-12-2019)
  #3  
Old 04-05-2019, 11:21 AM
txluke txluke is offline
Senior Member
 
Join Date: May 2011
Location: Victoria Texas
Posts: 195
Thanks: 21
Thanked 54 Times in 38 Posts
Default

I always smack it with a hammer a few times before I get crazy and try to figure out the real problem.
Reply With Quote
The Following 4 Users Say Thank You to txluke For This Useful Post:
950speed (04-05-2019), bobby512 (04-11-2019), Hellion (05-28-2019), landuse (05-27-2019)
  #4  
Old 04-05-2019, 12:26 PM
JTSpeedDemon's Avatar
JTSpeedDemon JTSpeedDemon is offline
Currently flathead-crazed
 
Join Date: Jan 2019
Location: Texas
Posts: 2,194
Thanks: 556
Thanked 294 Times in 267 Posts
Default

It could be a stuck valve. In which case take txluke's suggestion and tap the valves with a hammer.
__________________
Local Bird Engineering Nut
Reply With Quote
The Following User Says Thank You to JTSpeedDemon For This Useful Post:
bobby512 (04-11-2019)
  #5  
Old 04-05-2019, 01:14 PM
J.S.@SMS J.S.@SMS is offline
Here 8am-? Mon-Fri
 
Join Date: Sep 2018
Location: Weeki Wachee Fl.
Posts: 493
Thanks: 55
Thanked 90 Times in 79 Posts
Default

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.
Reply With Quote
The Following 3 Users Say Thank You to J.S.@SMS For This Useful Post:
bobby512 (04-11-2019), Hellion (05-28-2019), pearl111 (04-12-2019)
  #6  
Old 04-11-2019, 07:49 AM
bobby512 bobby512 is offline
Junior Member
 
Join Date: Apr 2019
Location: Palm City, Florida
Posts: 3
Thanks: 3
Thanked 1 Time in 1 Post
Default

If I spin the engine without a plug, YES, oil does squirt out. How do I remedy that ?
Reply With Quote
  #7  
Old 04-11-2019, 08:17 AM
frostyflammable's Avatar
frostyflammable frostyflammable is offline
Senior Member
 
Join Date: Oct 2016
Location: Dallas, TX
Posts: 319
Thanks: 44
Thanked 118 Times in 86 Posts
Default

Quote:
Originally Posted by bobby512 View Post
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
Reply With Quote
  #8  
Old 04-11-2019, 08:39 AM
Budget GoKart's Avatar
Budget GoKart Budget GoKart is offline
Aka a kenbar
 
Join Date: Dec 2018
Location: indiana
Posts: 902
Thanks: 14
Thanked 88 Times in 82 Posts
Default

Unless the engine was upside down then your rings might be bad?(how would i say it?)
__________________
Certified Yerfdog 3202-3203 expert.
Reply With Quote
  #9  
Old 04-11-2019, 12:24 PM
frostyflammable's Avatar
frostyflammable frostyflammable is offline
Senior Member
 
Join Date: Oct 2016
Location: Dallas, TX
Posts: 319
Thanks: 44
Thanked 118 Times in 86 Posts
Default

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
Reply With Quote
  #10  
Old 04-11-2019, 03:39 PM
Dingocat's Avatar
Dingocat Dingocat is offline
Broke
 
Join Date: Apr 2018
Location: Cleveland Ohio
Posts: 365
Thanks: 30
Thanked 73 Times in 60 Posts
Default

Quote:
Originally Posted by frostyflammable View Post
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.
Reply With Quote
  #11  
Old 04-12-2019, 12:34 PM
bobby512 bobby512 is offline
Junior Member
 
Join Date: Apr 2019
Location: Palm City, Florida
Posts: 3
Thanks: 3
Thanked 1 Time in 1 Post
Default

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 !
Reply With Quote
The Following User Says Thank You to bobby512 For This Useful Post:
landuse (05-27-2019)
  #12  
Old 04-12-2019, 12:59 PM
JTSpeedDemon's Avatar
JTSpeedDemon JTSpeedDemon is offline
Currently flathead-crazed
 
Join Date: Jan 2019
Location: Texas
Posts: 2,194
Thanks: 556
Thanked 294 Times in 267 Posts
Default

Great! Glad to know we could help!
Now time to put some performance mods on it!
P.S - Could you post some pics of the project that it's on?
__________________
Local Bird Engineering Nut
Reply With Quote
  #13  
Old 04-12-2019, 03:36 PM
J.S.@SMS J.S.@SMS is offline
Here 8am-? Mon-Fri
 
Join Date: Sep 2018
Location: Weeki Wachee Fl.
Posts: 493
Thanks: 55
Thanked 90 Times in 79 Posts
Default

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.
Reply With Quote
  #14  
Old 04-12-2019, 03:44 PM
JTSpeedDemon's Avatar
JTSpeedDemon JTSpeedDemon is offline
Currently flathead-crazed
 
Join Date: Jan 2019
Location: Texas
Posts: 2,194
Thanks: 556
Thanked 294 Times in 267 Posts
Default

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.
__________________
Local Bird Engineering Nut
Reply With Quote
  #15  
Old 04-12-2019, 04:27 PM
J.S.@SMS J.S.@SMS is offline
Here 8am-? Mon-Fri
 
Join Date: Sep 2018
Location: Weeki Wachee Fl.
Posts: 493
Thanks: 55
Thanked 90 Times in 79 Posts
Default

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.
Reply With Quote
  #16  
Old 05-27-2019, 08:51 PM
ezheimers ezheimers is offline
EZ
 
Join Date: May 2019
Location: Seattle
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default 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?
Reply With Quote
  #17  
Old 05-27-2019, 09:04 PM
Hellion's Avatar
Hellion Hellion is offline
Disc brakes'r for cowards
 
Join Date: May 2016
Location: Location: Location:
Posts: 4,626
Thanks: 1,625
Thanked 1,337 Times in 1,090 Posts
Default

Quote:
Originally Posted by ezheimers View Post
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.
__________________
"I'm just here for the gasoline"
Reply With Quote
The Following User Says Thank You to Hellion For This Useful Post:
pearl111 (05-28-2019)
  #18  
Old 05-28-2019, 06:35 AM
J.S.@SMS J.S.@SMS is offline
Here 8am-? Mon-Fri
 
Join Date: Sep 2018
Location: Weeki Wachee Fl.
Posts: 493
Thanks: 55
Thanked 90 Times in 79 Posts
Default

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.
__________________
If a picture is worth a thousand words, then how about a video?
Reply With Quote
  #19  
Old 05-28-2019, 09:35 AM
mckutzy mckutzy is offline
Senior Member
 
Join Date: May 2008
Location: bc, canada
Posts: 7,355
Thanks: 815
Thanked 1,755 Times in 1,449 Posts
Default

Potentially... Flywheel timing is off.. ie the key is sheared...
__________________
10yr+ club..... My current ride- http://www.diygokarts.com/vb/showthread.php?t=5461
Reply With Quote
  #20  
Old 05-29-2019, 10:14 AM
ezheimers ezheimers is offline
EZ
 
Join Date: May 2019
Location: Seattle
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default

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?
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 05:24 AM.