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Discussion Starter · #1 ·
Ive been on here a long time lurking and finally had a question worth asking some experts. I have been building this T140 for about 2 years in an effort to run at Maxton(when I started, now Wilmington, Oh) and then one day at the salt flats. I hope to go in June of this year to Wilmington Oh, if all works out well.
My first question is carb choice? I have an original triumph that has Amals on it, and I would never change that. I understand why they are what is suppose to be there....but I feel they are limited in their tuneability, and their simplicity and restriction makes them a bad choice for my project. I called Sudco about different Mikuni's and had a bad experience with them. I was told that nothing bigger than 34mm would run on a triumph. If I wanted somthing bigger, order whatever i like, but it will not work well. I then talked to Kevin Gilham through Email from Lectron Carbs and he was awsome. Says he has a ton of dyno test and can prove his carbs at top end. Said dual 40mm carbs should work well, also recomended by John Melniczuk, who built the engine, and Lectron can set em up.
Anyone ever run lectrons on a triumph, or somthing similar?
I am open to self depercation and questioning of my parts and execution , so dont be afraid. Ive wanted to do this for years, so, if you have insite, let me know. Ive done alot of the machinne work on my own, But i am not one to steal credit. John Melniczuk from J&m Enterprise did motor design and assembly and Kyle Morley from Execution did the paint work. Couldn't more highly recommend either one.
I may work backwords at some point, i have about 200 pictures of the build, but here's the bike so far.
 

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Discussion Starter · #3 ·
I will try to get some up a little later too. The Black photo is after I floated a Valve. I was doing about 115..., not really, i overreved it at about 40mph. I pulled the original 650 motor after that and had a 73 5 speed 750 built.
I am inspired how builders manage to post Glamor Shots quality photos of every part of the build. I much appriciate it, but am toooo slow to pull it off. Excuse the por quality. Thanks.
 

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Holy bad ass motor Batman!!!!!! You have some cash in that engine. Looks great too. How about the selection of parts you used and where they are from.?. M.A.P.? Maybe? Beautiful paint. I'd be afraid to ride a bike like that on the salt with tins like that.
 

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Discussion Starter · #6 ·
Thanks for the positive Imput. I started wit a goal of 6000$ into the motor... It went right on past. I haven't run it yet, have ^no idea if it will pay off.
The billet crank and cylinder and pistons are M.A.P. Along with the wide belt drive. Pretty cool it eliminated the stator and magnet without running that gigantic spacer. Alot of the smaller Pices too. The cams are megacycle. The breather, narrowed timing gears, maching for the 21 took sprocket, and all new 5speed is J&M Enterprise here in nj. I cut down the sprockets to 2/8ths for 520 chain.
 

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I just read your first post,the rule of the thumb is to run carbs that are 85% of the diameter of you intake valves. Wich is great if you run slide carbs,a little bigger if you run butterfly carbs. So what is te size of your intake valves and intake ports?
 

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Discussion Starter · #9 ·
I think think the valves are 1 5/8. I have all the head paperwork in the garage. I will look into that. I really enjoy the math of it all.
 

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I can't speak for Ohio but at Bonneville the bigger the better. Bonneville is at altitude and the density altitude can be as high as 7500 ft. But usually much lower. I run a 540cc Weslake single and use a 45mm round slide Mikuni. I had run a 38mm flat slide Kehin but the 45mm Mikuni works way better. Go as big as your engine will tolerate. Remember its just plain flat out.
 

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People will say this carb works great or that carb. Which, no doubt, is true in the everyday world where you are opening and closing the throttle. Where the carb is on part throttle or held on half throttle or cruising at 70. Like I said Bonneville is flat out. You don't have to be concerned about the primaries other than for starting. Main jet is the only concern. Gas in. Burn it. Gas out. The bigger the hole the more you get in. The bigger the bang. The faster you go.

 

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Not all amals are unsuitable ,the Mk2 amals were very popular in pro stock motorcycle racing ,very tuneable (they have a greater selection parts for tuning than the Mk 1's),and run great at full throttle.
But back to your bike (which looks amazing BTW)If I understand correctly the guy who built your engine also recommends the lectrons ,then thats what you should try, as he understands the package he put together.My guess is once you understand the package then you can have fun and play around .
I do have a pair of Lectrons ,and the bloke who ran them on his 750 bonnie street bike (before I got the bike and sold off the rest of the engine an kept the carbs) was always impressed by how smooth and crisp the bike was.
The smooth bore of a flat slide carb like an lectron makes for excellent fuel atomisation due to minimum turbulence.
cheers R
 

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The one thing that catches a lot of people out at Bonneville is fuel flow. The problem may not arise at Ohio a its only a mile but running flat out for three miles tends to drain the bowl faster than the gas can get in. Whatever carb you use check to make sure it will flow enough to run wide open for three miles.
 

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Discussion Starter · #15 ·
Any info helps. The engine builder showed ^me his Mikunies that ^he used a dremel to cut a slot just above the needle seat to help flow. Thought that was slick.
 

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Any info helps. The engine builder showed ^me his Mikunies that ^he used a dremel to cut a slot just above the needle seat to help flow. Thought that was slick.
Sounds like you have clever engine builder!!
 

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Hoof, does the racing design head of the Weslake allow the flow of a 45mm and if it was something more ordinary, such as an ES-2 motor, it couldn't handle such a big carb?
 

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Ducbsa. Yes it does. On the intake manifold the original size is too small. I welded a larger piece of aluminum tube to match the 45mm carb. Then hogged out the inside to match. Some porting on the head to match and away you go. Speedway bikes in England are restricted to 34mm carbs. But they aren't here from what I know. I have hear of some of the bikes running 50mm carbs. I'm curious to try that but finances at the moment don't run to a bigger carb. Here's a very short video of how well it works. Bonneville this year. Mile average was 129.744. Top speed was 134. On gas. No complaints from me. I love the sound of singles. Crank up the volume.


I don't think an ES2 could handle such a large carb. The Weslake is a four valve head and a shorter stroke (85mm vs,. 100mm). I was showing 8000 rpm which an ES2 would never get to and live. As the Brits would say. Plonker vs. racer. I suppose if you are dertermined enough you could do it. There was an Aussie years ago that built an ES2 for vintage racing and it was a flyer. But with all the mods he did it would have been easier to buy a Weslake or Jawa. Pig headedness goes a long ways.
 

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Bike looks great! Kyle does immaculate paint work. Is that the same paint Kyle used on his old Honda? Since you already have the Amal's, throw em on for when you get the motor fired up. Tune them as best as possible and take a ride down to see John. He has been around for a long time and knows what he is doing. Whether you run Lectrons or Amals remember John built and designed that badass 750 so he will be able to help get that thing running like a bat out of hell! I would trust his judgement.
 
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