Ebrightstar
New Member
Hi Folks,
Problem: Ski is running very rough and not revving up but running just at idle. Engine dies when you try to rev it.
Rotary valve and crank seals not in great condition as they will leak.
Background: Ski sat outside for 7 years untouched until two months ago when we started working at it.
Over the 7 years, oil from the oil tank feeding the rotary valve had leaked into the crank and also further into the flywheel chamber.
Action taken:Removed remaining oil from oil tank and cleaned out flywheel chamber and stator, removed twin carbs and turned ski onto its side to drain all oil out, then refitted the carbs correctly.
Disconnected the large clear oil lines (that come out from either side of the engine) from the oil tank and filled them with thicker oil and connected together to ensure the rotarty valve was lubricated and to prevent leaking through the seals as experienced with the thinner engine oil.
Left oil pump at rotary valve untouched and still connected to sync with throttle cable.
Mixed 40:1 premix and placed it into the fuel tank.
With the air filter off, good engine compression, a good battery, and original tempo fuel lines (which had no signs at all of deterioration) I started the ski and it went perfect revving up each day over a week with no problems at all.
The ski had been ran on the garden hose for cooling purposes and the hose disconnected before the engine was turned off.
Upon leaving the ski for a few days and trying to start it, it would not start. So we thought it was fuel related i.e. not getting enough fuel. So we used a compressor air line to help pressurise the fuel tank but sadly unknown to us at the time we had loosened a few fuel lines causing an air leak at the fuel vent/res/return cap etc. This resulted in no fuel at all getting to the carbs so we took off the carbs and stripped all down and filters were clean, all diaphragms and check valves and jets and needle good, no damage etc etc at all - all parts were sound. So we reassembled the carbs and refitted and no change - still no fuel getting to carbs. So we then noticed loose clips on different fuel hoses so replaced all hoses and clips with screwable jubilee clips ensuring all hoses inclusing pulse lines were tight functioning.
This resolved the fuel issue and the ski started again but instead of running properly and revving fully it was running like crap - very weak and rough - sounding like a tractor.
New plugs made no difference.
Exhaust was checked for issues and none were present. We then fully installed the flame arrestor to check for any noticeable change and we noticed only a very very small marginal improvement when starting the ski again.
We then took the head off the engine and noticed a grey oil mixture on the pistons and cyclinder walls as if water had got into the chamber or crank causing an emulsion.
Is there somehow some water getting into the crank or combustion chamber hindering combustion or is the cause that the old worn rotary valve/crank seals are sucking in air as when the engine starts and we open the throttle to rev it, the engine dies. It only runs at idle and accepting minimal revs.
Any ideas folks?
Problem: Ski is running very rough and not revving up but running just at idle. Engine dies when you try to rev it.
Rotary valve and crank seals not in great condition as they will leak.
Background: Ski sat outside for 7 years untouched until two months ago when we started working at it.
Over the 7 years, oil from the oil tank feeding the rotary valve had leaked into the crank and also further into the flywheel chamber.
Action taken:Removed remaining oil from oil tank and cleaned out flywheel chamber and stator, removed twin carbs and turned ski onto its side to drain all oil out, then refitted the carbs correctly.
Disconnected the large clear oil lines (that come out from either side of the engine) from the oil tank and filled them with thicker oil and connected together to ensure the rotarty valve was lubricated and to prevent leaking through the seals as experienced with the thinner engine oil.
Left oil pump at rotary valve untouched and still connected to sync with throttle cable.
Mixed 40:1 premix and placed it into the fuel tank.
With the air filter off, good engine compression, a good battery, and original tempo fuel lines (which had no signs at all of deterioration) I started the ski and it went perfect revving up each day over a week with no problems at all.
The ski had been ran on the garden hose for cooling purposes and the hose disconnected before the engine was turned off.
Upon leaving the ski for a few days and trying to start it, it would not start. So we thought it was fuel related i.e. not getting enough fuel. So we used a compressor air line to help pressurise the fuel tank but sadly unknown to us at the time we had loosened a few fuel lines causing an air leak at the fuel vent/res/return cap etc. This resulted in no fuel at all getting to the carbs so we took off the carbs and stripped all down and filters were clean, all diaphragms and check valves and jets and needle good, no damage etc etc at all - all parts were sound. So we reassembled the carbs and refitted and no change - still no fuel getting to carbs. So we then noticed loose clips on different fuel hoses so replaced all hoses and clips with screwable jubilee clips ensuring all hoses inclusing pulse lines were tight functioning.
This resolved the fuel issue and the ski started again but instead of running properly and revving fully it was running like crap - very weak and rough - sounding like a tractor.
New plugs made no difference.
Exhaust was checked for issues and none were present. We then fully installed the flame arrestor to check for any noticeable change and we noticed only a very very small marginal improvement when starting the ski again.
We then took the head off the engine and noticed a grey oil mixture on the pistons and cyclinder walls as if water had got into the chamber or crank causing an emulsion.
Is there somehow some water getting into the crank or combustion chamber hindering combustion or is the cause that the old worn rotary valve/crank seals are sucking in air as when the engine starts and we open the throttle to rev it, the engine dies. It only runs at idle and accepting minimal revs.
Any ideas folks?
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