The Matrix: Rebuilding By runningslow (Read 25,942 times)

[runningslow]

So, I've decided to use this thread as my record of the process as I rebuild the Matrix. I'll try to keep the current status in this first post with pictures as the thread progresses.

Current Status: IT'S ALIVE!





****BEGIN ORIGINAL POST****
I picked up an inexpensive short case motor, figuring I could use it as a parts motor for my longcase. But.. I don't know what, if anything, is good on this motor. By the looks of it, it may be a bit gummed up, but salvagable.

What I'd like to know, is it possible to bench test a motor? Or, would I have to go to the trouble of mounting to my frame and connecting everything? Or are there ways to determine the condition without even running it?
****END ORIGINAL POST****

[Alleyoop]

Pretty hard to bench test a motor without the proper connections available. You need something to hold it down, feeding it gas, Juice to your sparkplug at the right timeing.

So for us wrenchers its take the old motor out and put the other motor in. You can check if the pistion moves up and down by turning the crank. You can take the head off and check the valves, springs etcc, timeing chain, pistion see if it doesn't have a hole in it etcc.
Alleyoop

[runningslow]

Pretty much what I thought. The engineer in me was envisioning some elaborate test apparatus with a place to mount the motor, the necessary buttons and switches, and a gas supply... I guess that equals throwing it on a scooter. Ha.

I'll check out the motor more later, but after my initial check last night does not seem promising. I could turn the crank, but it was definitely not easily. Not like on my Matrix. Anyway, I have bigger fish to fry first.

Also last night, I pulled off all the rear plastics to expose the motor on my scoot. She looks so undignified sitting there all naked, but I left her top on, so she's not fully exposed. Ha. Ok, now I'm getting ready to dive into trying to fix it. Frankly the idea of tearing into the motor is a little nerve-racking to me. I don't want to screw this up. So.... I've got a couple questions and I'm sure I'll have more later on.

How do the wrenchers around here work on your bikes? Do you have a stand to raise the bike or do you just work on the ground?

Is it better to remove a motor from a bike to work on the motor, or should it be possible to disassemble it while still mounted?

How hard is it to pull the motor? Does someone have a step by step?

Should it come to it, is there a good step by step on how to split the case?

Does anyone have any general tips?

Naked Matrix:

[Jon C]

I'll be following this post, hope it goes well. I came across this last night:



Jon

[runningslow]

The scoot has run great in the past with regular maintence and the odd repair at a B&M store. But, now that they are no longer an authorized UM dealer, they won't do much.

After the motor seizure incident described in my "Sign in sheet" thread, I had been able to get it started once or twice, but now it will not start at all. It'll crank, but has a horrible rattle.

I'm hoping the problem is just in the top end, I don't want to dig deeper than I have to. I'll probably post an update with some more pictures tomorrow.

[runningslow]

Oh, and the kick start is broken and I never knew if it worked or not. I know the pics are not the greatest, but you can see that the kickstart shaft is gone in the one that shows the CVT cover off.

My phone usually takes decent pictures, but it was getting a little dark in the garage. I was surprised that they turned out as bright as they are.

[Bashan]

Great post Jon, appears I was wrong. I'm going to put that video in the tech section. Hey Josh, how much are you willing to spend on this engine? It might be easier to get a whole new engine and put it in. Or are you intent on taking it apart to learn from it? From what I read on your other posts, it sounds like it's toast. Rich

[runningslow]

Well, I'm planning to use it as a learning experience one way or another. I may just do a whole new motor if it comes to that, or if the parts lists looks to be too expensive after th diagnosis.

[runningslow]

First new pic of the day. I drained the oil and held an old hard drive magnet in the stream. Look at what I found....



The magnet on the right is clean (for reference).

I'm off to Wal-Mart to grab some supplies I missed in my earlier trip... I need to start making lists...

[runningslow]

So, here we go. I've disassembled the motor, only to not find anything earth shatteringly wrong to my amateur eyes. Sure, there seems to be a bit of residue and other crap in the cylinder, but can someone see something I can't?

Everything in the top end appears to be intact and the crank turns effortlessly. I have no idea where the metal shavings in the oil came from. Seriously... .

My Engine Tour Guide:

[runningslow]

There were alot more metal shavings in the bottom of the drain plug, that I hadn't noticed when I took the first picture this morning. I didn't take a picture of it, and I have now cleaned it up.

Anyway, the connecting rod does have a little wobble to the side. Not much, maybe a millimeter or two. Should it have *zero* play to the side?

I guess its time to drop the motor.

[runningslow]

I'm calling it a night. I've got the motor pulled, with the wheel still attached, because I cannot figure out how to pull the wheel. I removed the axle nut, but the wheel and the bracket on that side would not come off.

Since I had the motor off, I mounted up my parts motor to check it out. No love. When I hit the starter switch, all I got was a squeal from the starter. I couldn't budge the kickstarter. Ah well. I'll troubleshoot that another day.

[Bashan]

Is that a disc brake on the rear? I couldn't tell from the pic, maybe that complicates things. Mine's a drum, remove the suspension bracket and axle nut, and it slides off the axle splines.

[runningslow]

It has a rear disc brake. I got the caliper off just fine, but there's this bracket that will not slip off. I remove the axle nut and the shock and nothing.

No, I don't have the Haynes Manual, yet. Well, I do have 3 or 4 Haynes Manuals, just not the Chinese Scooter one. I'm planning to get it soon.

I'll probably try digging deeper into my motor this afternoon.

[runningslow]

Is there a good guide somewhere on how to open up the crankcase? I'll keep looking, but I hoped someone could point me in the right direction.