Yamaico's new el Cheapo Project.

[yamaico]

pete/firko
can you tell me what the front wheel is and brake plate
cheers
jim
ps its looking good did you get the softwere sorted out

Software is all sorted, thanks Jim.

[firko]

Pete just had a good bit of luck with finding a 'special' YZ400F engine..I'll let him explain.........

Just talked to a mate who’s CR250 engine I’m rebuilding and he casually mentioned that he has a complete YZ400F motor in his garage that I can have. The motor actually came out of a bike that I rode in the Nepean 6 hour in 1981. I was riding and we were in second place on the same lap and closing rapidly on the leaders with 15 minutes to go when the piston seized, which I believe was a result of the pit crew forgetting the oil in the fuel for the last pit stop. Anyway, he ended up with the bike and took the engine out for some reason and the rolling chassis got knocked off from his garage, so the engine has been sitting under his bench for the last 30 odd years. I’m gobsmacked that I will end up with it. Wish he had told me this a month ago before I started on the CD project bike. Looks like another el-cheapo will be in the makings. Might stick it in a ? frame and make a serious racer out of it. Oh, the mind boggles…

[bazza]

Come on Firko you know its going in a Hindle frame

[firko]

Bazza....It's not my project :'( and as much as I like Pete, he's not getting one of my precious Hindalls (yet). Moving on....
Well, my cylinder is still in LA somewhere, so I’m hoping it’s not lost. Almost running out of things to do so I made the new chain guide side plates and the muffler housing and end cap. I don’t have a magneto cover so I might make one of them next. I mounted some oval number plates for the side numbers but they look a bit “add-on” so I’ll probably think about making some sidecovers as well. I’m going to leave the airbox until the pipe is finished, so there’s really not a lot left.

[JC]

Pete,

I reckon there's a Maico frame (AW?) just begging to be a new home for the YZ400F engine.

A pre78 Yamaico would be nice company for yr pre75 one.
(Edit: or would it need to be a Magnum frame to be correct era for the 400F engine??)

Lovely work on this project too.  Wish I had quarter of yr talent!

[firko]

I reckon there's a Maico frame (AW?) just begging to be a new home for the YZ400F engine.

An updated version of Pete's original Yamaico. I love it! (apologies for the crap scan and photo, it's the only one I've got)

[yamaico]

Pete,

I reckon there's a Maico frame (AW?) just begging to be a new home for the YZ400F engine.

A pre78 Yamaico would be nice company for yr pre75 one.

Lovely work on this project too.  Wish I had quarter of yr talent!

You're right John, an AW would be perfect. I'll have to start scouring Mark's swapmeet for a rolling chassis.

[firko]

I couldn’t do much on the bike on the weekend so I soda blasted the cases, and they’re now ready for painting. I was at a good mate of mine’s place on Sunday that used to own a bike shop and he donated a set of fork seals. He had a box full of different sizes that have been sitting on a shelf for years, which I’ll keep in mind for the next project. My cylinder turned up yesterday and it’s in great shape. I bought it from Mike Bolde from Mark’s Swapmeet, who is a really good guy to deal with. It was just as he said it was and he even painted the head and cylinder. The piston has very little wear and the bore is good but it could probably do with a set of rings, which he told me. Last night I made a rough mock-up of the exhaust out of cardboard to check the fit and it looks OK so tonight I’ll be developing and cutting out a whole bunch of little and big cones, ready to weld together. I’m at around the $850 mark at the moment but I still have to get some muffler packing, the seat covered and whatever else so I’m probably going to be a little over the $1000.

I have to go back to Indonesia at the end of the month for 3 or 4 weeks so I want to get as much done as possible between now and then. I’d really like to get the pipe and airbox finished and the tank and frame painted before then so I only have to do the final polishing, powdercoating and assembly when I come back.

[vmxrider]

Looking good Yamaico.
What size compressor do you use for soda blasting? I've done some very small pieces using one of those cheap 2HP (122L/min) compressors but its bloody noisy and barely keeps up. Thinking about upgrading without going overboard.

[yamaico]

Looking good Yamaico.
What size compressor do you use for soda blasting? I've done some very small pieces using one of those cheap 2HP (122L/min) compressors but its bloody noisy and barely keeps up. Thinking about upgrading without going overboard.

I've got a 13cfm compressor and it struggles a bit. That's the only problem with the soda blaster  - air consumption. I have found that it works well on 70 psi, which makes it a bit easier. It's a handy thing though, as it doesn't damage seals, rubbers, plastic etc. and is really good on things like carbie bodies.

[vmxrider]

If you're struggling at 13cfm then mine is way off at only about half that. Might just get another cheapy and connect both together in parallel when blasting.

[firko]

I took advantage of the sun yesterday afternoon and painted the cases, so as soon as I get the seals and gaskets I can put the motor together. I found an old set of cases in the stash that I am using for the mock-up, so the good ones don’t have to go in until last. Started making the header pipe last night and noticed the exhaust flange was only 42mm, with the exhaust port being 45mm, so I had to remake the flange first. Finished that and then made some of the header pipe and hope to finish it tonight. I have never made an up-pipe before, they are really fiddly and take ages. Took about 4 hours to make nine little cones and weld them together. Once I get the header going in the up direction the pipe only needs one more major change of direction at the head and then it’s just minor fit up from there. I have to cross over to the other side of the bike so I need to keep an eye on the carbie top to make sure I have enough room for the throttle cable to clear the pipe.

[firko]

Got most of the pipe finished yesterday, just the baffle cone and stinger to weld on, and a couple of mounting brackets. Tucking it in under that skinny little YZ tank was testing, but it's pretty much out of the way of the left knee, and clears the plug cap and throttle cable, so it should be OK. Stripped the forks in between welding the pipe and bead blasted the legs, replaced the seals and put them back together. I was going to polish them but they looked good after I blasted them, so I left them that way.
By the way, if anyone wants an up-pipe built just give me a call - and I'll give you Geoff Morris's phone number. That wasn't a lot of fun at all.

[Lozza]

That pipe looks mighty short, I hope you didn't use any free online pipe design calculators? Nice work on it just the same.

[yamaico]

Thanks Lozza. The pipe is actually fairly long, but I went down a fair way and back up with the header to use up a bit of length so the pipe didn't stick out the back too far. I certainly don't use any of that free software (did a check against one of my pipes once and it was nowhere near it and about 150mm dia. in the belly!!), I'm a bit old school and still use Bell's book. My brother John is a real whiz with that and he usually designs my pipes (he built a '73 CR250 roadracer years ago and it was a rocketship). The 465 flat track bike's pipe were dimensions that Geoff Morris was kind enough to give to me and after checking they were very close to what would be generated from Bell's formulae, and it's no slouch. I had a guy give me a "super very fat design" for my Yamaico once and it was significantly slower than the Bell pipe that John designed,
Cheers,
Pete.