supercharged111
Member
Last night my sled received some long awaited triple pipes. Per SLP's attached instructions for 0-2000' I jetted with 147.5 in 2/3, but like Yamaha did a size bigger in the PTO with a 148.3 as I'm paranoid about blowing the thing up (again). I'm still waiting on 2 more weights in the mail before the clutching is all set to their spec as a starting point, but the sled felt like it was in the ballpark last night on stock clutching with an aftermarket mystery helix. The early tach can be really tough to see in less than ideal conditions. I am curious about a couple details on the installation starting with where does this spring that I circled go? There's nothing to hook to on the sled that I can see per the drawing and they don't call out anything in the instructions.
And how about these heat shields? What are they protecting?
I didn't get those heat shields as the pipes were purchased used. I'm sure they're easy enough to make, does anyone have pics of these and were these common pieces with all triple pipe sets?
I'm also missing the piece that went in the bellypan to hold up the silencer, I'll have to make that myself for sure as the silencer doesn't use any of the structure of the sled to hold itself up like the factory suitcase did.
I'll try and keep this thread up to date with my findings as I get it dialed in.
And how about these heat shields? What are they protecting?
I didn't get those heat shields as the pipes were purchased used. I'm sure they're easy enough to make, does anyone have pics of these and were these common pieces with all triple pipe sets?
I'm also missing the piece that went in the bellypan to hold up the silencer, I'll have to make that myself for sure as the silencer doesn't use any of the structure of the sled to hold itself up like the factory suitcase did.
I'll try and keep this thread up to date with my findings as I get it dialed in.
The reason Yamaha jetted the cylinders differently on the Red Heads was do to the three into one exhaust system and the stock airboxes flow characteristics. Having said that I found on our piped and ported SX triples it was safer to run the center cylinder slightly richer on the main jet.
With todays questionable fuels its always better[safer] to start a little rich on the main jets to start with.
With todays questionable fuels its always better[safer] to start a little rich on the main jets to start with.
supercharged111
Member
Did plug readings lead you to that conclusion? Or observing piston wash?
Plugs and wash were good but I was jetting for performance and we squeaked a center piston on a hard run so I jetted it up one size and never had a repeat. I always put it down to the center cylinder probably runs hotter do to location and coolant flow.
For info:
I just checked my notes and with the Bender pipes on a 700SX , and one layer of head gasket, I ended up at 150.0 mains on all three cylinders for safe trail riding.
I did run it leaner for snow drags.
I just checked my notes and with the Bender pipes on a 700SX , and one layer of head gasket, I ended up at 150.0 mains on all three cylinders for safe trail riding.
I did run it leaner for snow drags.
supercharged111
Member
Thank you for that. I'm not sure how much less the SLPs make than the Benders, I'm just trying to set it and forget it. Here is a pic after a WOT run where I hit the kill switch, locked the track, and skidded for a stop.
Do they seem like a light tan rather than a dark tan? Anything else I ought to be looking at?
From here I went back into the garage to attempt to ID my mystery helix. It's a Bender piece.
Not sure what to make of those numbers? Maybe a serial number? I started cleaning it up, going to get it nice and smooth then polish it. I have 3 new puck dealios to go in and I don't want to ruin them. If we can't ID this then I'll probably just go back to stock to see what that does, then get a 51/43 coming. Weights are supposed to show up tomorrow so I can see what they do too. I think it would be wise to put this helix back in and change only the weights so I'm not chasing my tail here. From down low the sled will zing out around 9000 RPM but once you get going it's back around 8500 max. Strange because it used to be more consistent than that, now it's doing what you had said stock clutching will do.
Do they seem like a light tan rather than a dark tan? Anything else I ought to be looking at?
From here I went back into the garage to attempt to ID my mystery helix. It's a Bender piece.
Not sure what to make of those numbers? Maybe a serial number? I started cleaning it up, going to get it nice and smooth then polish it. I have 3 new puck dealios to go in and I don't want to ruin them. If we can't ID this then I'll probably just go back to stock to see what that does, then get a 51/43 coming. Weights are supposed to show up tomorrow so I can see what they do too. I think it would be wise to put this helix back in and change only the weights so I'm not chasing my tail here. From down low the sled will zing out around 9000 RPM but once you get going it's back around 8500 max. Strange because it used to be more consistent than that, now it's doing what you had said stock clutching will do.
supercharged111
Member
According to this the mystery helix is a 49/45.
totallyamaha.net
So a 51/43 would be a step in the right direction if used with these stock weights. Would shift a smidge quicker down low and a smidge slower up top.
Bender Helix I.d. 3:16
MY INFO DON,T SHOW THIS ONE. ANYBODY 9970C 3:16 (yammie tony)
So a 51/43 would be a step in the right direction if used with these stock weights. Would shift a smidge quicker down low and a smidge slower up top.
Hard to tell from the pic but from what I see I would not go any leaner on the main jet...if anything I would go up one size. Coffee with only a little cream is the color you are looking for as well as the heat line on the ground strap electrode should be 1/4 to 1/3 from the base. Its almost impossible to jet a sled without actually being there with hands on but remember richer is safer and jetting to the edge only results in a small power gain.
That Bender helix's ramps are looking pretty worn...try an Apex/RX1 helix in better shape.
That Bender helix's ramps are looking pretty worn...try an Apex/RX1 helix in better shape.
supercharged111
Member
I thought the color looked a little too light, too much cream so to speak. I can stick 148.3 in across the board and get some 150 coming in the mail with a helix and maybe a couple engagement shims to try and cheat that RPM up a smidge. That left plug seems to have the most crust still sticking, is that heat line too far down? The sled is running BR8ES as they're more foul resistant. I made that decision in a vacuum eons ago and never bothered to see if the sled was happy with it.
I would go back to BR9ES plugs...especially with the pipes. Our sleds never fouled the BR9ES plugs. Old plugs don't work well for reading mixture as they dont really cleanup well to read mixture accurately. I bet you end up at 150 mains just like ours with the Benders.
supercharged111
Member
If I do, does that mean I'm making as many bald eagles as the Benders too? 
I cleaned up the existing helix today, looking a lot cleaner and the ramps are less beat up. But the one is still decently gouged.
Weights didn't show today either so that sucks. Hopefully I can get them in tomorrow. And in the meantime I'll get an RX1 helix coming, found a new one on eBay for $75.
I cleaned up the existing helix today, looking a lot cleaner and the ramps are less beat up. But the one is still decently gouged.
Weights didn't show today either so that sucks. Hopefully I can get them in tomorrow. And in the meantime I'll get an RX1 helix coming, found a new one on eBay for $75.
I run 147.5’s with my SLPs and with my Benders. 91 octane 1700 ft.
supercharged111
Member
I'm about 1100' lower than you are, I wonder what altitude sideshowbob is at? I remembered you saying you were at a 147.5 MH but forgot that Minot is where the altitude starts going up out west. I'm about 600' here.
I'm dragging from yesterday here, but thinking I ought to head up and rejet to the 148.3 that I have on hand, swap in some BR9ES, and go for another rip. I need to check the plugs at midrange as well, currently the rest of the carbs are stock only change was main jets. I believe it's pretty common to end up on stock pilots for a piped sled though, right?
I'm dragging from yesterday here, but thinking I ought to head up and rejet to the 148.3 that I have on hand, swap in some BR9ES, and go for another rip. I need to check the plugs at midrange as well, currently the rest of the carbs are stock only change was main jets. I believe it's pretty common to end up on stock pilots for a piped sled though, right?
With the Benders, before engine was ported, I was using 52.5 pilots, needles at position 3/4/3...700asl, modified airbox, one layer head gasket.
supercharged111
Member
I left the shelf in and drilled holes in it.
supercharged111
Member
Are my new rivets smooshed down enough? I pressed until they quit moving then pressed a little more so they mushroomed out.
They are shaped a little different. It looks like there will be less of a swing in RPM with the new weights as there's more meat down low than on the stockers.
Overall the mass looks to be more evenly distributed. So to pair with this I now have 3 known helixes:
A stock 45 degree unit, the Bender 49/45, and an RX1 unit I picked up today. I'm going to start with the 45 wound up to 70 degrees and the new to me weights as that's the baseline setting SLP calls for. Right after I stick those 148.3 jets and BR9ES plugs in.
They are shaped a little different. It looks like there will be less of a swing in RPM with the new weights as there's more meat down low than on the stockers.
Overall the mass looks to be more evenly distributed. So to pair with this I now have 3 known helixes:
A stock 45 degree unit, the Bender 49/45, and an RX1 unit I picked up today. I'm going to start with the 45 wound up to 70 degrees and the new to me weights as that's the baseline setting SLP calls for. Right after I stick those 148.3 jets and BR9ES plugs in.
I think you need to peen the rivets down a bit more so they are flatter more like the originals. Place one side of the rivet heads on a flat solid surface like a vice then hammer the other end down to be flatter.
supercharged111
Member
Is a hammer preferred over a press here?
Unless you have a very strong press a hammer is usually the tool of choice for this...old school riveting...buck and rivet. We used a bucking bar and hammer type air riveter on Float plane float repairs back in the day...and that is probably still the technique.
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