Macduff

Fuel line quick disconnect arrived today so fitted it and took the old girl for a test ride . All good if a little baggy with age ( me and the bike) .

Well pissed about with it this afternoon and breather was clear (and wasn't actually tight into the tank), fuel tap was brand new genuine parts last year . So tested flow through filter (just draining into a pot ) and it was a bit slow compare to no filter so binned it and replaced it with a inline brass hose joiner (had a couple lying around ) and possibly a placebo effect but it seems to start easier . Other than letting it idle to check for leaks I've not tested it fully . Hope its sorted. May or may not fit the quick disconnect once it arrives (may leave it till the next time I have the tank off, as its been off more times than a whores drawers this week).

Well another year and another MOT. Some last minute gremlins appeared in my pre mot checks, no fekking side lights front or rear. A trace round the loom and a bit of unplugging and re-routing (it wasn't very well routed from PO's fiddling) and whoo hoo light returns. Took it for a slight detour to the MOT and it was running really sweet until it conked out (fek) . Felt like it had ran onto reserve but my tank was pretty full (and swapping to reserve didn't fix it). I had wondered if my CDI and fried due to COP conversion as it was just spinng on the starter. Called AA but after 1/2hr of waiting tried to start again and it fired reluctantly. Got it to the MOT station a bit late but they were happy to still test it (And it conked out !)This time it would start on choke so wondered if it was fuel starvation . I had fitted an inline fuel filter when last had the tank off thinking it would be good to keep crap out of the carbs and checking it appeared to be half full of air or fuel dependant on your preference which was odd as it is below the fuel tap so gravity should have filled it (maybe?) anyways leaving it alone let the filter fill up (mostly) and it started again , test quickly passed, think they were kind to me as last years (elsewhere) had raised an advisory on the rear sussie linkage for bearing play, not mentioned this time though not sure its easy to test one manned with only a sidestand.. AA man turned up (had tracked my on phone app) they agreed to follow me home incase it died again and as long as I kept the throttle action light it kept running. Going to bin the filter and replace it with a BMW spec metal quick disconnect (after my last butt clench fire with the placcy ones taking a chance with hopefully a decent version). Pic of it waiting at scene of 1st conk out. I plan on fitting my spare wheels once painted in a different with sme conti 18" sticky tyre as I hate cleaning white ones, either satin black or some retro gold are my current colour choices though the gold maybe a bit tarty.

MJsize isn't std from memory . Not sure you can get a factory pro kit for the VM29ss flatsides, never found one on my searches but you may know where to look. If you have dynojet needles I think you need to stick with DJ mains though someone with more recent experience with DJ kits than me may add more relevant info as I last fitted one in the late 80s .

They're not a cheap upgrade . I'm getting close (maybe over) to having spent more on bits than I did buying the bike.... just don't tell the missus. Just plan on riding it more this year, maybe getting the spare wheels cleaned up with bearings and tyres fitted as the current ones are getting on in years if not mileage.

If its not clear from the parts diagram its a simple rubber bung that gets pushed in the hole in the belly pan so theres a rubber flange on each side with a small metal sleeve to stop it being crushed.

Sorry not yet hopefully I'll get some miles on it once we have some better weather and I'll try to see what its like in the dark though my late night miles seem to be getting less these days.

Looks like my 2nd hand carb swap was a success. Bike starts a lot better now hot or cold , it could probably due with a fine tune and a valve clearance check but its shit loads better now than it was on the old carbs. I now have a spare set of carbs to strip /fix at my leisure initial, inspection shows the float bowls to look like they have a coating of what could be mould and the pump jet piston is stuck in one of the float bowls so I suspect the internal ccts could be in a similar manky state..

I had wondered if I’d been too stingy on choice but scanning Eblag and amazon all the placcy quick disconnects look identical bar price . There do seem to be some metal ones from about 60quid but that’s a bit much if they leak too. Guaranteed good metal ones seem to be over the ton motorworks bummer spares stock them as they might be used as oem replacments.

Well left it for a day longer than planned but gave a quick try starting today. fuel tap on for a couple of minutes then used a few squirts of the accelerator pumps (bout 10? no idea if that works on the VM29ss) full choke and whoo hooo started 2nd attempt... that's the best it started since I've had it. Fingers crossed everything else stays working long enough to enjoy the summer on it. Need to sort the fuel line as its a bit long and resting on the head don't want another fire... Got a set of 1100J wheels I need to get painted/coated and new bearings and some tyres as my current set are a bit old NoS Hi-Sports so probably best for looking at than riding...

I treat me and the slabby to a yoshi as a reason to get it sorted last year.

I think I need to change the thread title to my slabby lives dies lives dies repeat! It got harder to start at the end of autumn when temps dropped then it just plain refused. Bunged it back in the garage and made some attempts to sort with no success, issue seemed to be the carb pilot and choke ccts but played with the cop conversion incase it was failing and ended up removing the inline resistors and replaced the cop wiring with a new shorter loom. To complicate things I also swapped out the VM29ss with better set though I replaced the pilot jets and float valves in these with bits from the originals as they were new last year. One weird thing in noticed was the 2nd carb set had 20 pilots and my new ones were 32. Had another go today as weather in garage was warmer and after spending some wrist bending and scraping time refitting the carb airbox rubbers (thank fuck they were new last year) if managed to get it started (after adding some fuel to the tank!). Whoopie then fuck it dies ran out of fuel pretty quick (one std shed petrol can size (4lt) filled it with 4 ltr more but it wasn’t having it just starting on choke but dieing immediately . Got more fresh fuel in the tank brimmed but left it on charge for another go tommorrow. One minor fuck up was I replaced most of the tank to carbs fuel pipe with new , added an inline filter and a quick disconnect . The quick disconnect leaked and caught fire ! Luckily tank was on loose and I shut of fuel tap and kille the fire (small) before it got hold and burnt my garage down... so moral is don’t buy cheap fuel disconnects off fleabay. Not damage apart from a singed quick disconnect. Not sure how it ignited but seemed to have flashed off heat from head or maybe the coil and and electrical spark (fuel dripped onto it).

Quick update, in my search to solve starting issues I revisted the COP conversion and thought I'd visually check the spark at the plug. With the resistors in the cct the spark looked a bit white which I think is a bit weak, without the resistors the spark was a nice fat blue. Unfortunately I also pulled a wire from the connector to one of the coils, so nned to rewire that one before I can test further.Once I fix the wiring issue I've decided to run without the resistor pack and if the CDI fails due to driving a lower than it expects resistance I'll just replace it with an ignitech unit.

Not sure if its much use but the rear stay to the mirror ears is different on the 1100 which moves the top of the fairing forward, the 1100 Main stay for clocks and headlamps also move the fairing forward and possible up a touch. I found my 750 slabby was fitted with 1100 main and rear to mirrors fairing stays and I couldn't get the mids and belly pan to line up with the engine and lower frame mounts, swapping both out for 750 bits fixed that.

To answer the Qs my choke knob seems to do nothing to help cold starts, the rs34s would be setup for my needs from supplier. I think my carbs need some new internals at least needles an emulsion tubes as well as an ultrasonic clean .

It looks like my slabby carbs are in need of serious tlc as the idle /cold start ccts don’t appear to work as intended , it’s a pig to cold start and hot starts are on a whim and prayer. Idle mixture settings are rich to ease cold starts. So should I attempt to locate another set of vm29ss given they will probably be the same if not already rebuilt or get a set of new RS34s? My thought are fully rebuilt vms are running close cost wise to new RS carbs though I do want to keep airbox stock. Any thoughts issues ? Ps does the central throttle cable pos on RS carbs cause issues on slabbies. Will rs34s fit slabbing intake boots and airbox trumpets ? I don’t think I need bigger than 34s as engine is stock and when it is running is fast enough for my aged brain having got it up to 10k going through gears.

And it will depend on how good a starter your engine is hot or cold. If its just a bit reluctant or tempermental a small capacity battery is just going to piss you off as some point. Though you could get one of those jump starter boxes to cover off that problem.

Wonder if the brake pads are Guzzi rear calliper pads v50? Just a guess based on the pads look similar to those Harrison 6 pots billets used which I think were guzzi rear pads.

Unfortunately not yet, since the cold weather arrived starting has been a bit tricky when cold. So I tend to use it in daytime when its slightly warmer. I need to sort the carbs out (or replace them).

I think it will take a very rich mixture to make it misfire , and your settings don't sound too rich, I think lean mixtures tend to misfire more than rich with too rich just loosing power . Its not clear reading the 1st post if the problem has always been there which could indicate a carb blockage somewhere , could be a float height issue on the cylinder affected or for my money sounds like leads plugs ignition related.

You're not wrong but the real electrickery regarding what the coils do isn't found in the basics resistance/volts/amps as it's a coil about the inductance so the basic fudge of adding a resistor in is just that a fudge . I can't remember the correct formula for inductance calls but I do know we don't have access to the input variables to be able work stuff out. I used the resistor fudge as others had reported issues for the slabby cdi which is used to feeding coils of around 5ohms primary resistance. I didn't want to burn my cdi out so made that fudge. I may locate a working spare slabby cdi and unplug my resistors to see what happens. Ps even with the fudge resistor in series my bike ran better as it filled in a mid range part throttle flat spot that think was due to lean mixture that the stock aged coli's and leads struggled to ignite.

Just a side note for Slabby CDi (not slingshot) you need to consider adding suitable resistors in series with the coil pairs to get the primary resistance up to a number that won’t cause issues for the slabby CDi. I used 2.2ohm 50watt resistors in my slabby CoP loom (posted in a thread in oil cooled earlier this year).

It seems that as the air temp drops my slabby gets harder to start and this morning it just wasnt having any of it. Pulling the choke out just makes it worse. So given that seems to be fekked I richened the idle mixture screws to about 2turns out (2out on the outer carbs and somewhere about that on the inners ). And success it starts though the rich mixture now makes getting a decent idle a problem with revs rising and falling by a few hundred revs. So if I win the lottery over Chrimbo do any of the mikuni RS carbs fit the stock airbox trumpet rubbers? I was thinking the RS34 carbs given its a stock 750 , or I could pull the VMs to see if the choke cct can be unfucked, shame as all the other ccts on the carbs seem to be working great.

Of all my bikes I've had I'd say the slabby forks I have cope with the rippled local tarmac better than any bar the WP forked KTMs and they were meant to cope with the rough. This could be that most modern sports bike forks are too stiffly sprung to give a good feel over such roads

Cheers for that , very useful.