starting under load

[simon 1]

Hello everyone I'm new
I have just brought a sawbench with a lister I think its a lr or an st this will start with no problem when the bench not conected but when I put the belts on she don't want to start unless she has been running for ten mins with out them I would be greatfull if someone could help me please

[LowGear]

Lube them bearings?

New belts?

Align the belts?

How big of bench saw do you have (belts)?  What the dickens is a bench saw?

Casey

[simon 1]

hello there not sure what you mean bench saw ??
but the saw bench is run of 2 belts like normal fan belts i have aligned the belts added new belts only thing i haven't done is grease the bearings i haven't done this as when it hasn't got the belts on there the blade seems to run freely but when the belts are attached you can feel the difference when trying to start the engine... i didnt know if this meant the engine has had it ???it does seem to have loads of compression!!!

[Combustor]

Hello simon1,
                 If you are starting your motor in a cold climate it will need to spin over fairly smartly to acheive easy starting and the additional bit if belt friction may be preventing this. Check that the pulley groove profiles are not visibly worn, as new belts in worn grooves could cause extra friction load. Excess belt tension is another cause of power loss. Run just tight enough to drive a full load without slip. One solution could be to set the belts slack for starting and then tension them with an idler pulley on the non-drive side.
         Does your engine have an oil priming cup on the head by the intake port? For easier cold starting fill the cup with engine oil and push it into the intake to raise compression for cold starts. this may be enough to make a difference.
         If your setup is not factory original, check that  (a) pulley ratios are correct to give correct peripheral speed for your blade size,
                                                                           (b) pulley sizes are at least minimum recommended for belt section used.
                                                                            A section pulleys minimum 4", but 6" is better.
                                                                            B section pulleys minimum 6",  bigger is better.
         Hope this helps,  Regards,  Combustor.

[listard-jp2]

  I think its a lr or an st

If its a Lister LR1 from say a cement mixer then you only have circa 1.5BHP to play with, and unless your starting the engine with the start lever in excess fueling position I am not surprised that you are experiencing the problems you describe. Are you also using the oil injection plunger on start up as well?

If its a Lister ST1 then I am surprised by your comments as that could be as much as 10BHP, and unless its well worn should easily start with the saw bench belted up-to it.

Is there a noticeable difference between cranking the engine over when it is, and is not belted up-to the sawbench. If so then its likely there is a problem with the saw bench.

I myself have a Petter AVA1 permanently belted up to a sawbench, and it starts from cold easily, and in the summer months it will start without lifting the excess fuel pawl.

[simon 1]

hi there

im sure its 1.5 bhp model i did try using the plunger as thats how i used to start the road roller but it didnt seem to like it but that was when i first got it so dont know the history aof it really before but i havent tryed it since i have put the new belts on it !! i will give it a go 2morrow with the plunger..
also i was given a lr1 4.25 bhp as a spare enging i have tryed to start this engine thought it would be better for the benchi have changed the oil bled the diesel system and the first time it fired but that is all it seems to do i have had it run for about 5 seconds but the revs didnt really pick up then dyed its done this twice and just wont start have you any ideas??
 thanks

[Combustor]

Hi again simon 1,
                      If you do indeed have a low speed (low power) LR1, you can increase rpm on the governor setting  by a fair margin provided that you reduce pulley ratios to take advantage of the extra power at the higher rpm. A change of governor weights and springs  and pump timing will allow speeds up round 2200 rpm or so from memory.
          If you do have a larger motor available you will still need a pulley change if it runs at higher rpm to keep your blade in a safe speed range and utilise the extra power. Your other LR1 possibly still has air in the fuel pump, as they can be a pig to bleed properly. Need to remove sidecover to access bleeder on the pump, and also loosen injector pipe connection under rocker cover,(difficult). Will only start when you can hear the injector giving a healthy "creak" when cranked over. Good luck,  Combustor.