Project: Garage Find

The "scorched coils" are nothing to worry about.
Those are the charging coils for the CDI. They run at a much higher voltage, so need to be pretty well insulated. Output can be in the 400v range or more, depending on what the CDI requires.

This is why they look different.

Originally Posted by sath182

Did you ever find out about those three scorched looking coils on the stator? I'd hate to see you have to pull the engine back apart for a failure.

[andrewsmith]

Originally Posted by yorkie_chris

Outside of a tools calibrated range any faith is misplaced!

+1

Rather run the risk with the pikey torque wrench (Right hand with a 1/4 drive ratchet), or spend the cash and get the tools.
A teng torque wrench is £50 new low torques and are calibrated and can be re-calibrated for a few quid

[squirrel_hunter]

Originally Posted by atassiedevil

The "scorched coils" are nothing to worry about.
Those are the charging coils for the CDI. They run at a much higher voltage, so need to be pretty well insulated. Output can be in the 400v range or more, depending on what the CDI requires.

This is why they look different.

Interesting explanation, thanks.

[squirrel_hunter]

To continue the story, I built the second cylinders powervalve today. Not a lot to show for that and fairly straight forward. The powervalves are different between the cylinders but it all goes together in a fairly logical order with new seals.

New studs and dowels that were needed were now on the engine and with the cylinders built it was time to get the pistons on.



I cleaned up the pistons crown with WD40 and a little wet and dry, nothing harsh just to remove the carbon deposits. I've reused the piston pins but am using new small end bearings and circlips. The piston rings were checked at Piston Broke and were passed for use.

Getting the new piston circlips in was easier then the last time I tried it which was nice, but I still had the bottom end sealed up with tissue just in case. The small end, pin and bore were all lubricated with 2Stroke oil to help assembly.

Being sure that the piston rings were lined up I slipped the barrels over the pistons and seated them on the crank case. It was then time to break out the Yambits order and the new nuts to secure them.



And no sooner did I have the barrels on I was taking them off again. Who in Yamaha thought that design was a good idea needs to write me a letter of apology. The problem is the two lower middle nuts. They are to close to each other and the cylinders overhang the nuts. So to get them tightened up I needed to remove the left barrel and its stud. Then using a crows feet spanner that I can attach to my torque wrench I tightened the nuts up.

Now with one cylinder on it was time to reinstall the left barrel. The opposite nut to the last problem one was just as much an issue on this one. I don't think the powdercoat helped as the extra thickness might have got in the way slightly. But still the design is a pain. Oh and one more thing I found that getting the lower outer nut on to the stud needed to be done before the barrel was fully seated as the cylinder overhang prevents the nut from going on.



But finally both barrels were fully attached and torqued down. While I was doing this I regularly rotated the engine to check that nothing was misaligned. All felt fine as the pistons moved up and down as they should.

I also put the powervalve joiner on which ensures that both valves move at the same time, and checked the powervalve movement was free after assembly. There are a few little external bolts that I will need to tighten properly as I'm thinking of replacing them and I have also to put the powervalve housing and cover on.

I then built the top of the barrels with new studs and an OEM head gasket. The cylinder head was then installed with a Yambits nut kit and torqued up. With the head on I could rotate the crank and with my hand over the spark plug hole I could feel the suction and compression in the cylinders from the pistons, which was pleasing.



Still got lots to do. I replaced the kickstart oil seal and have been doing some painting. Without tempting fate I have a feeling that the engine will be reunited with the frame in the next few days...

[maviczap]

Originally Posted by squirrel_hunter

Without tempting fate I have a feeling that the engine will be reunited with the frame in the next few days...

That'll be awesome!

[andrewsmith]

I want to see this running for christmas

I have to say I'm amazed. I know so little about such things - wouldn't know where to start!
I'm very impressed. The only thing I would say is the finished article is as ugly as sin!

[squirrel_hunter]

Well that was painful. My arms currently look like a cross between self harm and drug addiction, and my back is killing me. It would have been much easier if I had some help with this bit or if I had some sort of hydraulic table lift, but no one was around and I didn't think of the lift (the type to raise Harley's or MX Bikes) so I had to do it the old fashioned way. If you don't know what I did today this before shot might help...



It was a tight fit at the rear with the powdercoat as I had to shave a little off plus I haven't been able to fit the damper washer yet, but the engine is in. Unfortunately not without a slight mishap as it slid off of the jack when my back gave out and I lost grip of it. It slid down and rolled over, but stayed on the bench. I don't think there was any damage as it was gentle. The crank still rotates nicely so only time will tell but I can see nothing untoward on the cases.

But the engine is in an the cradle is on loosely. But I now need to take it out to fit the damper washers, however the plan for this is to remove one of the mounts lift the engine and insert the damper. Simple in its ingenuity, what can possibly go wrong?



But if this doesn't work then I will be taking it fully out and trying again, but with some assistance. And as a note it was a lot, lot easier to remove the engine as it is light. However if you are holding it with one hand, manoeuvring it with the other and sliding the bolt in with your other hand it does start to get heavy quite quickly.

There is a reason that I have fitted the engine at this point even as I still have some issues with the clutch cover as the oil pump retaining bolts are playing up. Investigation is required there. But coming back to the point of the fitting I need to check the exhausts. I have a set of exhausts to go on, but they might need something doing to them. These are not the exhausts that I took of due mainly to them having a similar mass of the moon...

[squirrel_hunter]

More bad news...

The exhausts I have don't fit.

Just lined them up on the bike and while I'm fairly confident that they are 2MA based on the history I have been given I think they will fit a race bike better. The side stand fowls the left chamber and the right foot peg mount is a little out I think they may have been used with rearsets before. Its a shame as I quite liked them.

So I'm now in the market for a set of pipes. I have pretty much decided what I'm going to do but have a couple more options to explore, any suggestions welcome.

[andrewsmith]

Squirrel are they similar to these?

http://www.ebay.co.uk/itm/YAMAHA-TZR...item4d161172ff