Guess you guys have waited long enough to see this...Turbo charged, 151" exciter.

A little off topic.....

crimsonride said:
Lasse is right.
You're bringing up the front radius of the track when you switch to 7T drivers and lowering the "on ground" front portion of the track...
makes for a less than desirable approach angle.
I'm not sure how much this affects you guys but here in the west it kills us in the deep snow.
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;)! Exactly, That is the end result if your approach angle is to step !

prankster said:
My switch to 8 tooth drivers will probably include some adjustments too.
Lasse stated earlier an angle between 17-19 degrees.
That's what I'm going for.
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:arrow: Drivers diameter with 2,52" pitch:
7T = 5.50"
8T = 6.25"
9T = 7.05" -------> Stock on Yamaha Exciter-I/II
10T = 7.85"

- - - - - - - - - - - - - - - - - - - - - - - - - - -

REMEMBER:
When you go down the diameter of the drive wheels,
you get worse attack angle against the snow.
Which is not good from a get through the snow standpoint.

You can however somewhat adjust/compensate this by moving the skid backwards.
Always aim for a 17-19 degree attack angle against the snow !



:2strokes:
 
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Nice build. IMO your motor is still 88 or older, it will need extra mass added to the flywheel and cooling opened up to the case under the exhaust port. Thats why I asked about motor mods
 
crimsonride said:
I ran it with the turbo for just a few runs at 4 psi... the old turbo system that I found had a "analog" system...it basically boosted to four PSI and then kicked in an extra four PSI of fuel pressure.... this basically meant if you weren't at full boost you were either lean or rich. I've rebuilt the fuel system with a linear system with a boost referenced fuel pressure regulator that will maintain a 1:1 fuel pressure increase with the boost. I will be running it at 12 PSI boost. I fun straight 114 race fuel in my other sled so I'll probably just run that in this thing.

It's an Aerodyne Turbo... one of the old variable vane style ones. Hopefully it doesn't burn out too quick.
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Extra fuel pressure sould not make your motor go rich. It's likely your needle and seat are not holding and making it go rich. Use a pop off checker to test what pressure it will hold. I can turn my fuel pump on to 20lbs of fuel pressure no boost and it runs the same. I can turn it on with the motor off and it wont flood. All it should be doing is keeping the float bowl full of fuel. Also I'd bring your spark plug gap down to .018 with 12lbs of boost
 
toydoc said:
Nice build. IMO your motor is still 88 or older, it will need extra mass added to the flywheel and cooling opened up to the case under the exhaust port. Thats why I asked about motor mods
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Doc. The motor is a 93. Other than new pistons and cleaned up cylinders nothing else done. What would you recommend? I've changed my plans for the heath exchangers....Home made U-cooler coming up.
 
toydoc said:
Extra fuel pressure sould not make your motor go rich. It's likely your needle and seat are not holding and making it go rich. Use a pop off checker to test what pressure it will hold. I can turn my fuel pump on to 20lbs of fuel pressure no boost and it runs the same. I can turn it on with the motor off and it wont flood. All it should be doing is keeping the float bowl full of fuel. Also I'd bring your spark plug gap down to .018 with 12lbs of boost
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Doc. There were other things going on other than just the fuel pressure not rising with boost. It also used the old pulse pump and had jetting issues. It also had no power jets so I had no way of adjusting AF ratio on the trail with elevation change.
 
crimsonride said:
Doc. The motor is a 93. Other than new pistons and cleaned up cylinders nothing else done. What would you recommend? I've changed my plans for the heath exchangers....Home made U-cooler coming up.
Click to expand...

Cool, your good on the motor. That has all the updates if you use the 93 flywheel.

What ign / cdi are your using, 93?
 
crimsonride said:
Doc. There were other things going on other than just the fuel pressure not rising with boost. It also used the old pulse pump and had jetting issues. It also had no power jets so I had no way of adjusting AF ratio on the trail with elevation change.
Click to expand...

Without seeing what you have I'm just putting out what I have used or would use. I keep pulse pumps, plus elec that turns on from a normally open hobbs switch. Then a regulator set to 10lb more the boost pressure. The needle and seat sometimes don't hold (thats why I test with a pop off), so I install Grose Jets. They hold 20lbs without issue. Install your power jets and don't cut them down. Start at 100 powerjet.

The carbs do the adjusting of AF, turbo or non turbo. They don't know what they are bolted on, they just feel pressure and vac. So make sure you have a good needle and seat, power jet, float bowl full of fuel, float bowl vents run to the air box. That carb has to "feel" the same pressure in the bowl, on top of the slide as it does at the inlet / bell mouth.

Jet the carb to what it would be for a stock 93 (using 93 carbs). Make it run good without boost. Then add the PJ, start at 100. Keep the boost 6~8 lbs for now and see what it looks like.

When you use fuel pressure to adjust AF, you over running the carb and what it was made to do. IMO, that may give you more problem later
 
toydoc said:
Cool, your good on the motor. That has all the updates if you use the 93 flywheel.

What ign / cdi are your using, 93?
Click to expand...

I'm almost positive that I am. I'll have to check when I get back in the country. I'm in the Dominica Republic right now.....not much snow here. :)
 
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