did leak down/pressure test - small crank seal leak on drive clutch side - no other leaks.\
we will install new crank bearings and seals
will lap head.

pulled the cylinder most everything looked ok.
top ring of piston was stuck in the groove on the exhaust port side right at the bridge.
Kyle said it showed to have 10mm piston/cylinder clearence.
we will bore and install new wiesco piston kit (i know i know Honda)
we could see where one of the ring opening had been nicking both the top and bottom edge of one of the ports and i am probably lucky that it didnt hang up on the port and cause a lot of problems.
we will go back with a different piston - one made for the fl250 and we will either cut up the skirt or boost port the piston .

we will clean up the intake and exhaust areas matching up things. we will also boost port the cylinder.

kyle wants to bore out the carb - maybe get approx 1 to 1.5mm increase.

more to come

OMO
Curtis

10mm????????

you know what i meant :) .010

Any detail pics?

not yet but i will get some monday and post

this was really a preventative tear down - but glad we did it

OMO

Boost port cylinder?? Does this mean the 350 guys need to watch out?? LOL...Have fun with your rebuild!

we will see :)

here are a few pics

How many hours you have on that piston? Looks like a lot, but hard to tell from pics.

Lots of carbon build up in the roofs of the transfers and I think I see a carbon trail above the forward transfer on the cylinder wall maybe the pipe is all wrong for this cylinder and the returning pulse wave is too soon, not enough blow down time? The extra carbon in the cylinder will account for accelerated wear.


OMO do you ride extended periods of time at one throttle position?

no - in and out of throttle all the time ?

Ok I thought so, talk to your buddy about the pipe your running see what he thinks..

2.5 - 3 years - no real idea of hours but 20 - 30 maybe

parts are in
split case seal on clutch side was leaking a little - say that during pressure testing
bearing on clutch side had rust on seal side - good thing we decided to do the bottom end too
will hone cylinder and fit piston - match up the intake and exhaust then take cylinder and case halfs to be vatted

will post some pics of cylinder clean up and boost porting

OMO
curtis

PARTS ARE IN! I like those three words. I just got my rings in. I am re-ringing my 350, and since my cylinder was removed from the bottom, I decided to pull the starter and check for oil in it because it was cranking slow even with new battery. I was amazed at how much oil had made its way into the starter, looked like some one dunked it into a gallon of oil. I think oil was in the starter before i did the "oil in starter mod". Ill be intalling a new crank case seal next to clutch, among other goodies...New front Works shocks,new duster clutch, new seat with sides and Im fabbing a skid plate/heat shield for it, reed spacer amongst other parts, I hope its ready by fall and likewise with your project.

Good to see you making progress. would you share some info on boost porting like what your doing and what it will help and what it effects. Do you clearence the bridge before honing to size or afterwards. What a good clearence for the cr piston. By chance did ever look at a moolson for the application. If all elese fails maybe discuss at dunes over cold one. I like to learn. Thanks Rich. P.S. We all like pics.

hey Rich i will post pics of the cylinder and piston bootport and what info i have when we get started on the top end.

here are some pics of the bottom end. should get started on it tomorrow.

OMO
Curtis

Thanks for the pics. Nothing like working with clean parts. Are you micing the case and bearing to see how tight the bottom is. If so maybe share the info.

Good idea I have seen plenty of the 250 cases where the bearing pockets were slightly egg shape and no longer held the bearings in place tight, some were still usable by applying some locktite to the outer races, you can see the carbon trail extended all the way to the bottom of the crank cases and behind the bearings...

yes Kyle micked the case and bearings but i do not have any figures. we got the bottom end back together and the piston boost ported and dressed out. i will post pictures tonight.

the crank looked good except for a small rust ring right where the seal is on the clutch side. we adjusted the seal to fit where the rust ring is in between the two seal areas of the Honda seal. we will pressure test and hope for the best.

Rich - from what i have been told the boost port of the piston is use because of the change from a piston ported motor (( Internal Combustion Engine ? )) to one with a reedcage. this allows the motor (( Internal Combustion Engine ? )) to continue sucking air/gas when the stock FL250 piston shuts off the intake. maybe someone else can explain it in more detail.

I am not a motor (( Internal Combustion Engine ? )) builder but i am learning. the information i have is only a repeat of what i have been told from people i trust.

OMO
curtis

more pics

Here we go

Here we go

Well!!!!!!!!!!

Wonder how long that seizco piston's gonna last.......

Given any thought to how out of balance it will be when you remove that much material?