did a top end inspection.. *updated with pics!*

[brentn]

So I took off my jug today and wanted to check everything over and make sure that my engine was not going to explode this summer.

I checked out my piston and it does not have any cracking, dents etc. However there are a couple small scuff marks on the side of the piston running from the lower ring vertically straight to the end of the skirt. I will post pictures later tonight, but is this from a little bit of cold siezure?

The cylinder still had visible cross hatching and there were no marks that I could initially see. The power valve was full of oil but when I cleaned up all the components it looked really good, no signs of a blow up from the previous owner. Rod had the usual small side to side clearance, but no up and down play at all. The piston pin did not have any play in the piston, but I have yet to check the piston pin bearing for play... Should there be any with the bearing installed onto the rod? I think side to side is normal for the piston/rod/bearing but not to sure about up and down..

The cylinder is soaking in a sealed tub of gasoline, I didn't have any other cleaner in large quantities.. Every couple of hours I'm swishing it around just to get rid of the spooge inside the power valve compartment etc.

Cylinder head was very clean, no carbon deposits at all, there were some small carbon marks, very light, around the inner head gasket. Could have been a small leak into the coolant system but I have never seen the radiator puke fluid, and I've been riding it fairly hard the last 12 hours. It's probably nothing..

Piston was fairly clean with just a little bit of carbon on the dome, I cleaned it up a little with steel wool and now it's really smooth.

Anyways I'll post some pics up later tonight so you guys can analyze the condition and tell me what you think.

Thanks for your time.

[brentn]

Ok so here are the pics;

I cleaned up the piston as best I could, used steel wool, dish soap, and hot water, worked really well actually.

No cracks on the skirt inside or out

Here are some more minor marks

No cracks on the inside

I checked the ring gap and it was just within spec throughout the cylinder, I mean right on the edge of the specified limit

The clearance between the ring and the crevice where the ring resides was 0.06mm except for a couple spots... again just within the spec, the limit was .1mm

The cylinder was pretty good except for three little marks here;

here

and finally here

I could not feel them with my finger nail, so they don't go beyond the nikasil coating, I don't have a micrometer but if I can't feel it with my finger nail it should be ok yea?

Finally there was what looked like porting attempts or cleaning, I don't know. Looks like they picked up the dremel, touched it and then put it down lol.

These surface marks were on most of the ports, I'm thinking that they were trying to clean the carbon off using the wrong tools, who knows.

I'm going to do a top end before summer, but this should hold up fine until then, bike runs great, compression was 180+ and there are no cracks and there was NO carbon buildup.

If anyone see's anything that I should be aware of in these pics, let me know!

Thanks!

[honda_best_789]

looking at the first picture of your piston i think you are running lean somewhat... i had my piston in this week at my college and one of my teachers had said if there is sorta sand paper looking marks on the edge exhaust side on the top of piston thats what its from

other than that i think it looks pretty good

[Zaz]

That looks pretty normal. Why not drop in a new piston while you are in there? It dosen't have any blow by marks but does show some scuffing. Just to be safe.

[brentn]

$ is the problem

[kantoniak]

$ is the problem

Looks all pretty normal to me. You could just do rings for a fairly cheap price but even the piston and ring kit should be less than $200 CDN. ($162.95 for Wiseco in BC so save yourself another 7% being in Alberta).

Either way, depending on how you ride and what type of load you are putting on the engine you should be fine for a while. You would notice a nice 're-freshing' pull though with a new piston!!

[ajd187]

My piston looked just like that, including the mark on the exhuast side. I replaced it but only becuse I had it open and the piston out.

[jwherb]

Hardcore.

If I'm tearing out the piston and cleaning everything up to the degree you are I'm throwing a new piston in it.

[ForsheeMS]

Your piston should be replaced. It does show some signs of wear and even though it has no cracks it could turn loose at any time. The money you spend now could save you big time down the road by taking a chance. Replace the wrist pin bearing as well.

The cylinder looks ok, not perfect but it should be fine. Scrub it with Scotchbrite and WD40, give it a thorough cleaning and put it back on.

[7thirtyseven]

Gnarlyparts in bc has the wisco for $162... They are great to deal with.

[brentn]

7thirty, thanks, the dealers here in calgary choose the price from random it seems every time you call. One time something OEM is 200$, then 250$ sometimes 160 lol, it's retarded. If gnarlyparts has a website, I'll be checking it out and ordering from them. I used to get firearms and parts shipped from BC all the time, it only took 2 days max and never cost me more than 10$ shipping for large items.

I'm going to leave it, I'm only going to get probably 20 hours or so max in before summer and I'm sure that this will hold up until then. I'll take that chance, as the chance of it failing are still very low.

[7thirtyseven]

No sweat, let me know this summer when you go riding, maybe we could meet up in huntervalley.

[brentn]

Never been there, we do most of our riding in Caroline on the quad trails. Me and my brother are pretty open to new stuff, I however hate the real technical stuff at high speeds, I like to take things slow

[7thirtyseven]

Do you like lifting your bike? That's slow.

[brentn]

No man, I like pushing my bike. I don't even ride it

[7thirtyseven]

I have a great ride planned....

[brentn]

Put it all back together and it fired up on the third kick. First top end job I've ever done and it worked out great, I'll have to see what happens when I take it out for a ride.

I came to realize something though...

If the rings are not aligned with the stop pins on the piston, the piston will not slide easily into the cylinder yea? I figured if you forced it in the ring would be resting on the pin, and things would be very rough when the piston slides up and down..

So it's pretty damn hard to install the rings on the pins right?

[honda_best_789]

i dont think its possible as the piston slides easily into cylinder when installed correctly you would notice an incorrectly installed ring pretty quick as the cylinder would not fit over it

however IF there ever was an instance where someone has somehow installed them wrong, chances are one would have caught a port by now (given you have had your bike running) as rings tend to spin during operation (not on our 2 strokes as thats what the little pins are for)

basically i think its pretty hard to screw it up

[Slick_Nick]

Good stuff buddy. Just saw this thread. I'm still a week or so from getting my steed back up and running ?

[shrubitup]

Good stuff buddy. Just saw this thread. I'm still a week or so from getting my steed back up and running

What brought it down? ?