Tecumseh OHH60 Problem

[Dirtracingchamp]

Hey guys! I have a Murray Explorer go kart with a Tecumseh OHH60 power sport. After replacing the blower housing, recoil start, and carburetor, the motor will not start. What should I do?

 

[Texan]

Do you have spark? Make sure the kill switch is working correctly.

 

[ezcome-ezgo]

Does it have a choke, or primer bulb on the carb?

 

[Nosandwich]

Blower housing?

There's a wire that comes off the coil and is supposed to be connected to a plastic square on the outside of the "Blower housing "...ie..shroud. If that wire touches anywhere else, it's basically a continuous kill switch.

In other words, it needs to be isolated. It's a green wire.

 

[Randy H]

Blower Housing

 

[Nosandwich]

I stand corrected, still...cut the green wire!

Seriously, check for spark. That secondary wire is meant for kill switches, and if it's against metal... well....

If you have spark, we'll explore elsewhere.

 

[bob58o]

Blower Housing, fan shroud, ...

I like blower housing. I'm not a fan of the word shroud.

I asked where the Semantics Division was and the lady at the desk told me it was more of a Department. Still don't know where it is.

 

[Nosandwich]

Blower Housing, fan shroud, ...

I like blower housing. I'm not a fan of the word shroud.

I asked where the Semantics Division was and the lady at the desk told me it was more of a Department. Still don't know where it is.

You would. I'm more partial to shrouds than "blowers"...but to each his own I guess! But I'm still betting it's that secondary kill switch wire.

"Cut the blue wire"...."They're all blue wires!"

 

[ezcome-ezgo]

Air circulating shield, or ACS. Invented by Dr. P.O. Teckasheema in 1893 while he was working for the Wisconsin Engine Company of Moline IL.

 

[Dirtracingchamp]

It has a choke style carb

---------- Post added at 07:21 AM ---------- Previous post was at 07:17 AM ----------

Blower housing is what I call it. It can be called a fan shroud

---------- Post added at 07:22 AM ---------- Previous post was at 07:21 AM ----------

Is the secondary kill switch wire the green wire on the housing?

---------- Post added at 07:24 AM ---------- Previous post was at 07:22 AM ----------

I do have spark

 

[Texan]

Do you have compression?

 

[Dirtracingchamp]

Yeah

 

[bob58o]

You have spark.
You have compression.

You need air.
You need fuel.
You need the spark to happen at the right time.

Remove the airbox.
Open up the throttle.
Spray carb cleaner or starting fluid into the intake.
1 or 2 seconds of spray straight into the carb/cylinder head.
Try to start the engine right away.
Tell us what happens.
Does it try to start?
Does it run for a few seconds, then die?
Does it not even try to start?

 

[Dirtracingchamp]

It doesn't even try to start. Thanks for suggesting this though.

 

[Texan]

Your flywheel key may be sheared.

 

[Karttekk]

To keep it as simple as possible, pull the shroud back off and look for a wire similar to where the arrow is in the attached image. I would carefully extend that wire with a wire nut or heat shrink an extension on it and run it up to a kill switch on the steering column. Pick up a basic kill switch, mount it to the steering column. Connect the lead to your extension you put on the coil. Flip it to ON to start, OFF to kill the engine. If there are two wires on lugs coming off the coil, remove one. Eliminate any extra wires or shroud switches temporarily. This is the basic setup on a kart with that type of ignition. Not familiar with that particular engine but the theory is similar to most of them. If the coil and plug are good, fuel is getting to the combustion chamber and you have decent compression, it should start. No reason it shouldn't.

Thanks

 

[Karttekk]

Unless of course what Texan said, if the flywheel key is sheared it won't start. The timing and spark will be way off and never fire. If the kill switch test still doesn't help pull the flywheel off & check the key.

 

[Nosandwich]

What he said ^^^^ The green wire outside the blower housing is normally installed into a plastic square to isolate it from metal contact.

But if you have spark, compression, and it doesn't do anything when you spray something in the carb throat (personally, I prefer carb or brake cleaner for that test, they last a little bit longer than ether, and burn well on their own.) But, it almost HAS to be timing.

 

[bob58o]

If you have spark and compression and it still won't start on carb cleaner, you have a sheared key.
The timing is off so the spark is not happening when it needs to.

First, check the coil gap, if it is ok then....
Pull the flywheel off and show us the broken key.

 

[Girl-Trapped]

Did you ever get resolution on this? What about a little more history before you replaced the items--was it working consistently before?

I ask because I have this motor on my Yerf Dog, and have been down carburetor row before--cleaning and rebuilding it, not replacing it. Assuming it had been running before, you probably have plenty of carb adjustments to make regarding throttle & idle linkages or butterfly crack-screw, but at least if those were your problems, it should at least sound like it wanted to start.

Along the lines of troubleshooting if it has not been running yet, all the previously mentioned ideas are good. In addition, the problem I ran into most recently was that my valve rockers were so loose that it gave the same not-even-trying-to-start symptoms that an improperly grounded wire or sheared flywheel key will give you. And bonus tip--removing and fixing valve lash is EASIER than dealing with the flywheel key! Just be careful with the valve gasket so it doesn't break when you remove the cover.

After correcting my valve lash to the correct .004 specs (or a sheet of notebook paper) my engine fired right up and my flywheel key was not sheared.