Grizzly manifold

[dandywarhol]

Can anyone confirm if the Grizzly inlet manifold is a direct fit onto the 5 valve 660 head?
Thanks in advance, Alan

[edfmaniac]

I'm pretty sure there isn't any single carb OEM manifold that is a direct bolt on. The bolt pattern on the Grizzly manifold isn't even close according to the pictures I just looked at on Google.

[edfmaniac]

Also there are multiple 5 valve heads for the Yamaha 660. Make sure you are talking about the 3YF head. The Grizzly head is different not only in the manifold area, but I noticed a few other differences immediately.

[dandywarhol]

Thanks. So I suppose the answer would be to make an adapter plate to mount the manifold and then additional holes to line up to the head?

I really can't justify the cost of both larger downpipes and scarce 33 mm carbs, so I was looking at abig single carb.

Would anyone know if the MZ downpipes are a different diameter than Yamahas SZR ones?

Thanks again in advance
Alan

[edfmaniac]

Is downpipe Scottish for exhaust header? The MZ is definitely different than the SZR.

Now I'm curious why you are interested in switching out the stock headers and carbs. They are quite sufficient unless you are wanting to do some major head work. You won't see any gain in performance over the stock equipment until you start putting in high lift cams. What is your goal?

There's a company in your area that builds headers for the MZ Skorpion but they aren't cheap. Projection Components.

[dandywarhol]

Downpipes = headers.
My goal is to try to extract 10/15% horsepower to use both on the road and track. I had a trackday 2 weeks ago and was v. Impressed by the handling and composure on a fairly smooth track.
I have a spare head which I can lightly port/ clean up. I don't think I need to go down a big valve route, there's plenty surface area with the stock valves IMO for what I want to use it for. Ive noticed the MZ and SZR have quite different downpipes but don't know about diameters. The SZR pipes are also shaped around the oil tank.
My thoughts are that better carburetion, free flowing exhausts and maybe a cam re profile would give me what I'm looking for. I have an Ignitech ecu on my Yamaha TRX and I'm impressed with the quality and endless permutations available if modifications are done to anything on the engine.
I've also poured over Bill Jurgenson's stuff but don't want to go that far.
Anyone's personal experiences would be appreciated

[edfmaniac]

You should be able to reach your goal without doing anything other than cleaning up the intake and exhaust path throughout the engine, putting in a mild cam and programming the spark control unit effectively. Also remember if you want to run at sustained high rpms, you need to address the decomp mechanism failure and the cush drive sprocket in the balancer gear drive train. Both are easy fixes.

The stock intake boots and intake ports on the head can be cleaned up quite a bit. Adding one of the many Raptor660 carb intake spacers on the market will give you a good way to match the ports and will lengthen them a little for extra torque. Also, when you get into porting, run a drill bit down the crossover port between the left side and right side that is 3 or 4mm bigger than the existing port and clean up the edges. Then check the weld on the headers, the ones near the exhaust flanges and the joint where the down pipes meet the mid pipe. You should easily be able to get the power you are looking for without spending money on carbs and headers. According to Bill J, the single best thing you can do to these bikes is getting rid of the wheels, and of course that's the last thing on my list. I want expensive ones so I'm waiting until the project is almost finished to give myself the motivation to spend that kind of money.

[edfmaniac]

Just in case you were wondering, I put down almost 60hp with slightly modified stock carbs. They can definitely give you 10-15% over the stock hp rating.

[dandywarhol]

Thanks. I know about the balance shaft woodruff key problems but not about the decompressor. I'll try search.
So, stock carbs with the secondary one coming in a bit earlier you think?
On stock gearing it was reaching 7200 rpm in 5th and comfortably staying with a well ridden VFR400 NC30. Better breathing should give a little more torque and power without raising the rev ceiling too much more.

Our posts overlapped! Bill J is so right, improve the power to weight ratio and you keep reliability. The SZR has a light Brembo wheel in the rear and a light(ish) Yam TZR125 and light Brembo brakes up front. I know Kayla of Projection Components but even 5% discount these pipes are still expensive but nice

[jaywillie2912]

I have a 2002 Baghira which will be used on the highway....

I want to use a Lectron carb which would require a Grizzly manifold... and would also upgrade the header...

While I have you here.....what would you recommend as far as a stage-2 cam system.

Thanks,

Jaywillie2912