Need advice

[DAN]

So today I started opening the head and I realized you cant take out the two bolts because they bump into the frame (that really sucks) but from what I lifted and saw there is a bunch of rust and it doesn't look like it kissed the valves (the owner said it could've) So how to I properly get rid of the rust , can I just use WD - 40 and scotch Brite ?

 

[beastlywarrior228]

Where is the rust? I usually shift the head forward a bit and pull the bolts out in front of the stem.

 

[DAN]

On top of the piston and bottom of head where the valves are

I'll go try your strategy right now thanks

 

[PineyPower]

Picture says 1000 words but if it is what I imagine a scotch Brite pad will get any minor rust off the cylender wall. If there's any pitting you can feel with a fingernail it needs more attention with a honing stone.
You should pull the piston and clean the rings and the grooves they sit in during all this.
Honestly if anything is messed up it's a good excuse to do a big bore. You can get a larger piston from wiesco or je for about 200$ and have the jug punched out to match it for another 100 or so

 

[PineyPower]

And honestly it's only a few more bolts to pull the engine, for what it's worth. It's alot easier to inspect and work on it if it's on the work bench, especially if it turns out yoy have to split the case

 

[beastlywarrior228]

I would do a fresh top end and get the head cleaned if it's rusty.

 

[DAN]

How do i clean the head? I saw rust inside the engine when I took off the carb thanks

 

[DAN]

Also it already had some type of high compression piston
I kind want to keep the piston and change out the rings
And when I clean the cylinder of of rust is it possible I could cause damage like uneven surfaces ?

 

[DAN]

Here are some photos I already cleaned the rust off of the valves and I think it looks nice also why is one looking flaky is that okay? the piston is in much better condition in person and how do I clean that rust in the first photo inside the head?

 

[00.warrior350]

Here are some photos I already cleaned the rust off of the valves and I think it looks nice also why is one looking flaky is that okay? the piston is in much better condition in person and how do I clean that rust in the first photo inside the head?

I would hope the flakey bit is normal because that's how mine is

 

[beastlywarrior228]

The cylinder doesn't look great. Looks like a lot of carbon buildup in the exhaust port.

 

[DAN]

How can I fix that?
And get rid of the rust at the same time?

 

[PineyPower]

Ok, I see now heres what I recommend, bare minimum.
Pull the jug off and get the piston out, get the rings off the piston and clean it real nice like, especially the grooves. Get a new set of rings. Give the cylender a quick hit with the honing stones and make sure it gets an even finish. If there's any defect after just replace the jug.
Pull the valves out of the head and clean the rust off the stem, inspect them for damage. Any pits or grooves in the stem after cleaning, or the heads not straight when you sping them in a drill means replace them. In any case, with the valve out of the way yoy can clean the ports nicely.
Lap the valves, new or old, when you install them and in the process check for pits cracks or other damage in the valve seat.

 

[DAN]

Thanks but I have a problem I turned the engine once over and it wont go any more for some reason my brother said the chain could've got stuck is there any other possibilities?

 

[PineyPower]

If you've never done anything like this before, you may need a few tools. A valve spring compressor is nice but you can improvise one with a big c clamp and an old socket with a groove cut out of it. You can get a honing stone that fits in a regular drill too from most auto parts stores

 

[DAN]

My brother rebuilded a kx250 before he has tools like a cylinder honing tool and more

 

[PineyPower]

There's a good chance the timing chain got all caught up the way you have it, you may as well pull the stator and flywheel off, you'll need it out of the way when you do the timing chain anyway.

 

[DAN]

I'm probably going to do that
Do you know if its better to keep the crappy OEM carb and rebuild it or to get a new carb?
Also what are people saying about yfz450 carbs on warriors?

 

[beastlywarrior228]

I run a yfz450 carb on my warrior and love it. It wasn't cheap swap though.

 

[PineyPower]

Ditto. Unless you have alot of other work done just rebuild the stocker