OK, so I began doing a leakdown test on the FL350 this weekend. This is the one that had 90 psi on the compression tester.


First I built a leak down tester using a 1/4" iron tee, with two barb fittings off of it, one for a blood pressure bulb and one for a piece of tubing to a magnehelic gauge, 0-150 inches of water (5.5 psi). The third end of the tee has a close nipple to a quick connect fitting in my compression tester set. I removed the shrader valve from the adapter for the compression tester and threaded into the spark plug hole, and quick connected the adapter from the tester. Tested this in a bowl of water and tightened parts until there were no leaks. The first time I pumped the motor (( Internal Combustion Engine ? )) up, it would not hold pressure.

Then, I replaced the intake boot that was ripped with new and plugged it with a PVC fitting. No leak detected with Windex. I cut a piece of 3/16" steel plate for the exhaust and attached the plate with a new exhaust gasket to the cylinder exhaust. Leaked alot, so I found an old bike inner tube and cut a couple pieces to use as a gasket. That leak stopped. Realized that the line from the motor (( Internal Combustion Engine ? )) to the fuel pump needed to be plugged, so I stuck a bolt in the end and tighened the clamp.

I pumped up to 6 psi (166 inches of water). Within about 2 minutes, I'm down to 2 psi and falling. I think I've sprayed everything I can get to on the motor (( Internal Combustion Engine ? )) - the spark plug hole, the intake that's plugged, the exhaust that's plugged, the motor-fuel pump line, the joints between the head and the cylinder and the cylinder and the base.

Is there more I need to remove, more places to spray and look for leaks, any change I need to make to my procedure? First time for me and a leak down test, so any help's appreciated. TIA

Pete

Think there is a connection with the cut intake boot and the 90 psi?

You have the Engine out of the ODY ? You need to spray the entire Engine
including the cases, I don't have my 350 manual handy but you cant spray
the crank seals because they are not accessible?

Maybe I should recheck the compression with the new boot and reeds.

Sounds like more disassembly is in order

I didn't think the motor (( Internal Combustion Engine ? )) would have to be on a bench to do this I guess.
I'll follow the procedure in the manual to get the Engine out. Crud.

Thanks.

Are

Well disassembly wasn't so bad, rechecked the compression with the new boot and it's still 90 psi, can't find the leak, so I took off the head. I'm assuming I need to do crank seals and am mustering the courage to take apart the bottom end.

Gasket was in apparently good shape, head dome was clean with a little oil on it, piston had a couple mm of carbon on it. Rings were almost flush with the lands, obviously worn.

The piston is whitish on the sides and black on the top. The only identification I could find on the top of the piston was "IN" on the intake side, no other markings. Is this the original 78.5mm piston? What are my chances of finding another one? How would I know if it's a Honda std, 0.25 or 0.5 over piston, besides measuring? No cylinder damage, so I'd rather not bore it to 80mm for a wiseco overbore if I don't have to (right?).

Also, I found a crack straight through the lower frame crossbar behind the seat and in front of the Engine, between the two bolts holding the lower belt cover, in fact the belt cover appeared to be holding things together somewhat. Guess I'll need to find a welder ... sleeve and weld would probably work best for reinforcement?

Hmm, where to start, guess I will start by asking if you have any pictures?

Any scuffing on the piston, vertical lines?

You will need to measure your cylinder to see what size it is and if it needs bored or not.
in the mean time you can contact http://www.pilotodyssey.com/PO/viewtopic.php?f=2&t=16721 and triple E 1-800-763-3762
and http://atvracing1.com/safety.htm to see what your piston options/sizes are.

Hillside Honda will probably have the best prices. 707-263-9000



You see this post? it has some info in it that might intrest you.

http://pilotodyssey.com/PO/viewtopic.php?t=1355

I've been all over that thread, and others, it's very much appreciated for a newbie like me, even pushing 40.

I figure if I DON'T find and fix any airleaks THEN I will have damage and need to bore. Right now I feel like I caught it with worn rings and no damage, looks like a mirror in the cylinder with light crosshatches.

In the meantime, that fichefinder program on Service honda's site is great, I'll print that off for part numbers and see what's available at Hillside. The fiche was revised 4/04 I believe and the std and 0.25 pistons and rings are listed as available, while only the .50 rings are available.

As far as pictures, I'll have to find the post that explains how to post them.

This help?

http://pilotodyssey.com/PO/viewtopic.php?t=19

Here's some pics.

Ody #2 has 145psi compression with a new top end not by me, reportedly has a 78.5mm piston in it, I snapped the top of the choke cable where it goes intot he carb, so that needs repairing, and it doesn't always like to go in reverse, pops out)

Ody #1 only had 90 psi

head looks fine, pretty clean and oily, gaskets intact

cylinder has no obvious gouges or scorches

came from Ody #1 nekkid almost! Took a few hours to get this far

piston looks old, there wa sa tiny drilled hole that came out to where the ring gap is turned int he photo, something missing?

clean through

The ring locater pin is missing, they usually fall out when the rings are worn
out they move more than they should then work the locater pin loose, looks like it
took a few chunks out of the side of your piston when it was taking a tour of
the inside of your Engine..

Take the rings off the piston they look anyhting like this?
http://pilotodyssey.com/badrings.htm

I don't have them off yet (yay - time to go buy another special tool!) but I can assure you they look exactly like that, oval, worn, big end gap, some deposits in the lands.

Looks like a "skate save" on this motor (( Internal Combustion Engine ? )), never would have caught it without prodding from this site.

The next steps are the hardest, finding money, finding parts, and suitable vendors to bore and hone, etc. because there's no way I can go any further unless I ID the piston and get a matching one.

Spread the rings with your thumb nails and lift them off the piston, no special
tool required...

It sounds as if you just need to replace the piston and rings. You may be able to just hone the cylinder and replace the piston and rings. Check the crank seal behind the clutch for any oil leakage (indicates oil/air leak). Also remove the flywheel and check the right side seal for the same. You don't have to dissasemble the bottom end to replace the seals. Brooks frame also cracked in the same place. Seems to be a common break on the 350. Wled and sleeve like you said will ensure a solid structure. Good luck with the rebuild. It is easier than it sounds.

I think you're right Kx, but I can't get a Honda piston, not available.

So does this mean I MUST rebore to 80 mm for the Wiseco? Where?

Why can't Wiseco just make the piston size I need? Cramps.

Justr got off the phone with Sara at Triple EEE, guess I'll send it to the experts, what do I have to tell them, if anything, about tolerances, etc etc etc?

Call wiseco for a price they will probably make you any size you want...

If you send EEE the cylinder they will take care of all the specs for you. All you will have to do is reclean it and assemble. Also send them the head as the squish band may need to be cut. I have yet to find a good shop in our area that can do a quality job on motorcycle cylinders.