Separate names with a comma.
Discussion in 'Some Assembly Required' started by DRjoe, Feb 4, 2009.
Bring back the thread it has been so awesome until as of late. Bump!!
drjoe, i saw this pic posted over at the drriders forum, and i thought of you...
ya, it is not a dr650, but...
Ok seen as you asked so nicely I will recomence the build shortly.
Cool pic doug an that "old tech air cooled twin is a mediocore chassis" that should be able to slaughter a few katooms.
Is it true
Drjoe heard saying i need more power this dr is gutless
yet it nailed a modern fuel injected bike
Reckon it looks likes an old KTM 2 stroke chassis, Husky swingarm (I have one in the shed), WR Yammy forks (I have some of them too)?
But I could be way wrong . . .
Bills Old KTM
I was thinking what ever frame it was it looked to have been modified near the shock mount and carbs.
It's given me an idea on how to make more room for stuff
I'm not sure about that mate, I don't remember nailing any modern bikes, did pritch nick my bike and go for a rude whilst I was having lunch?
Its sure is a nice looking frame, lightweight and all
Its OldDogs bike he is lovingly restoring
I'm looking to fit a pair of 37mm fcr-mx carbs on the 500 and I was hoping to just use one set of throttle cables with a solid link between the carbs like the original carbs use.
If I cant do that i'll fit the lighter springs to the carbs and use dual cables.
Anyone ever seen fcr-mx carbs set up with a solid link between them?
I know the 1st gen fcrs and downdraft fcrs can be set up like that but I have never seen the mx version paired up
The other option is to fit a set of mikuni flat slides.
Never seen one like that, but if your FCR has the open/close dual-cable setup like mine, you could run a short cable from the "close" side of the first carb to the "open" side of the second one. That's sort of like the early BMW oil head cable setup. Seems a bit easier than dealing with two independent cables adjustment-wise, just back out the second cable until it's barely slack when the first carb is idling.
If this is what you were planning to do anyway, don't mind me. Carry on.
I thought of that but reckoned it would be a nightmare to keep the carb balanced
I guess there's a reason BMW went to a different setup on later models. It can be a slight compromise sometimes where you get a cross-over at a certain RPM. However I've never found it to be a problem on my GS. The balancing procedure is very simple, easier than on later models with a more complex setup (some kind of cable routing box).
I would be a lot more concerned about getting the jetting and accelerator pump squirts in sync. I've spent enough time fiddling with one FCR that I don't envy the man who has two. It should rip once dialed in though.
Well I might go that way to start with till I get some thing better set up.
I hear what your saying about dialling in the acc pump I got fed up with pissing around with leak jets and cam profiles so I bought a adjustable leak jet.
best thing ever for a fcr carb, highly recommend fitting one.
what I'd realy love to do is fot a pair of apt smart carbs but there a tad out of my price range
not sure if you're talking about flat-slide-carbs. There has been one thing I had to learn from our German Suzuki DR Big-forum some time ago. We had a discussion about the difference of carb-operation between elder and newer versions of the DR 750 and 800. The Big is fed by a pair of coupled carbs. Originally, these aren't flat-slides! But changing to a pair of 'flatties' is a well known tuning-issue. Now comes in the subject of discussion: The latest versions of the DR 800 had 2 throttle-cables, one for opening, one for closing the carbs. Somebody had a broken shutter-cable and got home without any trouble. I thought of being wise enough to tell him he could leave it that way as long as the springs inside the carbs were good enough to close the (diaphram-controlled) slides. This led fellows to correct me: as long as we discuss diaphram-controlled slides, my opinion would be ok. But if you've put flat-slide-carbs on your bike it might be possible that they could get stuck in their slides if you just depend on the spring to close them. They might get sucked against the inlet and stay in that position. It seems, that it has to do with the kind of operation: some 'just slide', others use rollers to slide. The latter are not prone to get stuck as far as I understood. My concern is that using the first version with split cables is a recipe for desaster. This might not be accurate enough to make sure that the slides close when you want it. Hope, I was able to describe it in an understandable way. If you're unsure about this I can ask a friend from our forum who's very good in technical knowledge and also very good at explaining it to me. I think, I'm good enough in translating this into English.
Kind regards, Bambi
Hi bambi thanks for the info.
The fcrs have rollers on the slides. Some models don't even have closing cables.
If I did use a cross over cable between the carbs I would still use a closing cable.
Hey Joe, (cool, isn't it?)
that seems to be ok as far as I understood my forum-fellows and your description.
I'll surely keep on following your build! Had some similiar ideas with that GS-twin for my DR Big as it suffered a major-engine break-down 8 years ago. But in Germany you're not allowed to change the kind of engine so easily. Usually, you'll loose the permission to ride that vehicle. These things are very regulated here ... so I ditched my idea. Although it creeps back into mind from time to time as I like twin-engines very much!
Kind regards, Bambi
I'm guessing you're going for twin carbs as it's too difficult to get a single carb in there?
Anyway, the older Triumphs ran a 2 into 1 cable setup...a single cable from the throttle which then went into a plastic cylinder where 2 cables came out.
I think maybe some 2 strokes used them as well...1 cable for the carby and the other for the oil pump.
I've got an old vacuum guage that I used to sit on the tank of the Guzzi 1000s with a 3 way gas tap connecting hoses to the carbies.
I'd take the bike for a run and at different speeds, would turn the tap to get a reading on either cylinder and then stop and adjust. Seemed to me to be more accurate than a stationary adjustment where there is no load. You're welcome to use it when the time comes.
Anyway, good luck. Can't wait to see how it turns out
Cheers Wayne but I have vacuum guages for balancing.
I wanted to avoid using split cables but its probably the way i'll go if I use fcr-mx carbs
If I can make a solid link between the carbs I won't need special throttle cables and I can get rid of one of the return springs which will make for a lighter throttle.
Anyone got a set of mikuni pumpers that they want to give me?
You don't have to use the 2 into 1 splitter box. You can use a dual pull throttle instead. I went this way and had custom made cables to allow for individual adjustment.