Engine Trouble Engine wont start? TROUBLESHOOTING GUIDE

nope the speification only tells you what oil to use and the size of the engine (which is a lie anyway!!) its an electrical problem so you should first try the magneto off of the other engine and if that doesnt fix it then it must be the cdi.
 
If it runs for a minute before it quits, I would check the fuel flow to the carburetor. Sound as if the fuel bowl is emptying out, and not being replenished. After it sits for a while, fuel slowly trickles in and fills the bowl again - enough to run it for another minute or so. Could be a clogged screen, bad valve, etc.

Good Luck!
 
If your Happy Time engine isnt starting then work your way through this guide to identify and fix the problem. Still no hope? then just ask...
With many thanks to BoltsMissing who compiled this great troubleshooting guide.
Before Step 1. Check that the fuel petcock is on and you have fuel. Check the wires to the CDI. Make sure that they are connected. The cheap connectors come loose
1. Remove spark plug, check gap.
2. Check for spark with lead on plug and earth spark plug on cylinder head fin.

Lift the rear wheel, and give it one good hard pedal down as if you are
kick-starting a bike. If plug sparks at the tip, re-install the spark plug. (just bear in mind that I have had plugs that fire under no compression(Not in engine)but had no spark under compression(In engine)This can be a pain if you Don't know this.You could pull your hair out with this problem,new plugs are cheap!)

2a. If no spark, check Plug cap. I had to replace mine with a NGK Right Angle spark plug cap, (don't know the part No. though)
2b. Repalce lead anyway with Copper wire lead.
Check for spark again with new lead and plug cap
That's the electrical done from start of lead to end of plug tip.

If Spark, then go to Fuel.
If No Spark, go to Magneto and CDI.
But don't just replace the Magneto and CDI unless you do all the obove to.
That way you have a clean sweep out of sight out of kind type of thing of the electrics.

Fuel.

Remove Carby, AFTER Spark is all clear as explained above.
Remove fuel bowl, see if it was full or any fuel was in there.
If not, check fuel line and needle/seat where the fuel line plugs in.
There may be some grit.
If it had fuel in fuel bowl, re-fit carby.

Fuel is OK up to fuel bowl end.

Clutch adjustment, just go through the motions at the cable end. There should be no slack.
Can't say much about whats behind the clutch cover, never had one with problems ,yet.

By this time you probably flooded it trying to start and doing the other testings.

Then as last resort as I mentioned earlier,
Tow start,
and this will "flush out" the remaining cob-webs, and it ought to go.
Tow around the block or whatever until all reasonable doubt is undoubted if it still don't start. Be very careful though as this could be dangerous!

Failing a tow start, then start the inspection process again the next day, so take a break, it's only a Happy Time (HT) engine.
This time check for Head/Lower cylinder/Exhaust and Carby Gasket leaks etc.
Point is, dwelve deeper into the problem.
Tow again if all looks OK.

Remember if an engine has compression, fuel (air and petrol) and a spark then it must fire, it doesnt have a choice! ;)
 
I am smart enough to turn off the fuel petcock, but a lot of times I am too stupid to turn it on.

When I replace the CDI connections, I wire one backwards so I can't plug them in black to blue
 
Won't Start

I am having the same problem. Got spark, got gas but no go. I'm going to check the magnet next to see if it might be installed backwards. I don't know what else might be wrong. These things can drive you crazy.

The Crawler
 
hope its alright i'm posting in an older thread, but just have a few questions...


okay, so i shocked myself testing the spark plug (idiot), so i know thats working.

the clutch works great, i can feel and hear it turning the piston when i try to start the engine, so thats not the problem either.

what i have come to think is that it is a carb or throttle problem


i get the engine to turn over, hear it start firing, but as soon as i pull in the clutch it cuts out.


things i have already tried:
the fuel line is 'on' at both the tank and the carb, i used the tickler button and could see gas flow down the line (an air bubble anyhow).

PS, glad to be joining the MB community :D
 
never-mind... i managed to fix it.

for anyone that has the same problem:

use the in-line screws on the throttle cable to make sure it is tight. screw IN the idle adjustment screw, open the choke by pushing it DOWN.

I don't know which was the problem, as i did them all, but i got it goin :D

don't forget to push the primer button either.
 
check list - it can only be: FUEL/IGNITION/COMPRESSION/TIMING

Quick check list on troublesome starting..
FUEL
1) Fuel, Oil --no fuel, too much oil.
2) Fuel Pipe-blocked.
3) Fuel filter-blocked.
4) Carb stop cock/control cable-damaged, maladjusted.
5) Carb choke/control cable-damaged, maladjusted.
6) Carb needle valve - fouled, damaged, blocked
7) Carb jets- fouled, damaged, blocked
8) Blocked air filter
9) Flooding carb - Fouled needle valve
IGNITION
1) CDI wiring/connectors - connected wrong, disconnected, damaged CDI.
2) Ignition coil/pickup/connectors-damaged coil, wires, loose screws on coil.
3) Spark plug/cable/connector - Fouled, damaged plug, damaged cable or connector
4) Carb Kill switch-stuck in Kill position inside carb, wire shorted to chassis, control plunger.
COMPRESSION
1) Spark plug (Loose fit, gas escaping) ( make sure plug hole rim is clean, tighten plug with a torque wrench)
2) Cylinder Gaskets, seals.
TIMING
1) Coil gap/flywheel - loose coil mounting, damaged flywheel, coil
2) CDI UNIT-Damaged CDI, wires
3) Reed valves

Remember you can destroy your CDI by pulling off the spark plug with the engine running or even juct cranking the engine with the spark plug lead open circuit
 
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