woohooo! got my 13.5:1 rebuild finished

I finished a winter project on my '00 426 this evening. Well actually several projects, a new graphics kit, and a new Wiseco 13.5:1 piston kit among others. First off, I was a little intimidated since this was my first 4 stroke re-build. It turned out to be much easier than I thought. I did have to do a few things more than once but if I had it to do again right now I think I could do the whole rebuild in 4 or 5 hours. It took me about 2 long days the way I did it this time. If any of you anticipate doing yours I have several do's and don'ts for you.

As for performance, there is a definate increase in bottom end. I just took it out this evening to break it in so I haven't really opened it up yet, but I did ride about an hour and enough to tell you there's a noticable improvement in power, especially bottom and mid. Seems smoother too but that may be because it has around 100 hours on it and this is the first rebuild.

In time we'll see about reliability with the increase in compression but from the short ride this evening I think it was a good move...


[ January 19, 2002: Message edited by: MikeOK ]

I could really use some pointers. If you could give me some do's and don'ts I would be gratefull.

Thanx, yamie rider

Only 100hrs???

I would hate to find out how many hrs on my 99'!!! :)

Yo Yamie- I was going to try to get one more moto season out of my bike but I'm glad I went ahead and did it now, because after seeing the cylinder I'm pretty sure that if I had gone another year I would be looking at re-plating. It was still in good shape but I could see the beginnings of some lines in the nyk plating already. I'm guessing at my total time but i figure it's 100 hours or more.

The main thing I can say is to read the manual very thoroughly before you start, then read it again at each step right before you start that step. One thing you need to do is mark your flywheel with something like a permanent marker with the cams lined up as it shows in the book. The timing mark is there but it's most likely just off to one side or the other from the groove. Another thing I did and used often was to take digital pictures as I went, then look at them on the computer as I re-assembled.

The only real problem I had was when I pulled the cylinder head off I turned it sideways, not knowing that the valve lifters would fall out, and the little pads inside them. I was lucky enough to be able to figure out where they went. You might want to remove each valve lifter one at a time and write down the number on the pad because they are all different. That way you will know where they go if they fall out and it might be a help getting the right pads if your valves ever get out of spec.

One other biggy was that I dropped one of the circlips down into the crankcase (bummer!!!) it took me 2 hours to find it again. I was thinking there for awhile I was gonna have to split the cases to get it out. It's a good idea to keep a rag stuffed in the hole just in case you drop anything.

The cams went back in very easy. I have read on here all kinds of complicated ways to get everything lined back up and in time but as long as you have the mark on the flywheel it's impossible to have your timing off. Also I dropped my cam chain several times down into the case, and I've read that this is a no-no. Maybe I don't understand or I just got lucky but I just pulled it back up with a pair of needle nose. No big deal. It is important to have all the slack out of it when you start putting everything back together but otherwise don't worry about it too much. I used a piece of string tied to my frame to keep track of the chain.

It can all be done with the engine in the bike, but I ended up having to take mine out to get the clip out of the crankcase. After I had it out I found it was easier to work on anyway, and it's not that hard to get out so next time I will take it out first thing.

I can't think of anything else right now but I'm sure there's more. It was fairly easy to do. Not nearly as easy as a 2 stroke but after you re-build yours all the other jobs are that much easier. Ask away if there's any way I can help...

Thanks four the help mike :)

Another thing to handle the chain when dropped that worked for me is that I have one those magnetic pick-up tools(for when you drop bolts, nuts or the such). It works like a charm as I dropped it a couple of times. LOL

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