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No start after top end build

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My buddy brought me his yz 250 after he did a top end and it didnt start. Its getting spark, fuel through the fuel line, electric is plugged in. After smelling the plug it seems like its not getting fuel to the plug. I flipped the reeds because i could see light through them and a new set is on the way. Also planing to clean the carb but after looking at the throttle valve it looked really clean. It was running 2 weeks ago. Ive also done an ether shot in the plug hole to no avail. Its his first bike and he sprayed wd40 in the cylinder and did not hone it. This is the first 2 stroke ive worked on could it be a timing issue? Where should i go with this?

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If it was only a top end the timing is fine.

Now if he has way to much WD-40 inside the crank he is loaded up. Wide open throttle and kick it many times. When it fires, feather the throttle until it's cleand out. 

Edited by 2 STOKE YZ DOC
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Ok havnt tried WOT yet. Ill try that tomorrow. You think the wd40 is fouling the plug? It is greasy when i take out but doesnt smell like gas.

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Just now, dirtbikedaddy said:

Ok havnt tried WOT yet. Ill try that tomorrow. You think the wd40 is fouling the plug? It is greasy when i take out but doesnt smell like gas.

You might need another plug after you get it running, or even before. But a top end is a simple repair, and to much oil on assembley or anything really can load it up and give it a hard time to fire. 

Good spark, and fuel is all it needs to get up and go. So if the fuel is flowing, the bike has only been down for two weeks, there is no reason it shouldn't fire up. 

2 minutes ago, dirtbikedaddy said:

Yeah it feels normal to me. He did reuse some of the gaskets so could be a leak i suppose.

????

What gaskets did he re-use?

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Just now, dirtbikedaddy said:


Whats the best way to get that crap out? Kick it without the plug in?

Plug out and pipe off, and kick the piss out of it. 

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Just now, Hudson Charlton said:


In other words NEVER reuse gaskets.

Well, if you just put the top end on, and then pulled it off after a 2 hour run, you "can" get away with it. It's just not a recommendation, or something I would do.  

1 minute ago, dirtbikedaddy said:

O ring on the head and water pump. I believe the base was new

Bad choice, the right case gasket is OK, the O-rings is a no-no, water pump cover doesn't need to be removed.  

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3 minutes ago, Hudson Charlton said:

I kicked and kicked a cr after a top end. Suddenly it fires up and just screamed. Crank seals were leaking.

It's always depressing when a fresh rebuild messes something up.

Every engine I do a top end on gets all new seals also. It's just one of them things you want to do for an airtight crank.

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