Engine Trouble spark plug shot out of head

[nishikidrift]

if hes using that isnt there a chance of a blowout?

 

[butre]

What is the thinnest I should go for head material without shaving the head to gain compression? What grit sand paper should I use for planing? It looks like this weekend ill be getting to get this done... i just pulled my head and i think my cylinder is flooded so, I'm for the night in going to leave the head off so it can evaporate and dry out.

p.s. yes I'm a neophyte.

start at 240 and work your way up to 1500. that's what I used to do before I got my milling machine.

 

[crassius]

all this is nice, I suppose, but if the gasket doesn't show oil residue around it, then it isn't leaking and that means working on it won't make the bike start running

if it won't start & no oil is around head gasket, I'd put my efforts elsewhere to find the problem

 

[KCvale]

I fixed my engine air leak, went for a ride (forgot to tighten plug) and the spark plug vibrated loose and shot out threads are fine. now the engine wont start. I have spark and fuel any ideas?i have drained the bowl and made laps trying to start it.

It sounds like your crankcase is full of raw fuel.
Understandable when it lost compression and couldn't fire.

Try this:

1. Turn off the fuel and take the plug out.
2.Ppedal it up and down the street with the clutch released, throttle closed, and blow it all out the spark plug hole.
It's easy, no compression.

3. The head and gasket.
Before you start spending money on head milling and gaskets, do you have a torque wrench to tighten the head nuts properly when you put the head back on?

You simply don't want to do this by 'feel', you need a torque wrench and a socket to do it right.

If you don't have one borrow one or ride it up to any kind of repair place, it's a crucial tool every place that works on engines has.

Or really, just buy a torque wrench for your 2-stroke.
Harbor Freight has a cheapie for $22 that is better than nothing.
http://www.harborfreight.com/3-8-eighth-inch-drive-click-type-torque-wrench-807.html

Most manuals call for ~10 Foot Pounds torque for a 66cc.
I start with 5# for each nut in an X pattern at a time, then go another 5# for each nut in the X pattern until I get to 20# for each nut.

I'd stop at 15# if you have the cheapest of cheap kits that have weak studs though, and just don't worry about it if she fire up.

What is important is the head nuts are tightened up a bit at a time like lug nuts on a car, but to the same amount of tightness, at it takes a torque wrench to do that.

 

[nishikidrift]

I'm going to do all these things and more to be sure that i get it right. I havent taken my head off yet but plan on making a new copper gasket soon. I pedaled the bike and went one step farther and took of the gas tank carb an flipped the bike upside down for the night letting it drain. tomorrow Im going to try to start it.

 

[nishikidrift]

I got nothing. what if I bought a hotter plug like ngk bp4hs to try and force it to fire?

 

[crassius]

If the plug you have is good, then hotter won't help - did you try a compression check? Places like auto-zone and other auto parts stores often loan out tools like a compression tester for free..

 

[nishikidrift]

Crassius, the compression is fine, thank you for the idea. just for the heck of it i turned the head 180 degrees and tried to start it and got some results although it didn't start it did pop once or twice each lap,this is an improvement form absolutely nothing. I checked the timing and that was fine sitting at 1 o'clock.

 

[crassius]

a bad CDI can sometimes make a bit of popping

 

[nishikidrift]

ok will trade out thanks. the poping is an imperovment from getting nothing at all.