RZ350 2-Stroke Street Bike

Random Update

2005-06-07T01:30:00.000-04:00

I figured I should write something because it's been a while. I'm pretty sure no one really reads this for my commentary, but you're getting it anyway!

I bought a spare bike. It was supposed to be a replacement for those down times with the RZ, but I fell in love with it.

It's a 1980 CB750F. It weighs 200lbs more than the RZ and has 30 more horsepower... which actually makes it quite even.

If you read down a little, you'll see I had a issue with a blown base gasket. Well... the gasket blew out in the exact same spot again. I said a lot of very bad words when I saw it. So, I have to pull the whole thing apart again, and not only fix the gasket, but find out why it blew out twice. Unfortunately duct tape won't help me here.

Anyway... I realized my email address is no where on the site... so if you have any questions/comments/death threats... send them here cmiller82@netscape.net

Winter Sucks

2005-04-03T17:27:00.000-04:00

Winter is almost over. Last week I put the battery back in the bike and took it for a quick spin. The problem with power above 6000 RPM is still there, the strange thing is, it's only there before the engine warms up. After 5 minutes of riding the bike is fine. I still think it's the YPVS valve controller... I'll hopefully find out this week.

Trouble above 6 grand

2004-08-29T12:01:00.000-04:00

The bike was pulling hard right until 6000RPM. Then it would bog and run like crap. The rev's would still climb, but very slowly. I thought the worst and assumed bad compression... luckily I was wrong.

The connector to the YPVS was rusted up and not making good contact. Also, for some unknown reason the battery was dead. After the connector was cleaned up the bike runs better than before.

BTW: Try riding your YPVS with the valve open and the servo disconnected... it really shows you why the system was put there. There is almost NO power under 5000RPM and then at around 6000 the bike comes alive

R6 Rear Shock Install

2004-08-17T16:08:00.000-04:00

Let's start with the pictures: Photo Album

The shock install was a little harder than I thought but I was well prepared and it took almost 5 hours.

Start by ordering everything you need. You'll need an R6 rear shock. You'll need the shock off a 1999-2002 bike, it has the reservoir mounted horizontally, the new ones mount it vertically and it won't fit.

Next you'll need to order some brass bushings to press in to the shock mounts to make everything go back together properly. I ordered them from McMaster-Carr

Thanks to This post for the following info. Edit: The post does not exist anymore.

For the upper bushings: 2 X part # 6659 K36 Metric SAE 841 Bronze Flanged Bearing for 18mm shaft diameter, 22mm OD, 18mm length

For the lower bushings: 2 X part # 6659 K41 Metric SAE 841 Bronze Flanged Bearing for 20mm shaft diameter, 24mm OD, 16mm length

After getting the R6 shock you need to remove the bushing from the top, and the bearing from the bottom mounts. Do yourself a favour and bring it to a shop and have them press the old ones out, and the brass bushings in. I did get by using a hammer and assorted sizes of sockets though.

Figure out how the compression and rebound damping work while the shock is off the bike...

Just to prepare, read the Haynes manual on how to remove the rear shock. Basically you need to remove the fairings, exhaust pipes, the seat, the side/rear fairings, and remove the oil tank to make things easier. Also, take out the bolts holding the rear brake on. Once the swingarm is free to move, it may pull on the brake line.

After the old shock is out, you'll need the upper bushing, it will fit right into the new shock. The lower bushing was a bit tougher to get it... more on that in a bit.

The new shock has that big reservoir on it and makes it difficult to get in and out. Remove the rear wheel and rear fender to make things easy. The airbox will also have be removed.

Now, the new shock has a compression adjuster that interferes with the frame. I used a dremel and made room for it. You'll need to keep fitting the shock to find out how much to grind away. After the shock fits, then put the top bolt through, and make sure the shock can swing far enough back so the lower linkages fit. There will be some side to side movement of the shock in the upper mount, make sure that when the shock is over to the left that the shock can still swing to reach the lower mounts.

The top bolt is easy... just tighten it up. The lower is a little more difficult. The bushing didn't slide through easily for me. So I covered it in grease, got everything lined up, and started bashing it with the hammer. Then I had to give it a couple of taps from the other side to settle everything. No problem!

Once that's all together, go back and double check all the bolts are tight.

Now start putting all the other parts back on. Two things... the fender and the chain guard will need to be trimmed to make room for the reservoir. No big deal, it's just plastic. Once everything is back together double check the clearance on the reservoir to the chain guard... I had to cut it back quite a bit.

All the pictures in the album are stored in high resolution, save the file locally and zoom in to see things easier.

Ask your questions here in the comments, or use the comments on the pictures in the album.

All Done!

2004-08-06T23:27:00.000-04:00

Everything is all back together... I'll let the pictures tell the story.

Click here for the pictures

Update

2004-08-06T12:18:00.001-04:00

The wire for the alternator was too thick, I already have the right size and I'm going to attempt to rewind the alternator again tonight.

Last night I was bored so I yanked out the fork springs and put in the Progressive Suspension fork springs and changed the fork oil. I put in 15wt oil and removed the spacers for spring preload. The front end feels a lot better now, it isn't bouncy anymore. I'll have to wait to test ride it.

The only thing I'm really waiting for now is the R6 rear shock. After that the bike should be good to go... until I think of something else I want to change.

The bike is apart again...

2004-07-30T13:57:00.000-04:00

The alternator didn't hold up very long. There was another broken coil. The alternator is just too old, even if I fix the break, it won't last long.

It is about $150 to have the alternator rewound, I've decided to do it myself. I've ordered the magnet wire, and I'm going to pick up some epoxy. The wire should be here next week.

I have an R6 shock on the way also and I'm going to rebuild to forks too.

Fun, fun, fun!

New project: Suspension

2004-07-26T23:30:00.000-04:00

Now that all the engine problems are out of the way I'm going to switch my focus back to suspension.

The suspension on the bike is stock. The rear shock is mushy and the forks are so soft they almost bottom out under hard braking.

I already have a set of Progressive Suspension fork springs in the box, and a liter of 15 weight fork oil. I'll be putting them in soon.

To take care of the rear end, I just won an ebay auction for a stock R6 shock. I also ordered the bushings necessary to make it fit. Pictures and specs will be posted soon.

Back Together!

2004-07-25T21:39:00.000-04:00

I took it for spin in the morning, the bike runs really well. I put 130km on it riding up to a friends cottage. We went for a ride to really rip on the bike and everything held up. I had a problem with the fuel line leaking, but that was a quick fix.

Here I am putting in the last bolt.

As for the alternator problem, my "hack" fix has worked great. The headlights hardly dim at idle and the turn signals work at idle also.

I'm taking bets on the next part to go... what's your guess?

VROOOMMM!!!!!!

2004-07-23T22:38:00.000-04:00

The assembly took about 4 hours. I had to clean the carbon out of the exhaust ports and clean and lube the power valves. The carbs are sync'd, rad fluid is filled up...

Note to self: The bike starts a lot easier when the ignition is turned on.

The bike fired up and ran better than ever. The exhaust pipes heated up together (one used to get hot very fast). The pipes smoked equally (again, one used to smoke more). It idled well and got up to temperature without trying to over heat without air over the rad.

It's cooling down right now, and I'm going to re-torque the head and cylinders. I'll take it for a spin in the morning, get it up to temperature and let it cool again. One more quick spin to really beat on it and make sure everything is holding up... let it cool, then it's good to go.

The work never ends...

2004-07-22T22:16:00.000-04:00

The barrels are off and everything looks really good. The base gasket was really broken, I'm surprised it didn't leak more! I cleaned all the carbon off the power valves and replaced the o-rings and seals. I'm almost finished cleaning the carbon off the pistons and then everything can start going back together.

The alternator is ready to go back together too. I put epoxy over the solder joint, it should hold everything in place.

There are new pictures in the photo gallery

Parts are in!

2004-07-21T22:36:00.000-04:00

All the parts are in... I had to drive to the other side of the city for the second base gasket... oh well I didn't even need it tonight.

Besides the base gasket leak, I had an alternator problem. The system was only making 5 volts at idle, and 10 volts at 5-6000 RPM. After some quick testing I found there was a break in one of the coils.

After pulling the flywheel off the broken coil was found by measuring the resistance of the coil while poking at the windings. The break was found under some windings and was not accessable to fix. So instead of spending $600 on a new alternator I just cut the broken coil out... hopefully it works.

The head came off without a problem, besides some carbon build-up it's not too bad. I'm still waiting to see how the cylinders look.

That's it for today... tomorrow the barrels come off and hopefully the whole thing goes back together...

Waiting for Parts

2004-07-21T12:20:00.000-04:00

Well, some of the parts are in... I'm still waiting for the base gaskets and the flywheel puller. If they come in today I should be running by the weekend.

Photo Album

2004-07-20T11:34:00.000-04:00

Here are the picutres thumbnailed with full size pictures linked

Pictures!

2004-07-19T22:23:00.000-04:00

Here are a few pictures of the tear down to replace the base gasket.

I found that the carbs were not syncronized and some of the rubber hoses where in bad shape.
The inside of the carbs where nice and clean.

I had previously adjusted the YPVS (Yamaha Power Valve System) as it was out a bit and loose.

I'm hoping the inside of the cylinders and pistons are in better shape.

After the parts come in, the barrels will be coming off. Fun, Fun, Fun.

Day 1

2004-07-19T21:47:00.000-04:00

I just created this blog. Hopefully I will actually update it.

This will be a record of the maintence done on my RZ350.

I've already replaced the tires, front brake master cylinder, upper fairing and upper fairing bracket.

Now the cylinder base gasket it blown and the bike is currently stripped down waiting for the replacements...

More to come...