so you’re saying you actually mated are heads to run single carb?
VT750 ACE Camshaft Change
Due to hot weather baking my shed and family stuff my "two day" project dragged on for a month.
But now it is finally up and running with valve springs and cams from a NT650 Hawk GT.
It now finally feels like a 750 did when I was a kid, it feels like a different engine.
I have not swapped out the exhaust yet, but I'm sure it is a bottleneck in the performance at this point.
I put Uni pods on the carbs, and followed along with stretched and heat treated slide springs to stop the slide flutter and fuel spray that is usually the nightmare of such installations. Slow jets are 42, main jets are 140 front and 145 rear and the Dynojet jet needle is on the second notch. The plugs look OK, but I'm going to have to go richer still with an exhaust change. My rev limiter is set to 6800 rpm that it hits readily in second and third gear, didn't want to cover ground faster than that while sorting it out.
Things I have learned:
I changed the valve springs without pulling the heads, making your own valve spring compressor is a pain, making 3 for different locations is worse.
I would probably pull the heads if I was doing it again even though I had good compression, despite what the manual says it can be done without pulling the engine.
Just for entertainment, stock intake springs you can remove with your thumbs, just grab the keepers with a magnet!
I almost forgot the most important thing: If you use a 4mm wrench when setting your valves tie a couple of feet of string to it. Those things are tiny and if they have a long tail it is harder for them to disappear. "Ah ha I've got you", is way better than "WTF did you go".
NT650 valve covers fit the VT750 although you lose the place for the secondary air cleaner and the crankcase vent is just a hose connection of the rear one and is noisy.
As the bike is now it only takes unplugging the spark plugs and four bolts to remove the covers to check the valve clearances.
I have attached a picture of how it looks with no added trim.
![282334]()
But now it is finally up and running with valve springs and cams from a NT650 Hawk GT.
It now finally feels like a 750 did when I was a kid, it feels like a different engine.
I have not swapped out the exhaust yet, but I'm sure it is a bottleneck in the performance at this point.
I put Uni pods on the carbs, and followed along with stretched and heat treated slide springs to stop the slide flutter and fuel spray that is usually the nightmare of such installations. Slow jets are 42, main jets are 140 front and 145 rear and the Dynojet jet needle is on the second notch. The plugs look OK, but I'm going to have to go richer still with an exhaust change. My rev limiter is set to 6800 rpm that it hits readily in second and third gear, didn't want to cover ground faster than that while sorting it out.
Things I have learned:
I changed the valve springs without pulling the heads, making your own valve spring compressor is a pain, making 3 for different locations is worse.
I would probably pull the heads if I was doing it again even though I had good compression, despite what the manual says it can be done without pulling the engine.
Just for entertainment, stock intake springs you can remove with your thumbs, just grab the keepers with a magnet!
I almost forgot the most important thing: If you use a 4mm wrench when setting your valves tie a couple of feet of string to it. Those things are tiny and if they have a long tail it is harder for them to disappear. "Ah ha I've got you", is way better than "WTF did you go".
NT650 valve covers fit the VT750 although you lose the place for the secondary air cleaner and the crankcase vent is just a hose connection of the rear one and is noisy.
As the bike is now it only takes unplugging the spark plugs and four bolts to remove the covers to check the valve clearances.
I have attached a picture of how it looks with no added trim.
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@CSRoad, so disassembly easy, reassembling is a bitch. I totally get why you said whole lot of paper towels. I had so much anxiety trying not to drop the retainer keepers. I did take 10min to unassembled but about an hour to get the keepers in place. Camshaft was a breeze so one side done. I felt bad for my son because I was yelling at him to “hold stead” like a pirate to get those keepers in. Saved the front for tomorrow, do you the torque specs by chance?
![Automotive tire Motor vehicle Vehicle Automotive design Automotive exterior]()
Rear is complete, as you can peep and you can see the dual springs vs single springs from stock.
The VLX600 were a tad huskier compared to the VT750DC.
![Hand Hood Automotive tire Motor vehicle Tire]()
Used two equal sized height sockets as spacers then bolted down a 10mm wrench, add zip ties to prevent movement, then put some tape to keep it from sliding. Used 21mm wrench to leverage it down, badabing bada boom keepers are free.
Rear is complete, as you can peep and you can see the dual springs vs single springs from stock.
The VLX600 were a tad huskier compared to the VT750DC.
Used two equal sized height sockets as spacers then bolted down a 10mm wrench, add zip ties to prevent movement, then put some tape to keep it from sliding. Used 21mm wrench to leverage it down, badabing bada boom keepers are free.
Just scored NT650 Carbs, I currently rebuilt my factory pair which are 34mm, do you think I stand to gain anything from the NT650 carbs vs the factory, What’s your take?
I think imma set it as if it was an NT650 with velocity stacks and jetting with and open exhaust as per the carbjet calculator.
The diaphragm caps are larger than the 750 as I was hopping to keep the finned covers from TJB but now I can’t.
I looked at frame I may need to run the Velocity stacks for sure unless I wanna pack the in the foam from a uni-filer.
So scored NT650 carbs for $70 shipped, and they are gonna be in a Pinesol dip tonight, sadly choke was not present which is okay. I’ll be doing a full rebuild.
From the looks of it, it was pretty clean on the inside but outside was pretty dirty.
I did the "4 degree" mod when I replaced the clutch soon after I got the bike (2014), but backed it off when I switched to the Ignitech box (2015}.
The "4 degree" mod simply bumps the initial timing which then effectively shifts the whole advance curve contained in the stock ICM.
If you look at the Dyna3000 advance curves on the chart and imagine the stock curve moved up by 4 degrees + or - then you see the appeal of the cheap fix and its limitations.
![Colorfulness Rectangle Slope Plot Font]()
Colorized chart thanks to Drive_Bye. Drive_Bye's Lead Sled
The "4 degree" mod simply bumps the initial timing which then effectively shifts the whole advance curve contained in the stock ICM.
If you look at the Dyna3000 advance curves on the chart and imagine the stock curve moved up by 4 degrees + or - then you see the appeal of the cheap fix and its limitations.
Colorized chart thanks to Drive_Bye. Drive_Bye's Lead Sled
Love it!
just put it back together, still need bowl gaskets, and I grabbed some Velocity stacks from eBay $11 a piece, I measured the inlet outer diameter at 54.75mm. Hopefully they fit, far cheaper than TJB at $100 plus tax and shipping.
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