low compression?

I was wonderng if you could provide me with some advice. I have a 1973 500C backhoe, and at the time of purchase 2 years ago, it just had a newer (used) motor put in it. The fellow I bought it from bought a used farm (dyno specs were near new)tractor motor complete, and installed it. He showed me the bill for the motor alone it was near 7000.00 Can$ with frieght.

The reason I write this is:

1) I cannot seem to get the beast started without ether. In summer or winter. In winter, if it is not plugged in, it is much much worse. After it has run for a minute or two, it will start easily with no ether.

I recently discovered that I can start it wihtout the hydr pump engaged. That makes a definite difference, but i still need ether. A friend of mine told me I need ether all the time because I have low compresson (rings are shot), but I dont think this is true because it seems to have plenty of power when runnning. ????

2) I live in northern Canada and I have decided to try running Chevron Delo 5/40 synthetic oil for easier starting on this backhoe and my elderly (1955) tractor. The same fellow I bought the hoe from said to always use 15/40 wieght oil in it. What are your opinions on this situation. I would feel pretty stupid if I were to do some serious damage to either motor from using this synthetic oil.

3) Hydraulic hoses on the backhoe are in pretty bad shape. I have some fairly big plans this summer for it, and was going to change some hoses now, before they broke when I least needed a breakdown (and 45 min drive to town one way). Is this a good idea, or should I just wait until they break? Does a guy ever regularly replace these things? Some of the hoses have no outer rubber left, and the metal braiding is visible. I guess it would make sense to replace the ones that are weeping first.

ok, thats enough for now. Thank you, hope your winter is going well.

No, it does not smoke white when cranking over - it blows black smoke (not a huge amount - unburnt fuel?), but I usualyy have the hand throttle set at 3/4 and give a good shoot of ether. I have to repeat his process about 3 times before the motor will stay running after backing off the throttle. I just replaced air filter. Maybe I'll replace fuel filter too , and have a look at the injectors. Roughly how much should one expect for an injector re&re?

I also wanted to ask where would a guy get a compression tester for a diesel - something that would go above 400 psi for a reasonable price?

As well, I forgot to ask, I got given a good pair of grader chains for this machine, but cant use them due to lack of clearance between the inside tire and cab fender wall. I was told to look for some spacers, but when I called the JD dealer, he said they never made spacers for this model. All I need is about a 3/4 inch. Any ideas?

Thanks again,
john