Honda Pilot Top End Inspection-Rebuild By hoser..

A top end inspection or rebuild is serious task, it is not something to be rushed and 
nothing can be over looked, if you don't have patience don't even think about doing 
it yourself, I would never consider doing one to one of my machines any place but in 
my shop or in a enclosed trailer that was dust free. (that is why you see always see 
a back up machine on my trailer)

To start with buy a service manual and read it before attempting to make repairs, then 
order all the gaskets you will need before hand, if you get the Pilot-Odyssey discount 
from Hillside Honda 707-263-9000 you need to allow a week before you will get your parts, 
they are slow but you wont beat their prices unless you own a Honda shop.

I like to have plenty of paper towels handy to cover openings and to keep my hands 
clean, paper towels are probably not the best choice because they are not lint free but 
the lint they give off is not as destructive as the lint from a cloth towel, I also have plenty 
of zip loc sandwich bags and a few cans of carburetor cleaner and a hand full of rubber bands.
Before you start wrenching you will want to pressure test the engine, some examples 
can be found here. My Pilot Rebuild and Pressure testing a 2 cycle engine.

When removing the head and cylinder forget all about using anything to pry it apart
tap it with a soft nylon or rubber hammer if you get brutal wile removing the cylinder 
or head expect a large bill to replace the damaged parts, most heads will pop right off
with just a few blows of the soft face hammer, I have spent a few hours getting cylinders
off and never did any damage to the cases or cylinder in the process, if you cant get 
the cylinder off email me pilot400@mchsi.com and tell me what you have done so far and I 
will walk you through getting it off without damage.

NEVER remove gaskets with anything that requires power! (air or electric) unless you 
have a ton of cash to spend, sanders, power scrapers and rotary tools with "gasket remover
pads" do enough damage to steel and cast iron they have no place being used on a 
aluminum surface, do it by hand and take your time, I use a single edge razor
blade and pocket knife but be careful if you scratch the machined mating surfaces you 
could create a costly leak the will rear its ugly head in the future.

Note: expect to spend 2 hrs removing gaskets from the cylinder, head, crank case and
reed cage, if you get it done faster you probably did a poor job or screwed something up, 
trust me I have done the gasket scraping thing on Pilots about 10 times now :-)

Once you get your top end apart you can remove most of the carbon from the head, piston
and rings by putting them in a coffee can and spraying them with carb cleaner and let them 
soak for a wile, put the lid on the can and check them every hour or so, keep spraying them 
with carb cleaner to keep them wet, when you remove the carbon you don't want to scrape
it off with anything that will damage the parts, make sure you remove the carbon buildup 
behind the rings and in the ring grooves look close because carbon is there, once you get 
everything clean you need to spend a lot of time looking at each part for wear and cracks.
I will spend over a hour inspecting and evaluating the wear patterns of the top end parts 
use of a magnifying glass and bright light is highly recommended most defects don't jump out
at you they have to be found.

A friend of mine once handed me a cylinder and said "what is wrong with this" after 1/2 hour
he pointed out a crack in the cylinder that I didn't see.

Measuring
You need to follow the service manual real close and make sure you inspect everything 
listed, find anything questionable pitch it and buy new all the moving parts inside the engine
have a cycle life and are considered throw away items.

Bore
If you find your cylinder bore needs to be taken to the next size make sure you find someone
that knows what he is doing (hint 99% of most motorcycle shops don't have a clue) finding one
that does a good job is hard, ask to talk to the guy who is going to do the work, ask him what 
and how he is going to bore and hone your cylinder and how much he is going to bevel your 
ports, make sure he is only going to use a single edge cutter a double edge cutter (cutting edge
180 degrees apart) as one cutter passes over a port the other cutters pressure will change and
you end up with a bore that is not true and uneven, the service manual will give you the port bevel
dimensions and even has a picture you can copy and give to the machinist doing the work.
Ask what kind of hone he is going to use, if they use a flex hone (one with balls attached to a stiff 
wire) request a stone hone, a stone hone will give you a straighter bore and wont affect the sides 
of the ports like a ball hone will when the balls fall into the ports each time around, ball hones were 
designed and intended for use on a 4 stroke cylinder with a continuous surface to run on not a 
cylinder that has large holes in it, when performing the hone you don't want a interrupted cut when 
performing the hone process.

If the guy wont answer your questions and is not willing to listen to you, try another shop, I have found
most poor quality shops will let any and everybody run their boring machine, all they want to do 
is make money and do as many bores as they can to pay for the boring machine, quality shops 
will usually only have 2 or 3 guys that they allow to bore their cylinders, they also know that 90% 
of the people that bring their cylinder to be bored don't have a clue what their looking at much 
less how to check the piston to cylinder clearances once they get it home, most do it yourself home 
rebuilds will just take for granted that the guy doing the work knew what he was doing and wont check
his work.

Once you get your cylinder back from being bored you will need to wash the hell out of it, I will first 
wash it out good with carb cleaner, make sure you wash inside and out, water jackets and ports, 
after you think you have it clean take a white paper towel and wipe the wet cylinder, if you see anything 
on the towel it is not clean, after you get a clean towel wash the cylinder with hot water and laundry 
soap, I use a stiff brush to scrub the cylinder wall, rinse, blow dry with compressed air and oil the cylinder
promptly with 2 cycle oil, let it air dry and it will have rust on it 10 minutes later.
What your trying to do is remove the abrasives from the pores of the metal so the oil film will have a 
place to go once the engine is assembled and running.

Assembly
Well all most ready, first you need to wash the new parts with carb cleaner and coat them with 
2 cycle oil, the oil found on wrist pins and wrist pin bearings is only to protect them from corrosion
you need to remove that film and replace it with oil, if you ever buy a new crankshaft assembly or new
crank shaft bearings make sure to wash them thoroughly I used over a can of carb cleaner on the big end 
of the rod on my new Pilot crankshaft before it would clean up.

The piston will need some attention and preparation too, check out Piston prep before installing your 
piston and rings, the piston will need washed and oiled before it is installed.

more later.....

See anything that needs changed or if you have any ideas send me a email pilot400@mchsi.com

5-15-01
Another hoser production