Lubrication holes?!?

[Glitch]

Hey,
I just did a new top end about a month ago and have about 5 hours of riding time on it. During the installation I saw that it said to drill 3 lubrication holes by the exhaust bridge, but didnt think anything of it(bad?) :eek: . So I was looking at my old piston and saw that it had the 3 lubrication holes, didn't notice them before. So my questions are:
1. Is it bad that I ran the bike for 5 hrs with out these lubrication holes?
2. If it was bad, do I have to get a new hone, piston, rings?
3. If it wasn't bad for it, should I still take apart the topend and drill these 3 holes on the piston in there, or can I just let it slide?

The bike is jetted alittle on the rich side.
Thanks alot for any replys.
Jim

 

[Moto Squid]

Those holes allow pre-mix to lubricate the exhaust bridge of which experiences very high temperatures and expands more than anything else in the exhaust passage. I'd at least take the pipe off and look for scorring on the piston. If it's not bad don't worry but if there's signifigant marks then you need to do something. I really don't know what would be the right thing to do :think:

 

[Glitch]

I looked at the piston through the exhaust port and got a pretty good look at it. The problem is that I cant see if there is any scoring on the piston becuase of the bridge. I cant see a width of about 3mm. So any scoring would have to be in that little area. Would I have to replace the rings if I took the cylinder off for a little peek at the piston?
Thanks Moto Squid for your reply, I didnt know what the purpose of these holes was before.
Jim

 

[Moto Squid]

No need to replace the rings just because of taking the cylinder off, just be extra, extra careful of not ripping the gaskets. But if you really wanna take stuff apart take the head off because any scorring should be transfered to the cylinder wall vertically from the bridge. But the easist would be to take a look with a little mirror through the exhaust port.

If it were mine I'd check first using the mirror and leave it...just run a good synthetic oil and don't run 'er on the lean side.

 

[Glitch]

Well, I took off the head and the cylinder looked alittle rubbed too much right above the bridge so I took off the cylinder and took out the piston. The piston didnt have any noticable marks, just some rubbing. So I drilled the holes the correct size and put the piston back on. Then I put the cylinder back on and tightned the bolts. Looked in through the exhaust port to see if I could see the holes, which would be bad, I think. I saw the outer edges of the holes, about enough to just barely fit the graphite from those mechanical pensils. :-(. I was wondering now if this is a serious problem, do I need to replace the piston?!? I really dont want to replace the stupid piston which cost me $90!!!!!! Then maybe a hone which is $60. I barely had enough money to get handgrips today. So, is this is a really really bad thing that I can see alittle of the holes, or can I just leave it?
Thanks for the replys.
Jim

 

[marcusgunby]

Do any of the holes line up at all with the bridge?

 

[125 rider]

Originally posted by Glitch
I really dont want to replace the stupid piston which cost me $90!!!!!! Then maybe a hone which is $60.

I think your getting burnt on these deals :flame:

 

[Glitch]

Well, I only drilled two holes, which Wiseco called for. The bridge is only about 2mm wide for most of it. The holes dont line up EXACTLY with the bridge, they are offset to the left about .6mm, so I can see their edges. The bridge will get lubrication from these holes I'm pretty sure, but I was just wondering if it was bad bad that I could see the edges of the holes. I was thinking that it might mess up crankcase pressure or something, I'm not sure. I started it up last night for about 10 seconds and it sounded normal. I can't ride it until next weekend though because I ordered some spacer for the rear hub, and I already took the bearings out.
125 rider - When I asked them how much the piston would be they said probably $70. Put when I went to pick it up it was $90. I didnt ask them why because I figured that since it was a P4 piston that it cost more, and its a 1987 bike. I didnt have a big flame with them because I dont mind supporting them, they sponser Kevin Crine and Damien Plotts. Plus they're kind of a small shop and is family owned, but very good experts.

 

[Moto Squid]

I wouldn't worry...the holes are there and it'll get the extra lubrication. The amount of pressure or pre-mix that might pass through the edges of the holes is so insignificant. Fixing time is over, time to go have fun :thumb:

 

[marcusgunby]

I adgree with motosquid-ride and dont worry.

 

[Glitch]

Thanks you very much Moto Squid and marcusgunby. If we still had mojo i'd give you guys bucket loads, but we dont.
Thanks again.
Jim