Upon taking it apart I am finding a few problem prone areas that need attention for sure, you can see the mag side piston was cracked at the rear skirt, this is from never having rings put in it over its 6900mile life and the skirt has rocked back and forth in the cylinder and began to stress and crack the skirt. You can also note the brown blow by on the piston from the rings down where your getting blow by into the engine,losing power there as well. I will repalce both pistons with new yamaha oem pistons and have the skirts coated at swain tech. The newer yamaha pistons already come with the modded rear skirt to advance the intake timing, I will also address more timing change on the cylinders themselves when we get to that point.
I also always look at the fan belt on these phazers they are also prone to destructing over time, this one will be replaced.
Heres a tip for easy little power gain, you see how the stock reed stops are shown, by carefully opening these up a little bit you will gain a little extra power by allowing the reed to open up a bit more, this doesnt ruin the reeds as your only gonna add around 3-4mm of space. You must bend the stops evenly,go slow and keep measuring, here the phazer stops are just about 27mm, I will make them 30.5mm.
I also always look at the fan belt on these phazers they are also prone to destructing over time, this one will be replaced.
Heres a tip for easy little power gain, you see how the stock reed stops are shown, by carefully opening these up a little bit you will gain a little extra power by allowing the reed to open up a bit more, this doesnt ruin the reeds as your only gonna add around 3-4mm of space. You must bend the stops evenly,go slow and keep measuring, here the phazer stops are just about 27mm, I will make them 30.5mm.
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You can see yamaha didnt spend alot of time blending the cylinder to the cylinder liner, they are pretty crude from the factory, we will address this and make good smooth contours in between the 2 differnt parts. theres a bit of work to do on the bottoms,exhaust port and rear intake port on a phazer, more on this soon.
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YooperWoods
New member
Sweet build and cool tip on the reed stops thanks. I believe I read here that you are the master of porting. I'd like to send you my cylinders either over next summer or with the two extras I have here, those will need to be bored and honed also. I cleaned up the bottom of my jugs too as they were even more crude than yours but I didn't have carbides that small to do a really good job. Most of the porting I've done has been on small block chevy's.
lowered the front suspension down this afternoon, simply built a set of spacer tubes to let the strut tube go further up into the spindle,this way I dont have to cut the springs and make them too stiff. I used a 3.5" of tubing and welded it to the stock cups, only instead of putting the cup on cup it has a spacer in betwwen allowing the spring to go further down,lowering the sled. I kept it at roughly 2.5" of travel. I also shortened up the bump stops so it will not hit before the 2.5 travel, just cut them off with a hacksaw. Heres a couple pics for those who dont know whats under the strut can covers.
I am going to machine the ski mounts next to install srx ski mounts with viper plastic skis on it, but I need to get another srx ski saddle.
I am going to machine the ski mounts next to install srx ski mounts with viper plastic skis on it, but I need to get another srx ski saddle.
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no problem get ahold of me when your ready, youll see everything I do to them in this thread. When done they do really rip for a little engine! You have been doing a great job on your sled, I have been watching your thread. You got the good pipe too!
Yamaha Nutz
New member
trying this from my phone but mine is just about done
oh, i like the seat and tank set up, that would for sure allow you to move easier and get hung out on the inside with ease, whats that tank from?
Yamaha Nutz
New member
Not Yamaha .........lol It is a 76 MERC liquid Sno Twister tank ...the seat I carved and covered myself
YooperWoods
New member
What is that hood windshield combo from?
Yamaha Nutz
New member
hood is 92 venture gt windshield is a venture windshield that is cut down sorry Mr viper not trying to stealThe thread
Very cool!!
forgot to add this for the engine part, I figured up the engine for piston timing to the cylinder, if you remember it was off quite a bit and the piston overhung the transfer ports and the exhaust port so it needed to be spaced up. I came in at .031" thick base gasket got it about perfect in the main exhaust floor and the transfer ports. So if you add distance to the bottom youll need to cut that off the top or youll add all kinds of deck clearance. You can see in the pics how much better everything lines up, so its not a giant amount and wont advance the timing on the transfer ports to ruin the engines low and mid range power. I will check it next with degree wheel both ways with stock base gasket and thicker set up and see where its at.
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So I had a bit of free time for myself today so I removed the suspension and track assembly to get ready to install the new track i got for it. It was definitely time for the suspension to come out and gone over by the looks of all the wheels...lol, check out the pics, nice idlers and idler shaft wheels..lol! I will replace all them and pull the skid down via the limiter straps. You can see the differance in the track thickness of the old vs the newer yamaha track.
I removed all the outside picks from the track so it has 96 down the middle which is more then enough for a phazer. It should help the rotating weight out going to the lighter track.
I removed all the outside picks from the track so it has 96 down the middle which is more then enough for a phazer. It should help the rotating weight out going to the lighter track.
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I also pressed off the drivers as they were well worn on the front sides, I simply pressed them off and flipped them over to use the new never run on side. I will turn them in the lathe tommarrow to true them up. When you press drive sprockets off always be sure to pay attention to the timing marks on them as shown in the pic. These arrows must point to the same flat on the axle so they are aligned with each other, and you must pay attention to the spacing from the ends of the shaft. I also check the drive lug spacing on the track I am using and make the drivers fit that perfectly so its not rubbing on the sides of the lugs scrubbing off speed.
So now I am removing bearings in good wheels and cleaning and greasing them and installing new wheels where needed. I am using my own blend of light grease and axle lube blend, it really frees up the bearings. This is NOT something I would do for trail sleds but for race sleds it works great and reduced friction.
So now I am removing bearings in good wheels and cleaning and greasing them and installing new wheels where needed. I am using my own blend of light grease and axle lube blend, it really frees up the bearings. This is NOT something I would do for trail sleds but for race sleds it works great and reduced friction.
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Post some pictures of that RPC single pipe !!
Any pictures ?
What is the maximum track lug height you can put in the Phazer/Venture chassi:
* With 8-teeth drivers ( 2,52" pitch ) ?
* With 7-teeth drivers ( 2,52" pitch ) ?
I'm not to happy about going for a smaller drive sprocket since it messes up the tracks approach angle against the snow.
...yes you could mount the skid in another position,
but that gives the sled longer "wheelbase" and that is not good for the riding enjoyment and the handling of the sled.
Post some close up pictures of your sled.
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MR. V, any updates on this project?
I would like to know a bit more of your piston modification and wrist pin.
If the Phazer-IV 14" track is of single ply construction there is probably no problem to bend over a 7 or 8 tooth drive sprocket.
Tell us more about this mod !
The old school 2-ply tracks with Nylon cord is not good when using 7, 8 or 9 tooth drive sprocket.
The new type of 1-ply tracks with Kevlar cord has minimum problem with smaller drive sprockets.
What are minimum squish clearance with 91-Octane fuel in the Phazer-480 engine ?
Where can you order this Cometic gasket ?
Yamaha part # ?
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tjsands12
New member
are you interested in selling the DG pipe??
There will be updates very soon, I have dug it out and have all the parts needed to finish it. Just gotta get off my butt and finish it, always something else in the way.....lol
No, I need the pipe for the sled.