1972 450 engine questions

Hi and Merry Christmas to all. This is my first thread, please bear with me.. I have 2 1972 450 engines. The first I think is a WR with a 6 speed trans, engine number is 2120 0008 on the center case seam. I bought it out of Lancaster PA. It was in a 360rt frame and had a cut head for I think a 400 pipe. Everything on the bike is pretty crappy! When I pulled it apart, the usual, flywheel stub thread gone, stub drilled off center and standard 3/8 16. Bearings smoked, rod, big and little bearing surfaces NG. The rig is worn to 3mm gap. Must I go on?? Oh the cylinder is 86.94mm top and 84.10mm bottom, the ports have been ground on the head and don't really match the cylinder.OK, I've got a couple of serviceable cranks, bought a std piston and head(ebay), a std ring, stub, bearings, seals and gaskets (Thanks John@Vintage Husky). I'm looking for a diagram of or any info on the switch from 5 to 6 speed, so I can make sure it's assembled correctly. The cases were plenty porous, a lot of welding was done but they look good for being early. I have most of the # for the trans parts but have no idea what they are from, any help would be great. Thanks Here's some pics.

Here's a couple more pics.

And the trans.

Hey mate, you might get more responses if you post your questions here.

http://www.cafehusky.com/forums/vintage-left-kickers.63/

Thanks 310 huskyTE , I posted it in vintage left kickers.

Ok, so I checked the 1973 mk/ml workshop manual and found the gears. The only difference is the 5/6 cluster and its mates. I've got the rest of the washers and spacers. Should go together . I bought the assembly tool from Joe at Jumbalya. I cleaned the cases and chased all the threaded holes and removed the cylinder studs. Found a marginal wall thickness under one stud boss looks like a crappy epoxy, will weld it sat. Then a final cleaning and bearings, a good masking and paint, then a bake cycle. Can't wait to finish this engine. Then I can disassemble the other and look for problems. Here's a pic of the epoxy.

Got It welded up and masked for paint, forgot to buy primer. Should have it by Friday. Dry fit the trans and found the shift return spring is really close to the end od the pin. I'm making a brass spacer to bring it a little further down the pin. I'll call John at husky restorations and see if he has a spring, this one looks a little twisted

Here's one with a temp spacer.

For the 6 speed to fit in 450 cases requires two case modifications. The mods have to do with the clearance of the step feeder and one of the shifting forks. Do you know if your 450 project has ever had a 6spd trans? Maybe the mods have already been made.

When I opened it, the 6 speed was in it. There is a grind on the lower left case where the step feeder is and it rotates without hitting the case. But I don't know what I'm looking for on the shifting forks, it does have the correct drum. What else should I be looking for? This bike has been full of surprises. I'm trying to straighten out the replacement crank too. What do you think about the spacer for the shift return spring. Thanks Crashaholic

Seeing you're putting a six speed in a 450 motor a valuable transmission upgrade would be to use the shifting drum and associated ratchet mechanism out of a late 70's magnesium motor. This will enable a quicker positive engagement of the gears. The stock detent pin and spring setup isn't near as positive leaving the gears to mesh slowly. The torque of the 450 is hard on the gears as it is especially if you're an aggressive rider so you want 100 percent engagement quickly. Also this upgrade reduces the required swing of the shifter level by almost half, another nice feature for this motor.

If you're interested in pursuing this setup I'd be happy to help you identify the necessary parts from a late 70's mag engine.

Its hard to make out whats been epoxied here, just make sure its airtight. Surely theres someone with a tig welder close by. Air leaks are a bummer.

The green spot with white on the left. I drilled it out and welded it with a spool gun, then wizzered the outside and polished the inside. I'll get a closer pic tomorrow. What do you think about the shift spring and a possible spacer? Is that spring normal all the way at the end of the pin?

Sorry I did not see your first reply. I can take pics of all the pieces I have for the trans. I Inherited this setup, weather it is right or wrong I cannot say. But I am ready to do what I can to use the 6 speed. Any info is helpful. Thank You Sir.

The shifter return spring looks fine and its placement on the stationary pin as seen in your picture is correct. The flat washer you added is not necessary. It is normal for the return spring to sit at the edge of the stationary pin.

Seeing that the motor had the 6 spd in it when you got it there won't be any need for the case mods I spoke of earlier. The previous owner would have done them to get the 6 spd to function.

As for the shifting drum I was referring to, its a later design drum from the late 70's 6spd. Take a look at the trans diagram I attached and you'll see the difference from the early 70's drum that you probably have. In the diagram you'll see a ratchet wheel #47 at the top of the drum. Its a better design in that it eliminates the possibility of getting the trans between gears, which is common when using the ratchet sleeve found with the early 70's 6spd drum. In addition to the drum you would need items 39 through 43. I often see this stuff on ebay for less than $50. It would drop right in with your 6spd trans. FYI: It does work with the 5spd but #43 requires modifications.

Thanks for the info, my setup is without those parts. I'll check on ebay.

Nice and easy, got the whole setup for 36.75.should be here by sat. That will give me time for the paint. so with this setup they are driving the drum from both ends? See your in AV, I have driven thru there a lot. Newport to Bullhead. And some time at Fort Irwin.

Haha, I had to look at the map, I meant Apple Valley, I'm get too old to remember...A lot. I've ridden out at Gorman, real nice area.

Still drives it from the bottom of the drum. The ratchet wheel on top of the drum replaces the pin and spring located on the bottom of the old drum.

Years ago I used to ride out by Fort Irwin. Nice riding area.

Well, no drum yesterday. USPS sucks for sat delivery, always the business is closed, no matter how many signs are saying the opposite. Anyway, I rebuilt the crank, got the pins from Wiesco, a little long so I trimmed them. and John at Vintage Husky supplied the bearings. My question is with chasing dial indicators, (It's been a loooong time since I've trued one). Do we get rid of the chasing first? I've got the crank between centers on the lathe, and a guage setup on each bearing point.