Andrea Bartolini YZM400F engine and project.

Factory teams are exceptionally touchy about works bikes getting out of their hands for a host of reasons, some related to protecting proprietary info, and some legal.

Sidebar: Back at the end of the '60's, early '70's, GP road racing in Europe was a wide open, works bike, Formula 1 kind of affair dominated by factory "fire engines" like the MV Augusta, and outrageous things like the Moto Guzzi V8 (I know what I said...not a typo ;) ). Honda had some of the best of these in the late sixties, among them the 297cc 6 cylinder they dominated the 500 class with. It was a 250 originally, but it was faster than anything in the big class, so they bored it enough to meet the class rules.

Races in those days were subject to claiming rules, although no one had claimed a factory bike for a very long time. One day, a Euro businessman claimed Mike Hailwood's 297cc six for some obscenely low price. Honda made no fuss about it whatsoever, and politely presented the new owner with his prize. Then they pointed out that the engine would need a rebuild, having just been run for its second GP race, and saying that they had no idea where the new owner would be able to find parts for it.... :smirk:

But I digress. Back to the thread. :cheers:

Factory teams are exceptionally touchy about works bikes getting out of their hands for a host of reasons, some related to protecting proprietary info, and some legal.

Sidebar: Back at the end of the '60's, early '70's, GP road racing in Europe was a wide open, works bike, Formula 1 kind of affair dominated by factory "fire engines" like the MV Augusta, and outrageous things like the Moto Guzzi V8 (I know what I said...not a typo ;) ). Honda had some of the best of these in the late sixties, among them the 297cc 6 cylinder they dominated the 500 class with. It was a 250 originally, but it was faster than anything in the big class, so they bored it enough to meet the class rules.

Races in those days were subject to claiming rules, although no one had claimed a factory bike for a very long time. One day, a Euro businessman claimed Mike Hailwood's 297cc six for some obscenely low price. Honda made no fuss about it whatsoever, and politely presented the new owner with his prize. Then they pointed out that the engine would need a rebuild, having just been run for its second GP race, and saying that they had no idea where the new owner would be able to find parts for it.... :smirk:

But I digress. Back to the thread. :cheers:

True I have to be real careful with this engine. So far there is nothing that is not custom made. I did get gaskets with it.

Some new things in the investigation of this engine. First concerns were ignition and carburetor.

The stator and flywheel are totally different than production. It has been very puzzling with the YZM having only four wires coming out of the stator and when I took photos of Doug's bike there was a strange module where the CDI should be.

Turns out this is a crude, old two coil magneto style. I tracked the module unit on Doug's bike down to being a regulator rectifier. These bikes did not have a CDI.

Then you say, we'll what about throttle position sensor? Doesn't appear it used one.

In investigating the carb, I notice Doug's throttle linkage is on the left side of the bike but I can't see the carb from right side. Since there is no CDI it's not likely one exists. I question Pete Steinbrecher about CDI. He said he didn't understand and asked me to clarify what I was talking about when I said throttle position sensor.

I have not heard back from him yet, so I can only guess the bike never had one, so he would not know about it.

I would like to find out what carb model they used with throttle cable hook up on left side. It 's same CR style as production bike.

Looks like the CDI is getting pulled on the donor bike. I found a company with reg/rectifier module.

Wow, how'd you get your hands on that engine? You are one lucky guy.

Wow, how'd you get your hands on that engine? You are one lucky guy.

A guy who bought it decided he wanted one of my restorations. So we did some bartering. I have a small fortune in the engine now.

Update,

I got all the European white plastic. Having red and black decals made now. Once I get decals on, I'll size up the seat for a custom two tone red and black.

Still struggling with ignition. May have to rewind the stator so we can get it to have battery charging.

It appears we have come down to having to build our own ignition system for this engine.

Plan is to rewind the stator so it can produce enough power to charge a battery , add regulator/ rectifier and a programmable DC-CDI.

If you have recommendations for a unit, I would like to hear about them.

Rob

I got the engine into the donor bike and it has room to spare, accept the frame will need to be modified to get carb on. Two questions. Doug Henry YZM400 has a keihin CR carb but the throttle is on the left side of carb. Does anyone know which model is like that? Never got the model number off his bike.

2nd question, is Fluidyne the only company that made over size radiators for YZ400F?

I need to buy over sized radiator since this engine is wet sump and only .7 quarts of oil. I am sure cooling is a must.

Rob

After going speaking with few people I have a plan for ignition. According to Bob Oliver, he said the YZM ignition system was DC-CDI unit. He could not tell me anymore. That explains the regulator/rectifier on Doug Henrys bike. The flywheel and stator was made by Denso. I contacted them and all they could tell me was the part number, confirmed it as prototype.

It took the flywheel and stator off and sent it out to Rickystator. Mike confirmed that we can use the stator and will be good enough to use to charge a battery.

The CDI unit came down to Zeeltronic. It has 2 maps and selectable on the fly.

Each map has three throttle position maps with 12 points each.

Does anyone have any suggestions as to advanced numbers for the 400 engine?

TPS is 33, 66, and 100%

Then I have 12 points to fill in for each.

Rob

It's been awhile, but I am finally back on the project full time. I updated my website to show some of the work completed. I was shooting for completion at end of month in time for Vintage Days in Ohio.

Not sure I will make it.

http://huskyrestoration.com/?page_id=2602

Some nice additions to the project.

Thanks to DRD Doug Dubach for the beautiful custom made carbon fiber muffler, designed with same carbon fiber as used on Doug Henrys YZM400 and Andrea Bartolini's YZM400.

I also just added a carbon fiber air box to the titanium sub-frame and finished machineing the carbon fiber engine mounts.

The bike is coming along nicely. Clink the link in other post for update.

DRDmuffler.jpg

Edited by artracing

1997 YZM400F Engine Starter circuit designed and tested July 27 2013

DSC06452.JPG

Click this.

Edited by artracing

Oh this is going to be cool when its done.

I got side tracked having to make a living. This bike will all come together in next few weeks. So stay tuned.

Here is what we had to do for the twin port exhaust.

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Very cool project !

More progress. Started build

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Pretty slick so far :thumbsup:

Interesting project and looking forward to seeing it come together.

 

Are the two crankcase halves actually machined from billet? From the pics it looks to me like all external surfaces on them have machining marks.

Interesting project and looking forward to seeing it come together.

 

Are the two crankcase halves actually machined from billet? From the pics it looks to me like all external surfaces on them have machining marks.

Oh ya ! The whole engine is billet except for case cylinder head. Even the little sprocket chain guard is billet. The two side covers are billet titanium. All the bolts are titanium.

Want see some billet? Drool over this.

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Like looking in a jewelers case.

WOW, I've officially drooled here...thanks for those pics. :thumbsup:

 

It's amazing to see Yamaha put that level of effort and expense in to an effectively low number of prototype engines.

Begs the question who still has the drawings or CAD files to knock out a few more on a milling machine!!

 

As grayracer mentions, in the past there were some weird builds by the manufacturers. Honda made a 5 cylinder 125 four stroke. The pistons must have looked like thimbles! And it's hard to comprehend how the weight of all those reciprocating parts and the valve gear would be an advantage when one considers the frictional losses. And there was the oval piston NR500, basically a V8 but with only 4 cylinders to get round rules.

 

This YZM single cylinder engine is far more conventional in design but just as intriguing when you consider how they optimised it for it's intended purpose.

 

It's great to see this sort of project and I'm certainly looking forward to seeing it come together even more so now. Cheers.

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