Building a 1981 Yamaha YZ465 Factory Replica...

Where can I get a head gasket for an '81 465? I have searched everywhere with no luck.

DC plastics has a complete gasket set with head gasket. Should be more out there. I just got a 1980 YZ465 and want to get it running too. Still in the research mode.

I just got an email back from DC Plastics and they said that I can buy just the head gasket for $34.95. Sounds expensive for 1 gasket but I guess that might be the only choice.

Take a look here.

Thanks Pete,

I enjoyed the link to the hi-point page! Nice collection of boots you have there!


Here is my collection, old to new...












These guys seem to like them too!

Sorry to be so long in updating this project. There has just been lots keeping me busy theses day.

And what of these other projects? Well, the barn was really looking like hell so we did some much needed exterior repair with some fresh paint.

Paint? Yes, paint!

That ain't namsy pamsy, new fangled and unproven vinyl siding on there. That is good old fashioned, original slow growth, wood siding! And it needed plenty of scraping!




Then I also got distracted by this 1970 Moto Guzzi Ambassador. A family friend had one in the 70's that my dad would help him with on occassion. My dad referred to it as the "Moto $hitbox". I found myself muttering the same thing when recently chiselling out a frozon exhaust nut from the cylinder head (after 1st cutting off the header pipe!).



But that's another story.

Now, while I have been slacking on my postings, I have been keeping up work on the 465... and here is the proof!

First, recall the factory OW machine in the top photo. Compare this to the photo of my 465 (below) as taken in late spring.



The green number plates look great but I was to find out that AHRMA rules require yellow number back grounds. So off with the the green and on with the yellows on DC side plates.





At this point it is nearly fully sorted. Jetting makes a very big difference in how these bikes perform. I am happy to say that this one is spot on and runs extremely strong from bottom to top.

I am very, very pleased with how the bike has turned out. I know I have made a big jump in the project presentation but I still have a lot of photos and documentation on what it took to get to the finish line. I will continue to post that material for others who may find it useful.

So whats next? Well, here are the 250 experts leaving the line at Bridgehampton in 1979. Number 64 is me! Haha, will I still have the nerve to line up again???:eek1 Stay tuned!!!

Glad to see you back Kevin, I was wondering what happened to you.

How about the fork height in the triple clamps for the 1981 YZ 465. I forgot to measure it before I pulled it apart, thinking that the owners manual gave that measurement but I don't see it in there.

Mine are set at 47mm (not including any of the cap). This worked decent on both a woods setting and MX track. Fork hieght has to do a lot more with suspension set up & the type of riding your doing. Typically, the 465's didn't turn real great so likely the forks will be placed high. If you look at old photos alot of the pros ran then quite high in the clamps.

Running the rear as high as I could get it and lowering the toobs in the trees helped my '80 w/'82 forks turn decently.

never get tired of good 70's mx shots. got anymore in a larger size? thats really sweet. so is your YZ 465, I think if I had moved from a KDX 400 to a YZ 465 I could have had one more brush with greatness in 82....

I had an 81 YZ465 in the late 80's. It was around 88. Man it was a bear to kick over. It ran like a scalded dog, way faster than I was. But man was it fun. We ran 1/2" zips into the knobs for ice traction. It spit them out like bad chiclets! I wish I still had it.

FJ_Kevin, You mentioned somewhere, that you had been welding the clutch cover of some of your YZ-engines. We have a small crack in the clutch cover of -87 490. It will be fine for this season with a bit of epoxy, but I'm hoping to weld it during the winter. Do you know what sort of Magnesium mixture is used in the sidecover? What sort of filler did you use?
The crack is about 5cm below the starter shaft and I'm worried it might be getting larger.

Hi FJ_Kevin,
Great reading your thread on your YZ465. I had a 1981 YZ 250 H and my brother had the 465, great bikes! I have the chance of getting a 1981 250, and your thread has only made me want it more. These 80's Yamaha's are awesome machines, I remember watching Hakan Carlquist win at Farleigh Castle in the U.K,I think it was 1983, he was a tremendous rider that year.

You can generally weld mag with commonly available rods no problem. However if this proves to be impossible, then get a scrap case and cut this up to make filler material. Repairing with epoxy makes welding much more difficult, as its very hard to get rid of the epoxy completely before welding.

Hi Folks,

Although it has been awhile, I have been preparing some more material to post for this project. Unfortunately, I now I have another reason to post.

Last night, 10/5/12, my 2nd garage was broken into and the bike feature here as well as another '81 yz465 where stolen from me.

I did not get around to writing down the serial numbers from either bike and of course feel like a real idiot for not doing so. Too preoccupied with making an honest living I guess.

There is still a chance I have a photo that could turn up a frame number for the project bike but I am still looking.

The engine serial number is 1LV-002167. This number is for the bike featured here and shown again in photos below. This is the motor composed of yz490 cases and yz465 top end.

I still have my IT490 as that was in my main garage being readied for a cross country race tomorrow.

I also had some street motorcycles in the same garage but they went out of their way to take the dirt bikes, living behind the street bikes. As luck would have it the street bikes were insured against theft but the 465's were not. So the time, money and effort will be a total loss to me unless recovered.

Please keep an eye out for these bikes. They were stolen in Owings Mills, Maryland
My email is kgfaison@msn.com. I am posting the bike featured here. This bike is race ready. I am still looking for photos of the other one.

$500 for info leading to full or partial recovery of these YZ465's

Thanks,
Kevin





Here is the garage door as I found it... you can see how they pushed in the glass to unlock the door.

Damn!

Sorry to hear that. I'll keep my eyes out. Hopefully they'll try to ride them sans gear and the bike will eject them in correct fashion causing grievous injury.

Thanks guys...

I replaced the garage door today and have moved my other bikes to a more secure building.

We have a lot of folks now keeping an eye open for these 465's so who knows, maybe they will turn up eventually.

In the mean time I still have one more 465 parts bike, looks like it will be a busy winter.

I have a few parts for my '80. If ya need a particular item lemme know.