VMAX to 1st Gen MK2 swap?

[Grisolm1]

Thinking about looking for a crashed VMAX to begin a swap to my MK2. Figure having the whole bike would be better than buying pieces.

 

Anyone done this? Were you happy? What are best year VMAX's to look for? Will stock collector just strangle this thing?

[dingy]

I did not do an entire Vmax engine swap. The Vmax will however fit right in.

 

I used the bottom end out of a 1988 Venture, which is a 1300cc compared to a 1200 Vmax. This is what the Vmax guys are doing to get more HP.

 

The top end from a Vmax will bolt right up to the 1300 lower end. You want to use 1300 head gaskets. Exhaust headers are a match.

 

The main problem is getting the V-boost system to fit in. It can be done though. Requires modification to air cleaner. Choke is different on Vmax carbs, hand choke on carb body instead of on handlebars.

 

In my humble opinion, the collector is not that much of a restriction compared to the mufflers. From what I could see in the collector, there was only one internal 'swiss cheese' baffle. By shining a light in the intake I could see lots of light through the muffler port. The mufflers are a huge restriction.

 

Gary

[Grisolm1]

Thanks Gary

 

Are the valves/ports different on the Vmax heads vs Venture 1300. I know the cams and valve springs are different.

 

Did you get the vboost to fit yours?

 

Mufflers! We don't neeeed no steeenking mufflers!

 

Just kidding, but one of the most awesome sounding bikes I've heard was a built Vmax with aftermarket pipes. First Japanese bike I felt like I could have a passion for. Sounded like a NASCAR engine. I was real happy when I discovered that the same heart has been hiding all these years in a bike my wife would ride for more than 20 minuites.

 

Yamaha probably would have sold a bunch more if they advertised it properly, er, make that at all. I've been into bikes for most of my life and only recently discovered the joys of 1st gen ownership. Truly an under-rated versatile ride with huge upgrade potential.

[dingy]

Valves are different on Vmaxs.

 

Stem is 1mm smaller dia..

 

O.D. of valve head is 1.5 mm larger.

 

This gives the engine more ability to pull air in and push it out.

 

One of the differences I have seen on mine with the Vmax heads is that I am now running with four 7/16" dia. holes in the air box lid.

 

With the stock 1200 engine, it would degrade the engine performance with just two 7/16" holes.

 

I can't say how much the air holes are helping if any, but they don't seem to hurt.

 

Putting the extra air in the bike tends to lean it out, and most ventures are running lean on a factory setup.

 

I have tweaked carb jetting some to overcome lean running.

 

I have not put a v-boost on as of yet. Maybe this winter.

Gary