Howdo! Another question Ref:FCR's Using a bank of FCR's is it possible to run without a fuel pump?? Or is this only for the splits? I believe a few people are running an external pump - any pics, issues over standard pump? Thanks for any advice/will also do the search trawl. Cheers Pablo
The carbed SSs with the Mikunis run at something around 3 - 4 psi. As Steve says, you should be able to gravity feed the FCRs, but you need the fuel pipe from the tank in a continuous drop to the carbs, otherwise you will be 'priming' the hose every time you stop, because of airlocks. But you will probably find you need an on/off tap as many people have found the FCRs overflowing when stationary.....you can wire an electric one into the pump elecs quite easily.....There is a link on this forum somewhere to an ebay site which sells them..... If you find you need a pump, I suggest you try a Facet Solid State one (1-4psi) which you can mount on the right side of the bike where the fairing support tube is....(you need to make a little bracket).......that way it can get some air. It's pretty small, but a bit noisy (but you won't hear it above the noise from a dry clutch)....... FuelPumpsOnline do an offer on the pump.....and they do external filters as well.
Hi Pablo, I am running 41mm's on my 900. I only have the stock fuel pump. It runs great, however I did have teething problems with them flooding the crankcase. This must have been dirt in the float needle preventing it shutting. You don't need another pump, the carbs have a mechanical pump in them and I have heard u can over pressurise the Flatslides. Mine are banked. I have an additional inline filter and at the moment a manual fuel tap but bought a solenoid fuel tap from Poland on ebay. Not fitted it yet but will soon as I forget to turn it off, it's only flooded the crankcase once..... Awesome carbs though
Pab, the Keihin FCR's handle 3 bar as a guideline pressure. Your stock fuel pump won't reach this so you're safe. The only reason we ever ran a fuel pump was really to guarantee the return loop if I remember correctly. The Facet SS pump is a real gem and would be an ideal replacement to that horrible in tank mallarky, it also has a power shutoff as well so if the engine isn't running it won't pump. One thing I would say is this get the things rolling road setup as out of the box and with baseline set they're not at their best. Mine were dumping most of my tank down the bores before I had this and the worst was when I got back from a ride and they were pissing fuel like a garden hose - the only reason the bike didn't catch fire was because there was far too much liquid flowing to allow ignition! Touch wood since then mine have been as good as gold. Oh and the float seats dry out and get stuck quite quickly as well, but the latter can be sorted out with a gentle but firm tap from a hammer handle against the float bowl body from the side. Adding to what DesmoQuattro said, they have an accelerator pump in them which isn't a pump per se, but it allows them to start without a choke (they don't have chokes) by squirting fuel into the bores on a shut throttle. However, this won't overflow the float bowls, that'll be down to float seat and heights. They don't have a fuel return circuit either, so your fill and return look will be Y peiced together. Why would you want to run FCR's over your current injectors out of interest?
I'm not AL, but if I can keep hold of this bike t'other side of the new year then I'm looking to do just that as I think its a way better option.
Cheers Gents, Had FCR's on my 944cc motor, however looking at a different tank which would either require no pump/external pump. It's a long term build so will probably be asking again (It's an age thing!). Cheers Pablo
Pablo, I also have a long term SS project with 944 engine! Got lots of parts but always looking for improvements. May order a facet pump. Does anyone know what part number should I get? Looking at them the pressures are quite specific. Ian
One of these would be correct IMO...... Facet Posi-Flow Electric Fuel Pump 1 5-4 00psi 60104 - special offer with straight unions ...and you have the choice of varying the kit on their website. I would also get the pump mounting bracket which you then bolt to a small bracket to you will need to make.......that way the pump can be fitted to the web in the frame where the right side fairing lower is fitted to the tube mount. It puts the pump into the airflow without affecting the rear cylinder airflow, but it is also within the correct height range for gravity priming. They also do a similar pump in this range with a check valve, but I'm not sure if the low pressure version is available. Get an electric stop valve as well......there is a link to an ebay site on this forum somewhere.........wire it into the fuel pump wiring.
8mm unions I reckon........and don't forget the filter/s... You can have one each side of the pump......One biggy on the tank side and a small one on the carb side (just in case of pump failure)... But, you must have a return flow to the tank......this is one of the reasons why FCRs overflow.
Nah.........just use a 'Y' in the fuel line after the pump, so the pressure in the fuel line is relieved. I reckon the only reason there is a pump on the SSs is to get the fuel out of the tank and maintain a supply to the carbs....the OEM 'Y' removes the pressure. I'm fairly certain if the tank was able to feed by gravity, the Mikunis wouldn't need a pump. There wasn't a pump to feed the bloody great pumper Dellortos on my Guzzi......
that was exactly it in a nutshell, it was really packaging of the tank / carb realtionship that made that pump happen, nothing more than to ensure a return feed. My fcr's are exactly like that, they have the pump and return lines going into a Y (outside of the pump) before feeding into the carbs.
Howdo Ian, Go on what have you done to the engine??? Always interested in what people have done........ Not going crazy with this motor - Hi-comps, 600ss flywheel, pulleys and FCR's. Cheers Pablo
Pump ordered, brackets 30£ so I'll make my own. Pablo my engines not going to be that special, FCRs high comp 944, so far, ca cycleworks coils and ignitech ignition too. Got to get the cylinders bored next Ian
The pump mounting kit is £5.53 Facet Fuel Pump Mounting Kit The only issue I foresee in fitting it is that it might foul the air deflector which are on some of the full fairings, although it can be got in the space with careful fiddling and bracketry adjustments. The other way to mount it in the same area is on the tube of the frame just below the tank using a wrap around stainless steel strap.
They run on stock monster fuel pump (vacuum pump). Saying that electric one is better as then you can have return to tank when they overfill. And trust me FCR's will overfill with fuel ......... That is why I sold them as on daily running bike it became to unreliable. Pissing petrol every 2-3k miles with no prior warning, Monday back home in to garage all ok, Tuesday morning petrol on the floor, in the engine just not in tank.
touch wood mine have been good as gold. Replaced the float seats, rolling road setup and all was good. Only time it came a cropper was when I drained them and the seats didn't seat properly so I got the syptoms again, but a tap with a wooden hammer shaft on the side of the bowls sorted that out. As for tomorrow, who knows!
