I'm going to use used Triumph parts and other Ebay sourced cross referenced parts to keep the cost down and a programmable ignition module with a Wide Band Oxygen sensor for jetting feedback and data logging. Keeping the carbs, no USD forks or GPS speedo's.

 

My Inspiration bike

You realize that....

1) your inspirtation bike has so much frame structure cut out of it that it's probably a pretty terrible riding motorcycle, and...
2) that if you wanted something that looks like that you could have just bought a 1998 Thunderbird sport and added clip-ons, an exhaust and a corbin gunfighter saddle:

 

View attachment 31938

Those goofy flyscreen/headlight surrounds always make me think of Flame from Animaniacs – even more so in this color.

 

Very true, I could have just bought a Thunderbird sport, but what's the fun in that.

The Tbird only has 80hp and the trident has 98 with better cams, higher compression, better rake and track, higher rev limit, tubeless wheels. The Trident was 600 bucks a Tbird Sport are 4k and up, that's a lot of go fast parts I can buy and track tires. In the end I wanted a project to tinker with, try new ideas such as the coil on plug ignition, wide band oxygen sensor and some other stuff with out chopping up a perfectly good old man bike.

 

Very true, I could have just bought a Thunderbird sport, but what's the fun in that.

Riding it and then upgrading to 98 hp specs in the winter.

The Tbird only has 80hp and the trident has 98 with better cams, higher compression, better rake and track, higher rev limit, tubeless wheels. The Trident was 600 bucks a Tbird Sport are 4k and up, that's a lot of go fast parts I can buy and track tires. In the end I wanted a project to tinker with, try new ideas such as the coil on plug ignition, wide band oxygen sensor and some other stuff with out chopping up a perfectly good old man bike.

ok, let's see what you can do.

 

Very Funny, never been a fan of those either.

 

Does not compute :/ are you building a street bike to racing spec or a track bike with pollution control devices?

 

Street bike with some track usage in mind. Im guessing the oxygen sensor is related to the pollution control question.
A wideband oxygen sensor is a great tool to use when changing fueling on any internal combustion engine. With the info it provides you can tailor your jet selection and the new controllers are so small I will be hiding it out of sight and use the on board blue tooth transmitter to view the data on my cell phone, when stopped of course.

 

Just found your other thread "I have always had fuel injected projects and this is my first carbureted project and I chose to do this to myself, I will have to remind myself later." Yep, das is for sure!
Sounds like you are hoping to apply modern tuning techniques to obsolete carburetor technology to me :/ Best luck with the endeavour.

What's the idea of the slightly lighter X-ring chain, are you wanting to lighten the final drive by a whole 2 pounds at the cost of longevity, do you need all new sprockets and chain and plan to save a few bucks, or are you trying to make clearance for a fatter tire?

 

I hear you on the tuning, its a challenge but I admit not typical. I will see how the info comes out. From what I have read on the CVK36 carb they are easier to tune that say and FCR flat slide. It will all be a learning experience for sure.

Im doing the 520 just because, thought I would try it out. The bike needs a chain and sprockets so I was curious and found some Honda parts that will work. The bike is for seasonal use, the diminished longevity of the chain is not a high priority, the challenge of making it work sounded cool. Although race bikes do change their chains very frequently the chain is able to hold up to the 100 or so HP I plan on producing plus no standing starts for me either. It was more or less and Why not.

 

I can't fault that, personally I am thinking of replacing my sealed chain with a regular roller chain aka racing chain aka let the sucker fling grease and I'll just clean the wheel more often.

You do realize however; the difference between FI and CV is that with FI you turn the throttle and it's all happening right now, with CV you twist the throttle and eventually it happens
CV carburetors suck. ... literally! To my recollection nobody Ever put vacuum carburetors on a motor for track performance considerations, they came about purely as a need to comply with emission standards of the day and that day is gone, imho you are going to be disappointed with the CV carburetor technology and a toolbox full of little brass jets that you have to swap out depending on the climate and elevation changes. ymmv.

btw Utah is a very place, love your Moab !

 

Utah has some great riding when its not snowing.

From the carb issue, I know it is a new experience for me, we shall see. I keeping the CVK36 carbs only because they came with the bike and from what I have heard they are less problematic when riding in town, is it true the FCR are either on or off?

 

Utah has some great riding when its not snowing. ...

That's why I love it so much it's just like home but without the trees, and because it's a motorcycle friendly place.

 

The '98 should have come with CVK36s.

I have CVK36s on my '98 TBS and FCR39s on my '99 Legend. The difference is significant.

If you're buying a new set of carbs, pick the FCRs.

 

How are the FCR's in mid to light throttle, like in traffic? How are they to tune?

 

Just thought of something worth mentioning on that point; Trials bikes are used mostly for slower speed riding and rarely need to achieve maximum capable speed, manufacturers typically fit them with smaller bore carburetors compared to their motocross counterparts. The reason is because they can achieve better low speed fuel/air control with the smaller carburetor. If you want to avoid problems at mid to light throttle operation and don't mind giving up some land speed record performance, you would probably be advised against going too over-sized on the carburetors.

 

Keihin FCR is a completely different beast compared to Any Constant Velocity carburetor.

Are they(FCR) either on or off :/ nothing at all like a Lake injector. Does a CV carburetor respond to your throttle, nope, it responds to the vacuum that hopefully happens when you call for more throttle. CV carburetors can have as many as 5 fueling circuits, pretty sure FCR has 2, they can't help but be easier to tune in view of the modifications you have planned. CV carburetors came to find their way on motorcycles because manufacturers were compelled to make them run as lean as possible under all operating parameters and they do just that. Everything you are doing to your engine in the way of modifying the intake and exhaust is contrary to that criteria.

But don't let me stop you, you too can experience the joy of tuning a bank of lean mean CV motorcycle carburetors.

 

Oh btw, a bank of FCR carburetors is probably going to put you slightly over budget but at least you only need 3 of em.

 

Very Interesting.

 

lol have you ever seen a Lake injector:

<- made with 100% real tree wood.

You don't want them.

 

Both sets of carbs are smooth throughout full operation as long as your throttle handle is smooth. Neither has any issue in traffic.

You can order the FCRs from Sudco already set up. They're listed for 1995 Speed Triple. I just had to tweak the air/fuel mix. Jetting was fine.

If cost is an issue, it'll be easier to find a second hand set of CVK36s.

 

one of the issues tuning (edit - i should have said "data logging and making sense of said data log with") cv carbs is that there's no measurable relationship between throttle opening and slide position. do the cvk have a tps? that will help to some extent. i used manifold vacuum when i was logging my monster 38 bdst carbs, but even that is just guessing. in terms of needle you make a change and relog and see what happened to get a feel for what did what. collect enough data though and it will help to compile a knowledge base.

fcr have everything the cv carbs have but plus one - pilot jet, slow air screw, mixture screw, needle, needle jet and main jet. the slow air screw overlaps with the mixture screw and i don't really get why it's there, or made adjustable anyway. seems like an added complication to me.

 

fcr have everything the cv carbs have but plus one - pilot jet, slow air screw, mixture screw, needle, needle jet and main jet. the slow air screw overlaps with the mixture screw and i don't really get why it's there, or made adjustable anyway. seems like an added complication to me.

FCRs also have an accelerator pump.

 

CV's are for those too numb handed to use FCR's

Quite often a slow air screw is used to provide better bottom end pick up and weakens off the mixture at WOT if it bleeds into the emulsion tube.

As trialsrider said: small carbs for low end torque at the expense of outright powah and big carbs sacrifice bottom end torque and flexibility for maximum airflow at high rippums.

Either way, unless you are doing serious tuning work on the engine, the stock carbs are right for the bike and would just benefit careful setup and tweaking in to the lump and pipe.

 

If it looks anything like this

it shouldn't need a lot of hacking. Not sure how a TBird or Legend tank would fit in the scheme without custom everything else as far as bodywork...

 

Since all the first gen Hinckley Triumphs shared frame/engine architecture, should create few, if any issues. Hacking off the rear subframe shouldn't do anything but remove some weight. Those frames were very robust.

Good project. But as has been mentioned, you coulda bought a Tbird sport...

 

Pretty sure it looks more like this:

but rustier.

 

I have been looking into the FCR's a bit more, sounds enticing. My goal is to have the bike assembled with the stock 885 engine for 2017 riding season then go through it with a finer tooth comb in the winter of 2017 and refine things and go through the engine. I will probably do the FCR at this time with a jump in displacement and head/port/valve work.

The Trident pictures is the same color as the one I have.

The idea of getting a Tbird did cross my mind but I wanted tubeless tires, better cams, 6 speed, Keihin Carbs, 3 to 2 header, Improved rake and trail for performance riding, and a few other differences. The Trident was 600 bucks, a T bird in similar state was over a grand in my area.

For now Im getting some parts while I am waiting for the tank. I have the seat pan already and the two together will determine the sub frame location.

 

Where it sits today.

 

View attachment 31969

Where it sits today.

Keep going......

The big challenge is that the rear sub frame is welded to the frame, and has the footpegs attached to it.......and the whole thing looks butt ugly

I'm constructing a sub frame in aluminium, using the existing subframe as a jig which I will cut off when I'm finished, and have bought 675R rear sets to bolt to the side plates of the frame. It's getting more complex as we go.....

 

Stunning.

 

I have the bearing codes for the rear linkage if you decide to rebuild yours. Pretty much all the bits for 'em are available from Triumph still but you can shave off a few dollars by buying quality bearings from cheaper sources. The guy who I'm doing the Trophy for is looking to cafe racer either the Trophy or his Sprint so I'll keep an eye out here. I have quite a bit of tech info and cross reference stuff on Hinckley Trumpets so let me know if you get stuck with owt.