Triumphrat

tritonwow · 05-04-2008

Well, I drove the bike to work two weeks ago after I thought I had fixed the carbs overflowing; was I wrong. #1 and 4 cylinders were flooded and pouring gas through the filters as I went to leave work that night. What to do; pay the moohla to rebuild the Mikunis or go for the FCRs I had been wanting to work up. No brainer really.
Fast forward today, finally have the carbs rebuilt and on the bike, fuel lines worked out, and finished up reworking the electrics/twin throttle. I'm still shortening the cables though (forgot to bring what I needed to work to shorten them and ran into the honeydew time). I couldn't resist and hit the starter even though the throttle cable isn't hooked up. It cranked 3 times and fired with a smooth idle. It seems the slides were rattlng something fierce. Let's see if that holds true tomorrow when I get the cables hooked up.
Still have the filters as the last item to put on before I run it at length.

trypcil · 05-04-2008

Part of the charm of these carbs is that they rattle like a set of errant tappets! To some they are a signature of a bike unleashed - ! What jets and needles are you using? I also recommend a push pull throttle cable and a throttle grip from a Suzuki gsxr 96ish - and K&N pods ? !

Good luck!

Hinckley · 05-04-2008

You gotta love the rattle of the FCRs!

tritonwow · 05-06-2008

Trypcil,
The 41mm are for a 91-99 GSXR1100. I've based this off the carb spacing and what Sudco lists. Searching the GSXR forums I found recommended stock (and what I'm using; that was what was in them):

Needles-EMP Pilots-55 Mains-160 Main airs-200 Fuel-.75 turn Slow air-1.5 turns*

* I couldn't find info on fuel or slow air screw settings so I used some recommended for a Duc.

She ran quite well the nine miles home. I stayed off the freeway initially only because I was unsure and the thottle is not quite sorted. It was running hotter than usual especially at the lights but droped on the lower side of the scale when moving. Once on the freeway going 50mph (or so) 3.5krpm(? I wasn't watching closely) she bogged. I backed off, rolled on the whacked it and picked up well but I think it's not quite right. All in all I'm happy she fires up and runs because my goal was to get her home. A dyno appointment is in the works.

The main issue to work out is the throttle cable (yes, I ended up using one so I could drive home.) Then I can get a safety inspection which ran out last week. Other issues:

Carb spacing on the D12 is 88mm. The GSXR spacing is 86-92-86. I turned the inner two D12 intake rubbers just so and they matched the GSXR spacing. Eventually I want to modify fuel, vent, and rail linkages so they will be properly spaced but it's working for now.

My KNs won't fit the adapters I have so I cut out four circles from UNI fine green universal sheet, soaked them in air filter oil and zip tied them to the 30mm velocity stacks. I was looking at a ZRX1100 today (judging thottle cable lengths) and noticed his KNs look like they might fit my adapters. I'll end up sourcing a set that will fit. I am wondering if an airbox with KN would still help or not.

All the cables I have run into the frame backbone because the attaching point on the carbs are so high. I've a good cable length measured now and will hit the shops looking for same length twin cables. I used a switch housing from a TT600 which plugged right in (after I transfered two loops from the old switch. I believe the push/pull tube is from a Sprint (from a Triumph just can't remember which).

trypcil · 05-06-2008

Very cool there Triton' - though I suspect that your mains maybe a little on the rich side. My 39mm's are running 155's (150 came with') and I also changed to a different taper that offered a richer period at about 1/2 throttle. As to my pilots - cannot remember and don't remember changing them! Here's a good tuning link - www.factorypro.com/tech/carbkei.htmlif - you haven't already read it! Keep us posted about those rail, vent and fuel linkages.

tritonwow · 05-27-2008

I've been having a charging issue but really wanted to take it for a spin. I replaced the single throttle cable with R6 cables from Sudco (the local shop had them). They are still a bit long but I finally have full WOT at the carb. Unfortunately, I also have about 1/4 freeplay at the grip on idle. I'm still looking for a different setup.
Anyhow, I did a short sting down and back on the freeway. WOW! The front end gets light quick and I think I've identified just how bad my front suspension is after this ride! A horrible front end compression/rebound cycle on rapid deceleration. The freeplay in the throttle cables may be the culprit so I'll examine further when I sort it out. Also, I got a horrible stutter which felt like a rev limiter (do these bikes have 'em?) but I'm almost sure I was only at 6-7k rpm (too busy trying to figure out what it was/negotiate traffic to look at the tach). Another idea was maybe the fuel delivery isn't enough and I had float bowl starvation on heavy exceleration. Again, something to sort out when I get the cables sorted.
Normal or non spirited driving was nothing spectacular. No issues I mean.
After that it's off to the dyno. I'm real curious to see where the curve is at because (although short) it seemed I didn't have any flat spots. Of course I didn't get up to max speed either.
I most likely won't get around to respacing these for quite some time. When and if I do the job I'll capture the moment and post for all.