help me please

[waynemags]

im new to the forum. and new owner. i just picked up a 1980 720 bobcat. was not running. it was supposed to have been running before being parked a few years ago. like a fool i trusted this guy. when i was getting ready to do a compression test, my wife called me crying that my dog was laying on the floor withe her insides out. result of a previouse surgery. needless to sy i rushed to get home as we were 3 hrs away,. now ive got this thing home. it has two cylinders that show zero and two that are around 50 psi. also im pretty sure theres a broken rod. i know i know, buyer beware. point is now im stuck with this heap. wondering if anyone knows where i can get a replacement engine for it or if there is a different ebgine that will fit. i wish i would have done the test but she was screaming and crying hysterically. so i had to turn and burn. looking to fix this thing now that ijm stuck with it so im looking for options. its a VH4D gas engine. any help would be great. about the dog, i had to shoot her when i finally got home. her guts were laying outside her body. apparently the vet didnt stitch her very well. what a day. hope someone can give me some info on where to start looking. thanx

 

[OldMachinist]

The zero compression could be just a blown head gasket and the low ones might have stuck rings from sitting. Why do you think it has a broken rod? Rebuilt engines for these are around $4000.

 

[Tazza]

The zero compression could be just a blown head gasket and the low ones might have stuck rings from sitting. Why do you think it has a broken rod? Rebuilt engines for these are around $4000.

The other thing to check is the valves. If it has been sitting, its possible you have slightl stuck open valves not giving you compression.
They may have said it used to run before sitting, but how well was it running? it could have been running, just very poorly....

 

[waynemags]

The other thing to check is the valves. If it has been sitting, its possible you have slightl stuck open valves not giving you compression.
They may have said it used to run before sitting, but how well was it running? it could have been running, just very poorly....

it fired , ran for a few seconds and bang. now the crank wont rotate 360. popped the heads off and the one piston i think #3 hole has aluminium or something embeded in the top and in the head. looking at the motor from the back the cylinder on the left front toward the seat is oil soaked. the one on the right rear toward the rear door is the one with all the stuff embeded. now the crank wont turn complete rotatioin. im guessing at the broken rod. he told me that he had it running no problem by priming the carb. i found a broken coil power wire so im not sure how he had spark. must be a magician. im so pissed at myself for getting in this mess. but now here i am. is there a different motor that will fit

 

[Tazza]

it fired , ran for a few seconds and bang. now the crank wont rotate 360. popped the heads off and the one piston i think #3 hole has aluminium or something embeded in the top and in the head. looking at the motor from the back the cylinder on the left front toward the seat is oil soaked. the one on the right rear toward the rear door is the one with all the stuff embeded. now the crank wont turn complete rotatioin. im guessing at the broken rod. he told me that he had it running no problem by priming the carb. i found a broken coil power wire so im not sure how he had spark. must be a magician. im so pissed at myself for getting in this mess. but now here i am. is there a different motor that will fit

You can't rotate it 360 degrees with the heads off?
Parts for these engines are still available, they are a good engine, it may be worth doing it up.... Sounds like it needs pulling and take the sump off and see just what's going on.

 

[waynemags]

You can't rotate it 360 degrees with the heads off?
Parts for these engines are still available, they are a good engine, it may be worth doing it up.... Sounds like it needs pulling and take the sump off and see just what's going on.

no i cant rotate it. i got the engine out today. havent opened it up yet. will do it tomorow and post what i find.

 

[waynemags]

no i cant rotate it. i got the engine out today. havent opened it up yet. will do it tomorow and post what i find.

broken rod clamp. damage to the cylider and piston. what a mess.

 

[waynemags]

broken rod clamp. damage to the cylider and piston. what a mess.

ok. now on the front of the engine toward the cab theres a cooling shroud around the engine. in front of the timning cover. how does this come off? i have no manual and have been winging it this far. does anyone have a manual on pdf file i could pay for

 

[OldMachinist]

ok. now on the front of the engine toward the cab theres a cooling shroud around the engine. in front of the timning cover. how does this come off? i have no manual and have been winging it this far. does anyone have a manual on pdf file i could pay for

Give me you email addess and I'll send you the manuals you need. My email address is in my profile.

 

[tnt6060]

Give me you email addess and I'll send you the manuals you need. My email address is in my profile.

sorry to hear about your bad luck I think all of us have been in that boat once or twice. I saw a couple of these engines on e-bay one was Item # 220759702751

 

[OldMachinist]

sorry to hear about your bad luck I think all of us have been in that boat once or twice. I saw a couple of these engines on e-bay one was Item # 220759702751

If you decide to buy another engine make sure the output end of the crankshaft is correct. I remember someone saying that the Wisconsin in the Bobcats has a tapered output shaft.

 

[waynemags]

If you decide to buy another engine make sure the output end of the crankshaft is correct. I remember someone saying that the Wisconsin in the Bobcats has a tapered output shaft.

ok. ive decided to buy a longblock from wisconsin dealer in ontario. now i noticed that aft6er i put hyd oil in before thhis all happened, the started to be a good leak on top of the hyd motor that attaches to the wisconsin motor. looks to be thge main hyd motor. hydrp pump. im gonna start taking hoses off and look for filters. is there a possibility that i blew something or worse broke something? i added 20 ltrs of oil and started to work the hydraulics before the engine went. was slow to respond but eventually got better then the engine went. thats when i noticed oil on top of the hyd motor.

 

[waynemags]

ok. ive decided to buy a longblock from wisconsin dealer in ontario. now i noticed that aft6er i put hyd oil in before thhis all happened, the started to be a good leak on top of the hyd motor that attaches to the wisconsin motor. looks to be thge main hyd motor. hydrp pump. im gonna start taking hoses off and look for filters. is there a possibility that i blew something or worse broke something? i added 20 ltrs of oil and started to work the hydraulics before the engine went. was slow to respond but eventually got better then the engine went. thats when i noticed oil on top of the hyd motor.

does anyone know if a 620 bobcat engine is the same size as the 720

 

[Miker67]

ok. ive decided to buy a longblock from wisconsin dealer in ontario. now i noticed that aft6er i put hyd oil in before thhis all happened, the started to be a good leak on top of the hyd motor that attaches to the wisconsin motor. looks to be thge main hyd motor. hydrp pump. im gonna start taking hoses off and look for filters. is there a possibility that i blew something or worse broke something? i added 20 ltrs of oil and started to work the hydraulics before the engine went. was slow to respond but eventually got better then the engine went. thats when i noticed oil on top of the hyd motor.

Unless you are sure something is wrong with the hydraulic pump, I wouldn't tear into it and I definately wouldn't replace anything else unless you had a smoking gun to look at. Maybe take it to a hyd shop and see if they can bench test it and if it checks out reassemble everything and start chasing the leak then. The old govt mantra of "if it ain't broke, fix it till it is" is not always good for the rest of us.

 

[OldMachinist]

Unless you are sure something is wrong with the hydraulic pump, I wouldn't tear into it and I definately wouldn't replace anything else unless you had a smoking gun to look at. Maybe take it to a hyd shop and see if they can bench test it and if it checks out reassemble everything and start chasing the leak then. The old govt mantra of "if it ain't broke, fix it till it is" is not always good for the rest of us.

Yes the 620 and 720 had the same engine

 

[waynemags]

Yes the 620 and 720 had the same engine

is there o-rings in there where the lines attach that may need replacing or started to leak?