Ouch! HS 49cc with broken exhaust valve

[scotto-]

I recently bought two 49cc Honda clone engines used......one was fine, the other had a broken exhaust valve. Luckily for me, the only damage is the exhaust valve itself and a slightly bent ex. push rod. Other than that this engine is in extremely fine shape, here's some pics......

 

[The_Aleman]

Whoah! Wonder how that happened? At least there's no serious damage, good thing parts for the HS are so cheap!

 

[Ibedayank]

only seen that type of damage when somebody stuffs something into the cylinder or SEVERLY floods a motor....

 

[scotto-]

It looks like the valve came off the keeper somehow......it would have snapped where it did after dropping into the combustion chamber. Yeah, very lucky the damage was minimal......and yes these parts are cheap!

 

[scotto-]

Whoah! Wonder how that happened? At least there's no serious damage, good thing parts for the HS are so cheap!

OK, here's what happened after inspecting the failure. It looks to be a wornout exhaust valve keeper was the culprit. The valve dropped into the cylinder (cumbustion chamber) and nearly reeked havoc on the engine. I ordered a new exhaust valve (and an intake valve as well for good measure), did a little port work and put it all back together.

Went to start it up and no go. Put a little ether (starting fluid) to it and it started right up. Then I put the propane to it and the same thing.....it ran fine. So what does this tell you? It tells you your carburetor is not doing it's job. I pulled the float bowl off, pulled the main jet and emulsion tube and low and behold, found the problem.

The problem; a clogged main jet. Clogged solid with some yellow powdery sunstance. The solution; had to re-drill the main jet. The result; engine runs like a champ now!

It sure is rewarding to know how to do this stuff and it saves a heck of alot of money as the end result. Let's ride!

 

[azbill]

I love it when a plan comes together

 

[The_Aleman]

That valve keeper was probably cast by the same guy who peed in the "sugar" bowl that the carb jet was dropped in lol

 

[scotto-]

That valve keeper was probably cast by the same guy who peed in the "sugar" bowl that the carb jet was dropped in lol

Yeah, prolly Those keepers are really hardened, makes me wonder why it wore out so quickly. The guy I bought it from didn't even know it dropped a valve......he say's "it doesn't turn over when you pull the starter" as he's pulling on the starter Can't believe nothing else was damaged in the event.....still would have been a cheap fix.

Here is a short vid of it running today......nice gearbox huh?


http://youtu.be/9l7FRE8n_ZE

 

[GearNut]

Looking good. Sounding good too!
So, is it a Hoot single row chain or the better duplex chain box?
Why do I imagine you stuffing this into a modded 20" BMX frame?

 

[scotto-]

Looking good. Sounding good too!
So, is it a Hoot single row chain or the better duplex chain box?
Why do I imagine you stuffing this into a modded 20" BMX frame?

Thanks Dan, it's a single row box. You only imagine stuff like that cuz I can.....and I will

You up for a ride soon? You know how to reach me.