Help! on going cafe racer/860 project
I have put everything back and sorted out carbs,(I can strip and rebuild a phf carb with my eyes closed now).
I have checked plugs and spark ok.
I have checked timing at 35’ btdc.
I have switched plugs over to check transducers correct.
All I can get out of her is a backfire if I use a bit of easystart.
do I need to have battery connected? althou cannot see how it would help,
any ideas would be appreciated before I go to plan b, actually there isnt a plan b so I’M BANKING ON YOU GUYS
Help! on going cafe racer/860 project
got it going this evening , wasnt getting the engine turning fast enough, was a bit apprehensive with kickstart, put my motocross boots on and gave it some welly and hey presto!! although i have some serious bruises on my shin from my attempts in trainers .
So now know that all the ignition bit are all in the right place, a bit smokey to start with but seems to be burning off.
exhaust leaks abit, cannot get the castillated nut on manifold tight enough and dont have the proper tool!
can set to work trying to adjust carbs,but should be straight forward( famous last words).
so another day in garage, if its raining , should see some progress.
Thanks everyone for help so far, but dont go away!
Mdina sell the correct tool they’re a bit expensive though at £40.
Still I dread to think how much the exhaust nuts cost these days.
If you don’t have the nut tight two things will happen:
- You’ll spit flame out of the silencers on a trailing throttle - looks great
- The loose, vibrating nut will wear the threads resulting in needing a repair - not good
Make sure you get it tight before using it too much.
Many of the tools do both the singles and twins so if there are any bevel owners of either type in your area they may be able to loan you one.
Where are you?
As well as Mdina Italia there will probably be a couple of people with tools at the Stafford bike show in October, as well as new nuts (and gaskets) if you need them.
Many thanks Roger,
have made my own tool from an old preload adjuster and it fits perfect.just waiting on some bits off ebay to finish electrics and should be nearly ready to try out on a quiet road before mot.
Screwdriver and a whack with a hammer will tighten the exhaust nuts.
Won’t look too pretty afterwards though.
I bought a tool (Can’t remember if it was Mdina or TB) but it does singles and twins.
Having said that a mate has made one from cutting an old exhaust nut in two and welding a bit of metal on to one half as a handle.
Doesn’t look a work of art but seems to work ok and cost him nothing!
Also if exhaust nut is not tight enough you will draw air through and play havoc with your carb settings.
And as Roger says will breathe fire.
(I was also told to fit new exhaust gaskets when refitting the exhaust.)
I’ve owned the correct tool for some years now, but before that I’d use a short length of alloy tube cut from an old RT London Bus handrail, which I’d lightly/carefully tap with a hammer…
I never broke or bent any fins from the exhaust nuts using this.
I found that XT 500 Yamaha exhaust gaskets work well and lasted longer than genuine Ducati items,
I now use solid copper washers instead of exhaust gaskets when I fit my S/Steel system, I’ve also used some lovely copper/asbestos exhaust gaskets that I found at Brown Brothers for pennies, they were on a display board of generic car exhaust gaskets.
I went down the route of looking for substitutes for the OEM items, because the original and most pattern ones masked part of the exhaust port.
There seemed little point in having a larger bore ID down pipe as fitted to the 900SS then masking the entrance to that pipe with the cr*p OEM undersized ID gasket.
Masking an exhaust port in this way has been used to restrict engines in the past, the down pipes fitted to the Darmahs and possibly the earlier GT/GTS 860-900 were double skinned and restricted the motors.
It’s little snippets like this that get you thinking.
So obvious, but I’d never thought about it before. Might be something to consider if I ever do a big renovation job on the DarmahSS.
Hi to all, two things going on.
a) my exhaust is now fully tightend thanks to my new exhaust nut spanner(read honda firestorm pre load adjuster and extension piece) and newly made crush washers .it fits a treat.
b) carbs are so far out cannot get a decent setting to start from so they will be off again and I will get some NEW jets and other bits and start again. Any advice on basic set up for PHF 32’s appreciated.
The engine will start but as soon as i let choke off it cuts out and very smoky on front pot, have fiddled with mixture but think problem is deeper and as I dont know history of carbs and engine is now closer to 900cc need advice?
Having said all that at least it looks pretty good now that all the bits and pieces back together, but still needs a speedo, does anyone know the ratio
bye for now cheers phil
Why not fit it with a pushbike speedo, one of the little digital items they’re very accurate, completely legal, they’ll read upto 180mph (Not that you’ll ever need that facility) and cheap!
Read here about £20 for one that tells you the speed, average speed for journey, time spent on the ride, maximum speed attained, trip milage, total milage and the time of day…
You can get them from Halfords, Sigma is a pretty good make.
I’ve used them for years.
Ohlins/Harris shock adjuster spanners are also a perfect fit, though they only work on one fin at a time. Also drill a hole in one of the nearby cooling fins and lockwire it.
Blimey … Where to start?
The factory specifications for jets and needles are given in many of the standard reference works and/or factory publications. The good news is that, in general, the full suite of replacement parts are still available from Dell’Orto, with the exception of slides.
The carbs need to be absolutely clean, especially the small drilling that supplies air to the idle system. This is easily over-looked, leaving people mystified as to why their ‘re-built’ carbs won’t idle. It can be clogged with a very tenacious petrol residue deposit which can be extremely difficult to clear without an ultrasonic bath.
The float heights must be right. If they’re too high, the engine will run rich or won’t start. Too low and it won’t run, or will falter or misfire.
The piston in the cold start enricher circuit (aka erroneously a ‘choke’) must seal effectively. The rubber seal at the bottom hardens with age, allowing too much fuel to enter the system and making it impossible to get an idle.
The pumpers need to be calibrated to deliver the right amount of fuel. The diaphragms fail with age, and people fiddle with the settings, even tho’ the ‘adjustment’ screws are painted in an effort to deter the unwary.
If the slides are excessively worn, you’ll get air leakage, making tuning at slow throttle openings difficult.
You MUST balance the carbs carefully if you want an even tick-over.
Dell’Orto’s own handbook is a valuable reference source as to how the carbs work and therefore what you are trying to achieve. Try this link filejumbo.com/Download/E9A7373D7DA0566F.
If you’re not absolutely confident in your abilities, you might want to consider getting the carbs overhauled by a specialist - Mike Davies at JRS, for example. Not especially cheap, sure; but 100% effective.
Have you done either a compression test or, better, a leakdown test? This can help pin-point where oil is getting into the combustion chamber from.
These engines can suffer from valve guide wear - the guides were always a bit too short and if the oil hasn’t been changed as it should have been, this could be the result. Unfortunately, the rockers are normally damaged too
If the engine was stored for any length of time, the bore on the front pot can get rusted up. If so, you could be looking at a new liner, plus piston and rings - gulp!