ThornyCroft T-90

Update: 1.) I read the instructions on adjusting the throttle lever but do not have the aptitude to make the adjustment as I had difficulty in separating the cable unit from attachment point and did not want to screw it up. I do not know how to adjust the throttle cable and may need a mechanic on site because: A.) (Note: the Shut Off Lever which normally has a cable from the helm instrument panel to shut off the engine from the cockpit is now shut off directly by hand on the engine as the shut off cable was damaged and removed) The Shut Off (fuel) Lever seems to be moving downwards to the 'on' position on its own more readily compared to before when you pulled the lever back to cut off the fuel it would seem 'stiffer' and stay in the 'off' position. I still push it down all the way before starting the engine it just seems 'looser' and more prone to want to be in the 'on' position. (Note: the fuel cut-off cable from the instrument panel was removed and the fuel lever to start the engine is moved 'UP' position directly by hand now) B.) Normally, 'idle' is when the throttle at the helm is in the upright position. I have noticed that when starting the engine by giving it fuel/ pushing the helm throttle forward....the engine receives fuel in a greater amount as it quickly revs up as if alot more forward push of helm throttle....I have to quickly pull it back to the neutral position but even then it does not idle at the usual 6,000 rpm but it idles at 8-9,000 rpm's even when the helm throttle is pulled back into the full- upright' clicked 'neutral position. Thus it appears to be a cable adjustment which I dont seem to be able to do- As for identifying the source of the leaking fuel: The process I did: 1.) I started the engine up the leak appeared once the rpm's hit 2,000: (see above schematic) Number 48 'screw for cover' over the 'adjusting hole cover ' (46) of the Pump Housing (44) was leaking fuel. The wire that normally runs through it was broken off and the 'screw for cover' was extremely loose and exuding fuel. I used a 5/16' wrench and was surprised that it tightened over a full revolution. It was very loose. I then started the engine again....and let it run at 2,000 rpm's for a while.......no more leaking. However, there was still a scant fuel leak, minimal, between the Shut Off Lever (82) and the Shut Off Shaft but 98% or more of the leaking fuel was coming from the Screw For Cover (48) over the Pump Housing, but nowhere near the amount that was flowing out by the 'Screw for Cover) #48 over the Pump Housing. Also---the wire that used to go through the screw has been broken off.... Upon running the engine at 2,000 rpm's after tightening that 'Screw for Cover' (48) no more fuel leak- however, i did notice that when i pulled the helm throttle back to neutral.....the engine was idling at 8-9000 rpm's whereas before the new throttle cable was installed in the same position at the help at neutral the engine idles at 6,000 rpm's. here are some pics:

Im going to start the engine up after work today and spend some time with a white tissue dabbing to see exactly where it all is coming from- i will post the pics later tonight - you are 4.5 hours ahead of us...so 7:00 pm our time is 11:30 pm your time- Im also going to see if I can follow your post #7 so I will have alot to report back- Thanks again-

I just pulled out the original 'ThornyCroft Operations Repair manual' which I 'inherited' when I bought the boat 3 years ago....this notation would have been written at least ten (10) years ago. Note it says 'seems to be leaking past 89 needs 15/15" wrench'

Tony, I will run the engine and dab and report back- Your reply jogged my memory which may help in diagnosis: Everything was fine - about a year ago I had a mechanic install a new gearbox and new cables. He did not adjust the cable to the gearbox properly...he clearly was not experienced. I also noticed that the cable to the throttle lever kept making the throttle by the helm 'pull back' to idle whereas before he installed the new cables when you pushed the helm throttle forward it would stay wherever you pushed it to once you took your hand away. But after his job I had to hang a pound of heavy rope on the end of my helm throttle to keep it in place so as to keep it at whatever RPM I wanted to run it at. I am hundreds of miles away now from that mechanic so he cant adjust it- Now, there was no leaking for about 25 hours of engine use but three days ago I noticed that when I started the engine the RPM's went super high whereas normally when I bring the throttle to neutral the idle seed is about 5-6,000 rpm's. I also noticed that enroute the throttle did stay in place -- it just felt 'screwy'- I am certain now that the mechanic did not adjust the new cable correctly as he did a very sloppy job on the gearbox cable which i called him and had him come over to fix which he did....but I did not notice the poorly adjusted cable on the fuel lever until many hours away and many states away- Tonight I will re-run the engine and see if we cant pinpoint more specifically where the leak is originating. Thanks again for your input- it is invaluable -Vin

Thank you so much for replying. We are stuck here and still trying to assess where the fuel is spilling from. Here are some pictures from where the spill seems to be generally located. It started all of a sudden...the first day there was maybe a cup after 6 hours of journeying....then yesterday much more after only 1 hour so we turned around and are stuck here at a marina. Anyway, here are the pics of the general area--thanks for looking at the pictures and I certainly welcome your help in problem-solving. Once I can figure out what is wrong...then I can maybe fix it myself or look for a mechanic but we are in the middle of nowhere in an isolated part of the region:

Hi all! Just joined the group- I have a ThornyCroft T-90 in my home...a 1983 Moody 34. Just found a bad fuel leak...on the starboard side near the fuel lift/fuel lever area... anyone have a similar problem? I just want to get more education before I call a mechanic here...especially since maybe in the States they are not so familiar with the BMC 1.5 Thanks so much for any input! -Vin my channel: Sailing Nervous