Hey i'm 32 going on 16 haha...finally getting my fun toys I wanted 16 years ago!
Anyhow, picked up a FL350 that was advertised here. It doesn't run, seems to have low compression but knew that going into it. Has a DG exhaust system, larger carb, water cooled head, new works shocks. Anyhow, i'm going to pull the head on this and see where to start, can anyone ID this head? Will a stock FL350 head gasket work? He said he was running it in a desert race, and it just stopped, turns over ok so it's not locked up. I suspect a burned piston, but not sure, as i'm not very familar with the 350. If anyone out ther would like to mentor me through this i'd appreciate it, things to watch for, etc etc...

I would pressure test the Engine before you remove the head to see if it has a air leak that might be part of the problem it has, dunno who made the head but I bet you can tell what gasket it uses when you remove it from the Engine.

You will need to remove the carb and exhaust to pressure test, you need to block the intake and exhaust then pressurize the Engine usually through the pulse tube that runs to the fuel pump, you wont want to exceed 10 psi and will want to watch the pressure to see if it drops and if it does log how much in what amount of time, 8 to 10 psi for 1/2 hr is a good thing.

When you remove the exhaust you can probably see the condition of the piston and rings with a flash light.

Let us know what you find.

Where you from?

I'm in Oklahoma, just south of OKC. Small town called Tuttle. Thanks for the tip. I bought a leak down tester on ebay the other day, motion pro I think it was has the plugs and pump up bulb, I'll check it when it gets here. Initially I was thinking he may have leaned it out, he said it was running like crazy and no problems. One thing that does lead me to think about a air leak is that the area next to the carb/block is coated in oily gunk and it is freash, fuel valve is off as well, so it isnt' from transport the area is pretty dirty so it is old oil.

Compression check shows 30psi, it did hold the 30psi for over 5min, i finally relieved. I'm hoping it is a simple thing like piston ring and the bottom end is still ok.

Well looks like it is in pretty good shape.fuel is gravity fed with what looks like a flatside makuni carb of at least 32mm (should be anyway that's what stock size was).The head looks to be a Kustom kraft style but is a little different than mine,in that it has the lower hose coupling on the base (body) of the head instead of the lower section of the top plate.Mine has both on the top plate and my top plate is different too,yours may be a Rand head? shouldn't matter much as the bolt pattern should be the same but bore size might be a tad different.Be carefull with removing the top plate so you don't damage the o-rings.the stock honda gasket should work fine.they come with four thin layers to the full gasket and can be seperated if need be to run a little higher compression ratio if you wanted to.You probably should just run the full stock gasket for a stock setup but can run it with only one thin layer as long as you have proper clearance between the piston and head (squish measurement).
yes it would definetly be a good idea to do the pressure test first.Pull the seat and remove the pipe and intake and get a good look at both the piston and reed set.A quick compression test may be a good idea to before dismantiling the motor (( Internal Combustion Engine ? )) for the pressure test.Look into Hosers tech pages for the pressure test procedures.
It's a possibility the reed set went south on the motor (( Internal Combustion Engine ? )) ,a hole in the piston top or rings gone bad from a break in w/synthetic oil ? let us know what you come up with on the compression and leakdown test and what the reeds and piston look like.
Take some pics and post them if you can.

well i guess my reply was to long winded,you beat me too it.30lbs isnt good at all.
should be 140-155.


any grinding noise from the cylinder area when it's turned over ?
air leaks are a bad thing,your going to have to track them all down,seals,intake,cylinder base,case halves,pulse line etc. need to be checked.If the piston skirt and cylinder don't look to bad after teardown,you will probaly be ok with the bottom end with the exception of crank seals.
The recoil and flywheel etc. will have to be removed for a good look into the right side seal.

Thanks for the great help on the head ID on my 350. I took some pics of the piston just a bit ago. Sort of hard to get a clear one, but I think these tell the story as I see them. Also have included a picture of the "extra" cooling fans, is this a normal mod that you see here?
The pison is scored just to the right of the exhaust port center, the carb side of the cylinder looked ok, but hard to tell from an exhaust port inspection. Any reason to do a leak down at this point? I'm thinking of pulling the motor (( Internal Combustion Engine ? )), and doing a top end rebuild and checking the bottom end at that time. Is this a good path? Any thoughts to what caused the failure?
Since I don't know the history real well on this motor (( Internal Combustion Engine ? )), I want to do it so that it will be reliable and not just fix the one thing wrong now, then find another thing a few months later.

Thanks,
Charlie

Here are somemore pics, I am guessing in my limited 2stroke knowledge that this is a ring failure. Any thoughts on cause? Where should I send for boring and such?

I brighten up your pics a bit and drew arrows to your cooling fans, if they move a
good amount of air they are a good mod for trail riding when you have low air
flow.

The idea of pressure testing the Engine is to see if you have a leak in the bottom
end, cases or seals, now if you install the new top end then pressure test and
find the crank case is leaking you assembled the top end for nothing, if you remove
the Engine and pressure test like you said you can reuse the old gaskets for the
pressure test just spray around them to make sure they are not leaking when you
test, they should seal fine.

The pictures are too dark, I can't really see maybe try with more light and make sure we can see as much of the cylinder as possible, even 4 pics from 4 sides so we can see exhaust port , intake, the left and right sides. you going to have to pull the cylinder any way so you might as well do it now.

Don't force anything or pry apart with screw drivers and mess up a mating/gasket surface. If you must hit the cylinder to get it loose use a wood block or no bounce soft mallet.

Wiesco was pretty cheap on bore job last I heard i think $40. , Lots of guys use EEE, I was lucky to found another local guy who seems to do pretty good work. Lots of times many local dealers will send their bore and crank work to a local guy, you may get lucky and find the hook! $40. is a very fair price, $50. is ok but much more and your getting screwed.


if you do pull your cylinder take a rubber band or two and secure the rod, do not let it flop around and don't put any sideways pressure on it

Great stuff Hare, here is a pic on supporting the rod with rubber bands...