How's this piston? (56k BEWARE***)

[kilabeez0]

http://www.imagestation.com/picture/sraid67/p21a4baf9135b8686954a7dd83bce6035/fbd47e8b.jpg

http://www.imagestation.com/picture/sraid67/p5e34c953034fb4193b5906c96eea8433/fbd47f28.jpg

http://www.imagestation.com/picture/sraid67/p509d75b627d8f6edfaa6ce6ee2c7df14/fbd48424.jpg

[kilabeez0]

Cylinder and Head





http://www.imagestation.com/picture/sraid67/p9f2007b8399a9a526bd082f43c94fd46/fbd48443.jpg

http://www.imagestation.com/picture/sraid67/p818f331548882d46ea789f4765f5bb66/fbd484d5.jpg

http://www.imagestation.com/picture/sraid67/pdbd0bf5d10408066ba62cac71f6b6dd5/fbd48466.jpg

[kilabeez0]

Exhaust and Rusted Front Sprocket shaft

http://www.imagestation.com/picture/sraid67/p364bf7beb432241da9887d4b3217514d/fbd48491.jpg

http://www.imagestation.com/picture/sraid67/p6b60f1829b62db846f92c42d43b41b76/fbd47f02.jpg

http://www.imagestation.com/picture/sraid67/p86d3382d545c7a8e5c18f901585c14ef/fbd47eb8.jpg

[kilabeez0]

This is the first motor I've ever worked on. I've done everything other than a motor.

I'm checking with a micrometer to find out what bore it's at. When I do I will take it to a machine shop to clean up and do whatever is necessary for a rebuild. I was quoted $40 for hone and cleaning, and $20 for a valve job.

I'm making a list of things I will need for a full rebuild. I'll post the list after some of you make some comments. I obviously need a new piston, rings, gaskets, etc. But do I need new valve seals? And what other things do I need to order from Honda for a rebuild? And what exactly am I supposed to have done at the machine shop. Thanks.

BTW this bottom end is junk because of that stripped shaft. I bought one off of Coty in place of it...it better work when it gets here!! :twisted:

[FullBore]

That all looks ok, it might need a bit of thought on the sprocket shaft, as to if it should have a new one or not but the piston and bore looks good, it looks as though the piston has been a bit hot at some point but it won't hurt it and you can expect that with air cooling anyway.

Nat

[Truckster]

I was quoted $40 for hone and cleaning, and $20 for a valve job.


:shock: :shock: :shock:
I Wont tell you what I was quoted here in Aussie, but you can nearly times that by 5....

piston looks like its suffering from detonation, My TZ used to suffer from that BADLY!

Other thing that can cause it is water.

[bakeban]

the piston looks bad but you might be able to salvage it. first thing i wouild do is buy the clymer book. it will tell you where the o rings go. when you put the cylinder and head back on, there are o rings that go on the studs. might as well get the valve seals done since the motor is already apart. at least get it honed and if the cylinder is out of spec, get it bored. then you will have to buy a bigger piston. you might be able to find a good deal for a whole motor on ebay. hope this helps

later

[kilabeez0]

I checked the bore with calipers and it's the stock bore. Do I need to take it to the machine shop before I order a piston and have them check the head professionally, or should I just order a standard bore piston?

Do I need to order anything from Honda to give to the machine shop?

[J.D.]

If the cyl is stock bore, you should just be able to order stock rings and piston and not worry about bringing it to a machine shop except to have it honed. If I was you, I would just buy a honing tool, they only cost 25 bucks for me, and if you bring it to a machine shop, you got your time, gas, and your out 10 bucks. 10 bucks is what my machine shop charges anyways.

[kilabeez0]

well i have a friend who can hone it, but i'll still bring the head to have cleaned and the valve seats re-surfaced.

[Dirtcrasher]

Stock bore, thats great! That tan discoloration dosen't look like detonation to me but rather oil getting past the oil ring - merely because it was tired. Did you use an inside teloscopic gauge and then a micrometer? You really have to measure it that way and in the 2 ends of the cylinder and the middle. One of the best mechanics I ever met had some long thin feeler gauge stock - he'd just drop one in there and put in the piston and add more until he got a clearance. This of course was a real quick way of checking for overall wear on the bore.
They need the new piston to bore it correctly if you go with an oversize, but if that stock puppy measures up ok and isn't all scratched up I would just re ring it.
I don't know what to say about the valves - Honda valves are coated and should never be ground or lapped therefore how do you improve the seat?? I guess they just grind it and that works?? I always thought lapping was the "honing" of the seat to really get it tight but if you can't lap it I guess just replacing the seat is the only way to go. I bet MR ATC could help, throw him a post on the head question, I'd love his input. Good luck!

[kilabeez0]

^^^Now i'm all confused :?

So if my engine is covered in carbon and looks like crap, what exactly am I having the machine shop do to it?

[bakeban]

have the machine shop check the bore and if it is to spec have them hone it. use a wire brush on the piston to clean it up but dont go nuts. have them also check the valves and have them put new valve seals on. that is what i would have them do

later

[Truckster]

Clean the top of the piston, NOT THE SIDES with wire brush, get all the crap off it, take another photo and post it.

closer look at the pics, yea its more carbon than detonation but yea clean it up..

A hone, just tidys up the bore...

[kilabeez0]

will an anutomotive machine shop have the valve seals, or is that something i need to buy from honda and give to them? thanks for all the help btw.

[Truckster]

will an anutomotive machine shop have the valve seals, or is that something i need to buy from honda and give to them? thanks for all the help btw.

No unless they sell trike bits you will have to give them the bits.

If your having the head done, give them piston, seals, valves etc to get correct measurements done.

if your only haveing the barrel honed, just hadn them the barrel and piston

[kilabeez0]

http://houseofmotorcycles.bikebandit.com/PartsBandit/Assets/schematics/Honda/H00790007.gif

Sorry for being an idiot, but other than the seals what else do i need?

[bakeban]

nothing unless your cam is worn any. if it shows signs of wear might as well replace it while you have the motor apart. look for heat marks on the journals and the lobes too. also check the surfaces of the rockers where they meet the cam lobes. they should be smooth.

[Dirtcrasher]

Now don't get all confused, I tried to be as specific in my post as I could. As far as the cam - there again there is a spec in the book for cam lobe and journal diameters. Just mic them up. Problem with four strokes is alot of people don't maintain them and a lack of oil in that head will cook the cam, rockers, journals etc. Just measue them up and look for scratches or scoring in the aluminum where the cam rides. If there's play in a shaft then it's on it's way out. But I thought you got a good head?? Thats why there are so many ATC parts, noone can keep the motors going usually due to lack of maintenance. Too bad everyone didn't know that the smallest amount of damage to an aluminum journal will destroy a whole top end. These motors really do require time and patience and 1 mistake will make that repair last less time. Have you read the manual about inspecting parts??

My mechanic told me years ago just to pour gas in there and see if the valve leaks it past and if it didn't he left the heads alone.