"TurboMax" Build with Pictures.

[Vespa]

Bike: 1981 Yamaha Maxim 650.
Parts from: 1983 Yamaha Seca Turbo 650, Harley Davidson Sportster, Yamaha VMAX, Suzuki GS1000

[jlgace]

Way to come out swingin'.  Can't help but notice the posture of the bike when you've got it strapped down to the lift.  Just my taste, but I'd run with that.  Little bit of that nose-down drag bike look...

[Vespa]

Thanks. The "rake" has yet to be set. Couple things have to be worked out. Not sure I'm a big fan of the air shocks. May go with a set of progressive shocks I have on hand. The front is completely adjustable. They are currently in the highest position until the Lockhart Oil Cooler is installed. Could be a fender clearance issue when weight is on the bike with lower stance. Plus the return oil line has to be lower at the pan than the turbo to keep oil from getting backed up into center section and going out the exhaust. On the Seca, those were taller in stance and was engineered that way for a purpose I guess. To keep the turbo off the ground. Lol

[Vespa]

My thought on controls and the dashboard will be simple. I have a Set of VMax throttle and electronic controls. The dash will be a simple GPS operated Speedometer and a Handle Bar Mounted Boost Gauge. 15psi is what I'll be shooting for. This engine has been doing 12 psi without issue in the stock chassis. This bike should be much lighter. Might be a bit of a handful for a one legged old man.

I had intended to use a complete R1 inverted front end and a VMAX Rear section for this build but when mocked up made the bike too bulky.

[jlgace]

Can't say that didn't cross my mind about the turbo underneath.  A little bash plate might be worth it.  A word of caution about your boost: from what I've seen in turbo'd snow machines I would go easy bumping up the psi too much.  12 seems to be a nice, happy place for them.  Seems like every psi after that results in a commensurate decrease in reliability/engine life.  You need very consistent fuel quality with adequate octane and the room for error shrinks with more cylinder pressure.  Not sure what the compression ratio is on your bike, definitely in your favour it was built with a turbo on it in the first place.  I admire you taking on the challenge.  Don't see many home-built turbo machines out there. 

[Vespa]

The engine turbo and plumbing is from a turbo Yamaha Seca. In 1982 the bikes were released to operate at 6 psi. In 1983 Yamaha came out with an upgrade kit that bumped the operating pressure to 12 psi. The cool thing about the system is that Yamaha built a fail safe into their own system. The Plenum (behind the carburetors) has a trap door that opens at 15psi. So not allowing the engine to over boost over what they engineered it for. As far as the driveline goes for this build I'm just transplanting an already engineered induction system into a different model motorcycle frame.

The right side muffler isn't a muffler at all. It's the wastegate. Look close. The smaller the hole in the end of the right muffler is how Yamaha designed the amount of boost. The smaller the hole the higher the boost upto 15 psi. The bike will probably end up with just the left side exhaust and a plate over the wastegate hole at the turbo.. 12lb weight savings not having the extra muffler.

[Vespa]

Too add. The fuel system is done with an electronic fuel pump and a vacuum operated FMU that increases the fuel mixture just like automobiles use on turbo carburetor and most fuel injected engines.

[two-smoker]

I often thought about putting a Seca Turbo topend on a Radian or FZ600 motor... I really hate shaft drive....
But I digress. Not a bad start.

[Vespa]

[Vespa]

My 14 year old son sitting on bike

[jlgace]

She looks good.  And I say that as a person that's always had trouble accepting the combination of a cruiser with an inline 4.  Particularly like the wheel treatment and black is going to make it work.  Looking forward to the finished product. 

[Vespa]

If I had my choice I'd be building a twin or another triple. But when I had 3 of these turbo engines and a Maxim frame laying in the corner it was inevitable I was gonna build it. Low key is what I'm after as far as appearance. I won't tell anybody what it's made of so I can hear their gasps when they see the hair dryer on my cruiser.

[Vespa]

Tank is done. Correct fitting for Turbo petcock welded in. Tank Powder coated to match fenders and exhaust. Black Wrinkle.
Also found my speedo. $30 Garmin Nuvi off Craigslist. 2011 update is good enough. Didn't get for the GPS anyway. LOL

[Vespa]

Finished the Turbocharged Maxim Last Week.

Pictures of Finished Bike:






Judges at Sons Bike Show must have liked it. I gave him the keys to his new motorcycle at the show.

[DesmoBro]

^Awesome^ One Bad Ass bike

[Rich Ard]

I'm pretty sure at 14 I woulda crapped my pants. Nice job man.

[Vespa]

Thanks Gentlemen.

He was excited. He's a good student, plays sports and band. Plus next Year he will be Playing Professional Paintball. he works full time during the Summer. Just couldn't ask for a better kid. He helped with a lot of the project and made the push to get it finished.

I also won the Bid on a VMAX in and Insurance Pool so I need the room anyway.
Watch for that build with some of the same looks as the Maxim

[jlgace]

Looks good.  Like the stance.  You make me feel like a hypocrite.  I'm not sure I'll ever hand my son the keys to a bike.  He's too much like me.