How effective is removing fan blades on the old Exciters to increase hp? Optimal number to remove? Thanks!
Brad_69
New member
Fan blades Removal
The problem with removing the fan blades is the over heating & eventualy burning up the pto cylinder. to gain the best HP, I would smoothem out the ports. If you can make them as smooth as posible. That would do the trick. I know some more tricks to boost the HP on those old Exciters. I currently have a 78 & 79 Exciters. Brad
The problem with removing the fan blades is the over heating & eventualy burning up the pto cylinder. to gain the best HP, I would smoothem out the ports. If you can make them as smooth as posible. That would do the trick. I know some more tricks to boost the HP on those old Exciters. I currently have a 78 & 79 Exciters. Brad
Thanks, Brad...I'd love to hear more. Unfortunately, these are vintage racers & porting isn't legal in our race series. Thanks!
Brad_69
New member
Cleaning the ports up isn't what I would call porting. I would match the cylinder gasket with the crank case & cylinders. so there is no extra gasket inside the transfer ports. Brad
MountainMax
New member
exactly, porting is when you change the port timing, and boring out ports, just a clean up works well, I dont that on my old enticer 340 and it made a noticible difference...
Brad_69
New member
I know what you mean. I have a 78 Exciter 440 and polished up both intake & exhaust ports and also the transfer ports. I have to do quite a bit of rejetting ( reading plug color). My Exciter is one fast mother. When I was rebuilding the engine I matched the cylinder gaskets up (cylinder to top engine case). That way their is no gasket material the protrudes into the transfer ports.
How effective is cutting down the y-pipe? How far?
MountainMax
New member
I have a bullitin from yamaha on this mod, something about opening up the restriction in the y-pipe, hmm now where did I put it???????/
maxx0770
New member
if you could find it that would be great. i am trying to figure out what to do with the exhaust on this thing. i have never heard of this particular mod though. Rob ill get you pics of that bumper soon.
MountainMax
New member
Looks like in 78 and up they put a restriction in the pipes, the 77's dont have it, it was meant to improve fuel economy, if you cut them off and grind them to full open again it, then reweld them, it should gain you some HP, you will have to rejet after this mod though.......
or if you can find a 77 one use that, the pic below shows a 77 one ont the bottom left, and the 78up one on the bottom right.
or if you can find a 77 one use that, the pic below shows a 77 one ont the bottom left, and the 78up one on the bottom right.
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