t140e forks and oil pressure

I have finally finished my Rickman Metisse, photos to follow soon. 2 things on commissioning have cropped up.

firstly, on kicking it over for the first start the oil pressure went up to 60+ psi, on starting, stopping and starting again it settled at 20psi and seemed to drop on revving, the oil return was, and still is, impressive coming back into the frame return, I am going to connect a spare gauge and try to eliminate the new one having a fault, also for a brief period after about 5 mins both exhaust were emitting a lot of white smoke, oil I am thinking, this seemed to clear after restart a bit later. the engine has had a full rebuild, re ground crank, new pistons and rings, honed barrel, all new bearings and seals etc,

secondly, the forks have been re built with new seals, new stanchions, I am sure new springs as well. After compressing, they don't return to full height, I have to pull them back up to full height. I have loosened off the front wheel, bounced about and tightened clamps.
I don't seem to have any bits left over, but it seems that a spacer or something has been missed on my part.

Any suggestions welcome please, deflated at the moment after so many hours, weeks and months and plenty of frustration, but I have really enjoyed the whole process and learnt so much, just need that final bit sorted, thanks Neil.

mudplugger said:

firstly, on kicking it over for the first start the oil pressure went up to 60+ psi, on starting, stopping and starting again it settled at 20psi and seemed to drop on revving,

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Three possible causes of a sudden drop in oil pressure can be due to the crankshaft oil seal inverting (lip turns inside out), the OPRV could have stuck open, or a small piece of dirt or metal swarf stuck under the feed pump ball valve.

mudplugger said:

the oil return was, and still is, impressive coming back into the frame return,

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If the crank seal does become inverted, then a certain percentage of oil will go straight to the sump without passing through the crankshaft so you would still see a good return flow, however, this is just one possibility.

mudplugger said:

secondly, the forks have been re built with new seals, new stanchions, I am sure new springs as well.

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Who rebuilt the forks? You might be sure they are new springs but are you sure they are the correct springs?

mudplugger said:

After compressing, they don't return to full height, I have to pull them back up to full height. I have loosened off the front wheel, bounced about and tightened clamps.
I don't seem to have any bits left over, but it seems that a spacer or something has been missed on my part.

Click to expand...

There's no spacer in the standard T140 fork.
A couple of suggestions.

The damper O-rings (97-4003) can be the cause of a 'sticky' fork action. There are better phenolic replacements for the standard O-rings.

Which type of fork seals?
If they are the original '78-on 'self-aligning' or 'leak-proof' type with interference-fit metal 'retainers' (like a large washer above the seal) then the retainers must be fitted so there is a gap below the retainer so the seal is free to 'float'. If the retainers are pressed down hard against the seals it can cause the forks to stick.

People have also been known to fit the crank oil seal backwards.

Thanks for the info, I did all the rebuilding, so could have easily made a silly error, at least I now have some places to start looking. will let you know how I get on.

That's a bit of a bugger but you'll get it sorted out I'm sure. It's just frustrating after all the work. Good luck.

Jg

Oil pressure is back. 55-60 on tick over. I took the cover off and checked the oil seals, all correct. stripped the oil pump and blasted thru with air line, nothing obvious. stripped the pressure relief Vv, this was very tight. changed the oil pressure gauge. put it all back together. good pressure straight away. original gauge back on, still good readings.
Struggling to get the digital rev counter working now, right pain in the ar... haven't tried to sort the digital speedo yet.
Also trying to get the single Makuni set up right. the joys of building your own I suppose.

The joy of building your own, but what a way to learn about your very own bike, how many spends heaps on someone else building their bike and still have no clue in what is happening with it, also other engine builders do make mistakes, its human nature, something simple could cause so much trouble, its all part of motorcycling, but you are getting there, now have some fun on it.

Ashley

Glad you got it sorted!

Good luck with the Mikuni, it seems to be that these are good carbs when set up well, but can be a challenge to set up well!

What clocks are you using? I've got electronic Smiths units, I was really daunted by the job of fitting and setting them up, but when got my brain in gear and plodded through steadily, it was all quite fuss free.

The Mikuni is a good carb but the carb I have was shit on one bike ,great on another . It's a great feeling working through the " list" and getting things working....and then the shakedown runs. I am doing a seventy miler tomorrow a few adjustments then it's off to Dynatech. Good job on the bike mudman .

Jg

It certainly is a good way to get to know the bike, I think the jetting is out on the carb, it came with a 250 main jet, I think a 230 is required. the tick over screw is also wound right in to achieve a normal tick over, this should sort out as I get the jetting correct I hope. will look at the slide as well.
The speedo and tacho are smiths digital. the wiring instructions have the colours and connections wrong, the needle is now moving round but I have to get the set up correct, it is a bit of a ball ache, I have tried all sorts but will persevere and keep phoning the supplier if needs be, he is very helpful (and patient). I hope the speedo is easier. just need to mark out a mile straight near by and try it.

MOT today, had about 10 mile run on it at the weekend, feels really good, tweaking and tightening now.