Oil lamp blinking + bad starting when hot

I have swapped engine in my VF1000F (snapped camchain in the old) and been riding the bike for a couple of days. The engine runs sweet an strong but when warm the oil lamp blinks at idle (1000 rpm). I was stupid enough not to check the oil pump on the “new” engine…
My plan is to first change oil filter (I have an old one because I’ve got an oil mod and an unknown filter on it, a smaller). I use fully synthetic 10-50 oil; can this cause the symptom? Next I will pull the sump and check the oil pump and the pressure relive valve. In worst case I will use the oil pump from my old engine since I know it’s okey.
Any thoughts or tips so far?

Next item is one the I had also with the old engine (befor swapping); when hot it’s reluctant to start even with a fresh battery. Seem like the heat causes resistance to increase somewhere. My prime suspect is the long cable from the battery to the starter motor. The starter motor is from the “new” engine.

Anyway I’m happy today since it passes MOT with no remarcs whatsoever! [:)]

Can’t help with the oil problem, but I had problems with starter motor last year and sorted it this spring. I had stripped and cleaned up starter motor last year as it was very sluggish to start, worked well for a while but battery drained whilst out on run, a few embarassing push starts needed. I checked all the wiring and charging circuits, thought that the regulator was my problem, so bought a new one and new battery, seemed ok on last couple of trips last year. This spring problem started again, I was a bit befuddled by now, I fitted an ammeter to starter circuit and found that the starter was taking a massive load from battery, only allowed a couple of starts on a run out and battery was so drained it would take a long run to put any juice back in. Got hold of a used starter, fitted yet another battery ( Gel type) . I have done nearly 3500 miles since with no problems at all, conclusion, starter motor. I see that starter repair kits are available from the states on e bay http://www.ebay.co.uk/itm/270527429634?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649#ht_1365wt_1397 Good luck…

I pulled the starter motor yesterday and cleaned it. It was a lot of graphite dust inside but the brushes were OK (9 mm, limit 6.5 mm)). I did find a lot of oxide on the three tabs (on the plate that holds the brushes) that pushes on the inside of the end cover of the motor and corresponding oxide pits in the cover. I cleaned that and perhaps that will do it. Havent tested starting the bike hot yet. Starts very easy when cold now. I also checked the rotor (commutator) with a multimeter and it seems OK.
I measured the solenoid when activated and got zero ohm. Cleaned all the associated contacts and finally measured the long cable from the solenoid to the motor (it was OK).

I did all that you have done as well, theoretically should have been ok but the cure was a fresh starter. Just been looking on e bay, there are a number of starters available in USA but on the VF750 listings, it is I believe the same motor. Good luck, will keep a check on yr progress on here.

I had a similiar problem and fitted new brushes which did the trick.

new brushes and a major clean in side sorted my starter[:D]

After the cleaning of the starter it now work as new!
Back to the oil problem:
First fix was to raise the idle to just above 1000 rpm. No blinking oil lamp after that.
Next thing was fitting an oil pressure gauge and a new filter.
When cold I get 6 bar at 5000 rpm, warm 5 bar (the temp gauge needle is just entering the wider band at the dial) and hot (97 deg Celcius oil temp) returns 4 bar. The manual says that at 5000 rpm and 80 deg Celcius the pump should give 4.6-5.7 bar. I guess that mine pass the test. I use full synth 5W-50 oil.
Perhaps the pump is near its service limit since the engine have more than 80000 km under it’s belt? I have the old engine loose so I can pull that pump an measure the clearances to see if I would benefit from a swap.

Hi, Lasse
I would first try with oil recommended by manufacturer (10W40) and then maybe change the oil pressure sender, and third go to oil pump itself. I checked the pump from en engine with 95000 km, and it was still within specs. Missing oil pressure can be also caused by too big bearing alignment, but I bet that this would give some sound too.

[:)]remember this is old tech and it is best to run it on older types of oil.
My old Yamaha XJ1100J Maxim runs on 10/40 semi synthetic, Its not designed for super high grade full synthetic oil.look in the manual its available on this site for free.
My max burned a little oil on the best stuff but on the older oil it stopped burning all together.

get the right oil

Mr Honda still knows best He [:D]spent a lot of dosh making these bikes