Ransomes marquis Throttle adjustment
Just bought a Ransomes marquis. With a 3hp b&s engine , start well and idles but the throttle lever moved and the slider at base of engine but does not seem to open throttle , spring is attached to govner , not sure if I need a tighter spring or if I'm missing one . Any advice welcome .
Not the easiest thing to photograph . I’ve got a spare Marquis spec BS engine which I will try to dig out later but in the meanwhile please post the Model, Type and Code numbers which are stamped into the BS engine cowling, probably on the vertical face opposite the petrol tank. That will ensure that any information is relevant to your engine build.
Ok. 80232. 8634. 01. 85060603. Thanks
Ok thanks , it looks like maybe a control rod is missing mmm.
Interesting about the rod as if it's the long one, i had to make one . The spring that goes around it is still available but the rod not so. Took these this pm before reading about the rod . Which id number on the IPL are you missing.?
The spring around the rod is not vital but it keeps the linkage in tension and to some extent stabilises it.
Unfortunately with all the throttle/ Governor linkage being tucked away behind the tank it’s a bit difficult to explain but.......
The internal Governor spindle exits the crankcase and carries the Governor arm . The mechanism always tries to close the throttle. That closing action is resisted by the Governor spring which is tensioned by the handle bar throttle control. The end of the Governor arm is connected to the bell crank at the top of the fuel tank by a long link running vertically behind the tank.
If all that is in place your issue could just be that the throttle cable is out of adjustment and not tensioning the Governor spring enough to resist the closing action. It may just need the cable from the the handlebar control to be moved in its clamp to put more tension onto the spring. The mechanism won’t work without the cable in place.
Ok thanks for detailed reply , I have now adjusted throttle cable but it still does not put enough tension on spring , so I'm thinking maybe to try to adjust spring get get slightly more tension , or try different spring .
One thing that I didn’t mention is that there is a maximum speed adjustment screw tucked away behind the fuel tank . Quite a long vertical screw with a compression spring around it. Part of the linkage, not the carburettor .
I will try to post a marked image later, but it’s clearly visible in the second and third from last images that I posted earlier.
At last managed to get a guvnor spring today for my local mower spares place on Basildon the guy in the shop Ian even new about my version of the ransomes mower and that the Briggs and Stratton engines were a special batch slower reving, the original brigs reved too fast and clutch kept engaging . He had the spring in stock for 25 years , . Seems to have done the trick although I had a guvnor spring it was out of shape .
I hope that solves your problem but the explanation that your man has given is a bit adrift from the situation as we knew it at the time when those machines were current. The BS engine was not happy idling at much less than the recommended 1750 rpm . Drop the idle much lower than this and when asked to accelerate it would bog down and stall: so lowering the idle rpm was not the answer.
The issue was that the Marquis’s centrifugal clutch had been matched with the low idle speed of the previous Villiers / BSA F12 engine that would accelerate without hesitation from 350 / 450 rpm. The answer to the incompatibility with the BS engine was not to attempt to get it to idle below its “ sweet spot” but to raise the engagement point of the centrifugal clutch to accommodate it by fitting stronger clutch springs. Existing machines with the issue could be cured by ordering and fitting the stronger springs which to all intents looked identical to the lower strength ones, but I was recently working on a BS engined machine with red painted springs, so I assume that in later production Ransomes had the sense to make that distinction .