Bonneville America Forums Forums Technical Forums Performance Mods FCR 39mm

http://www.british-customs.com/store/tri...arburetors.html

comments please? wondering how these would compare to the mukunis not only in performance but in reliability

Frank

i belive they are to big for a stock motor i would not go that big only if i had a big bb kit..

i have ran my mikuni's for all most a year now and i really like them.. i will be pull my head soon and taking it over for some work and will also get bigger vales put in also and see what gain's i get when i get it dyno and yes i did get it dyno last year with just the mikuni's on a stock motor and i did have good HP AND TORQUE but a few day later i found crap in the fuel line so i really can't use that dyno..

BIKER

I was down at Pure Triumph last week and I saw a set of these installed on an 05 Bonnie that also had a BB just done to it. I know the manifolds had to be changed. I did not ask about the head ports. I will talk to them tomorrow and get more info.

The owner wanted the shop to do the break-in and pick it up 'ready to go'. Pathetic.

Like biker says, you should have the big bore for these carbs because 39mm is friggin BIG! Overkill for a stock motor. IMO and looking at the price difference between Mikuni and the CR's, I'd opt for the Mikunis.

I have a pair of Mikuni HSRs on my bonnie along with 904 kit, conservative port work, stock valves, etc....very happy with the carbs.

Theres a guy on rat.net that just got a pair of them, he hasnt had his motor bored out yet...and plans to try them with the stock bore.

If your gonna spend that kinda jack...get the mikuni's.

i was just wondering because i have heard that the khein carbs are a better built more reliable carb (less o rings and whatnot) and i know we have a few uys who are really into this stuff on here and i wanted to here the other opinions

Frank

I completely tore down my mikuni's for polishing, it doesnt get any simpler than the mikuni.

I added these carbs last to the list of my performance mods, and gained 8hp on the dyno...the same dyno and operator that tested it prior to the carbs.

ok, sounds good to me then, maybe it is the older carbs but the mechanic at my dealer (former racer) hates mikunis for some reason, said they were nothing but trouble on the older triumphs, but i have heard no bad things about those carbs in bb bikes. mileage change much?

Frank

Yea the mileage dropped off, but it's going to when you go from a 36mm cvk to a 42mm flatslide.

I go a little over 100 miles till reserve, depending on how hard I'm on it.

The mechanic at my dealer is a former racer also, and now wrenches part time for a rider, he loves the mikunis.

C'mon Pat start pumpin' out those carbs..

what were you hp and tq numbers? also how much difference in mileage?

Frank

After the carbs were installed...
83 hp
61 lbft torque

As a side note the accel pumps were enabled at that time, they have since been disabled and properly tuned...numbers now may vary.

I'd only be guessing about mileage, it's certainly less. As I said above I go about 100 miles more or less till I hit reserve.

you do the math....

oh i was asking biker because he has a different type of mikunis, i believe 36mm and they are on a stock bore bike

Frank

umm.....


...oops

well frank i put the number's out there but people need to know... i found crap in my fuel lines in fact it so big it caused my float to stick open and that is how i found that i had crap in my fuel lines..

64HP 54 TORQUE...

and i hit my reserve right about 95 miles...

now i also keep them on the rich side and did not have them dialed in all the way...i got them close and rode.. it was time to ride and i did not want to mess with them.. but over all i found these carbs to great.. and did what i wanted from them.. i belive once i get my head work done.. and i will also be getting the Nology ProFire High Performance Ignition Coils
that it will make this set up better


BIKER

I am running 36MM mikuni flat slide...........


BIKER

So SCC has a big bore and bigger carbs as opposed to Ed's standard 790 and 36mm carbs, and there's a TWENTY HP difference? Yikes! So Ed you think cause of the crud in the fuel line it could have been better?

The reason I am asking is I would love to find a carb that would work well on the 790's, but also work well if there was a cam upgrade in my future, and also work well if a big bore were in my future.

I have some questions also...

Sitting here thinking about what I want to ask before I even begin typing, I think I should say that theres no intention of coming off like a smartass. There's also no intention of demeaning your ability's nor reasoning for doing what you've done...sometime's its hard to tell how someone is tryin to come off when reading forums and such.

Just dont want to be misunderstood...


But I gotta know....why you chose 36mm mikuni's.

Your end result doesnt appear to be far from my setup when I had my stock cvk carbs, free flowing exhaust, airbox removal etc...

Just wondering what you've found the benefit to be using the mikuni's over the stock cvk's is all.

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Ed you think cause of the crud in the fuel line it could have been better

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yes i do ... i just made new fuel lines and I should haved blowed them out.. but see what happen's when you try to do thing fast and also i was running one of the cheap after market exhaust..that i know also made a diffrance..and also like i said the jet's were close but not dead on yet.. and with all that going on it still pulled like mother ..

BIKER

well thats easy... there less then half the cost of the cvk
they respond faster and you can get parts for them at any bike shop..


so SCCTRIM were do you live your back ground is very blank
you don't give much info about you self or what kind of bike you ride?????

ED ....BIKER

How rude of me

I'm from PA...Hanover. I ride a '06 bonnie black, bought her in May of last year. 1st bike I have had in 18 years, didnt realize how much I missed riding till I mounted her.

Several mods, both asthetic and performance wise. More than I care to list actually, if I read off the list I'll be faced with how much I've spent modding her. Still plan on taking mod's further. Changing out the front forks, better braking, perhaps yet another performance mod or 2...would like to add about 10 more hp at the rear wheel.



Heres a pic



Ok...back on topic now

very nice to chat whit you..and thats a very sharp bike you have there

Ed

Thanks man...maybe I'll seeya at mid-ohio, or the come home rally...or another event somewhere.

Sheldon,
Welcome to our site, I have read several of your posts over in the 2001 modified forum as well.
In hanover, PA you are about 260 miles south of me. Just follow 15 north till you get here. Stop on up and visit us in september at our NorEast rally. Usually the third of forth weekend of September. probably change it to the 15th this year as RAT has decided to have theirs in Gettysburg on the same weekend I originally planned for.
I also have a set of the 36mm Mikunis that Ed (biker) has. In fact he lives about 7 miles away and we hook up a lot. I just need to finish a new cable to install mine, but it's winter now and I will get it done in the next month or so...really guys, really!

Promises promises.
Stop watching the Godfather and get to it!

Thanks Pat...maybe I can make the trip this year. Appreciate the invite, got any plan's to attend the comehome rally here in PA?

Hope to see some of you there.

I have gone to the TCH rally a couple of times. Last year Matt and I left home and got 100+ miles before the torrential downpour finally made Matt's Speedy lose the spark. had to call the wife to come rescue him with the truck. That one was called the "Triumph Go Home" rally.

Quote:

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Are the Dinqua carb kits really going to happen?

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Yes they are. They will be a less expensive option than the others out there. And of course improved response and HP is first priority.

OK I haven't been on here in awhile and obviously I've missed alot, but what are these carb kits that I'm now reading about?

Jim,
Ed (biker) and I have been playing with some different carbs. He has a pair of the 36mm Mikuni flatsides on his bike right now. They are relatively inexpensive (about $140 each), but require making a bracket ($15), new K&N air filters ($60 a pair - they are NOT the same as the freak ones), new throttle cable ($30) and jetting once installed. They are a bit more complicated to setup, but I think the work will be worth it once it's all done. Also the options for jetting, needles and such is almost unlimited - a very nice reason to use them. I also have a set of them in my garage with the new cable, bracket and filters, I just need to actually take the time to put them on the bike and dial them in. But with the nice weather we've had, i didn't want to make the bike unridable in case I got a day to go out again, like last week. Now that it's snowing and icy, I'll have to dig out the ole "round tuit" you sent to me.
We also played with some of the new Amal carbs from Norman Hyde, they pretty much sucked the big one. They leaked gas all the time and we could not get them to stop spewing no matter what we did, and we did everything - gaskets, hoses, o-rings etc etc. We put them on Matt's big bore bike and it ran like a beast when it did run, but it would quickly flood and die and leave the bike covered with gas everytime we rode the thing. They went back to Norman Hyde.
So, now we're playing with the Mikunis. we got them from Pro-Flo in PA. Once we get them figured out for a 780cc like Ed's, and a 904cc like mine, we will probably offer them for sale or give destructions for the brave to make their own up. I have been asked by some vendors to sell them through them, but I'm still debating if I really want to get into carb selling business. Might just be easier to splain it to everyone and let them have at it themselves. But, for enough money I'll eat dog poop.

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But, for enough money I'll eat dog poop.

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It's true. I've seen it.

I'm definitely looking forward to your results Pat. I'd love to make my own bracket, and I could probably make my own cable too if I learned how. So varying levels of pre-assembled-ness-ability would be schweeet.

>It's true. I've seen it.

Ok, I've got more questions. These are for Pat, I'll repeat what I said earlier...

Actually I'll condense it...don't take this the wrong way

Are you certain you got everything you could out of the 42mm mikuni's? I recall reading a post from you in the original thread I started about carbs and stuf that you felt that the bike was over carb'd...and they had to be jetted so far down it wasnt worth it.

I also seem to recall a post of yours that said you got minimal gain's oon paper when u dyno'd the bike.


I had to ask this as I've got the HSR's and, aside from cold start idling..( which it does but doesnt like to )...the carbs have been great. +8 hp on the dyno was my end result, and that was with the accel pumps enabled.

Understand I'm not questioning your abilitys man, just your decision to step away from them.

i'll try to explain these carb's better and why i went with them .....

in the past when riding with pat with his BB kit man his bike was fast and i mean fast from a dead stop to 5 gear he could easy get 150 feet a head of me np at all !!!!! and i could not keep up with him ..

SO I LOOKED FOR A CARB THAT I MITE BE ABLE TO MAKE WORK ON OUR BIKES AND GET GOOD GAIN'S SO I WENT WITH A FLAT TRACK CARB.. 36MM MIKUIN FLAT SLIDES...

this past year with the mikuni's i was able to keep up in fact from a stop to 5 gear i was only a few feet behind not a 150... these thing pull and respond much fast then our stock one's... was he still faster then me hell yes...

so for under $500.00 i got a great set of carb's that have a wide range of adjustment..

now for them hrs 42 they will run you about $1500.00 but its a very nice set up....

but once i get my head work done i belive it will make this carb set up run much better..

BIKER

Right on...I would assume when he get's those carbs on his bike that few feet will grow a bit...representing the difference between the 904 kit and the stock bore. I just felt like I got alot better end result outta the 42's than Pat did...maybe I didnt.

Don't know if you guy's are coming to the come home rally or not, but I'm gonna try to make it to your's if work permit's me to be away.

Thanks Ed.

Pat, I just got $1500 from selling my XS650 hardtail project, and it was going to go straight to bonnevilleperformance for a 41mm kit, I sure would like to save about 1/2 that amount of money...

Thanks for your efforts. They are appreciated.

If you don't end up making/selling kits I would certianly like plans/info to make my own. Actually I would prefer to make my own, I like to make things.

Let me try to answer all the questions at once:

Sheldon,
No offense taken, I know exactly what you mean.
I did have Bill's HSR42s on the bike for about 4 months. yes, they are an outstanding product and superior to the 36mm flat sides due to the extra braces and stuff Bill has designed, however...I do not want to say anything bad about Bill or any or his products - but the 42s, when they first came out I got them, were flooding the cylinders and causing backfiring on WOT. I disabled the accel. pumps, jetted as low as jets were presently available, leanest needle (97s I believe they were) ans still had way too much gas. I tried different pipes per Bills direction but still too much gas. After many tries Bill told me to send them back for a refund which I did. I also knew two other guys that bought them the same time I got mine and to this day they are still too rich, even after the big bore. But I know hear there are new smaller jets available to jet them down even more, right into the correct range I am told.
Now, the newer 36mm carbs are a different animal as well. They do not have the accellerator pumps. They also have several hundred variations o main jets, needles, and pilot lets easily available at every bike shop I have spoken with.
But the big reason was price. I am one cheap, errr, thrifty guy. The 36s each cost me about $135 a few months ago (price has risen a little since then). They have a two into one throttle system where Bills have a custom bracket with dual throttle cables, similar to the stock mechanism, but way different then the 36ers. The 36s are a bit harder to disassemble and jet compared to the 42s as well. But I figure for the price, I can take a risk with them.
I just felt that the $1600 I paid for the polished 42s and having to jet them way down was a little overkill and not the best HP per dollar return, as compared to say the Wiseco kit which is the best money spent so far.

I just finished hanging out with the yute, Matt, and we discussed getting my act together and finishing the carbs this next week. So I will finally try to get the cable cut to the right length and shove the suckers on. I just need to do a little research and talk with Ed some more to try and get the jetting close on the initial install.

As for anyone that is thinking of buying bill's carbs, i say go for them if you have a big bore and the cash. They really are a sweet product and i would use them before I would consider teh FCR39s for sure. Besides, you can buy a set of three FCR39s for the Triumph triples for about $600 from Sudco, a third of what BC is sellinf them for. Make up your own brace and away you go, stalling at the stoplights when you gas them though. I have heard this is the biggest drawback to the FCRs. They are also way too rich in the idle area and take some getting used to.

edit: Oh, and Ed is still a little dot in my mirrors...

Did'nt occur to me that there may have been difference's in the availability of jets/needles and such between the time you had the carbs and now. No denying almost everything for our bikes is alotta money. I guess it's like everything else...

Thanks Pat...look forward to meeting you later this year.