My 81 G1 has a Problem figures

[ic746]

Well I need help from you pro's on here about the G1 engine. I should know this and I think I know what it needs here goes. I use my 81 G1 mainly for play and running around and I also use it to pull my 60 inch cut Swisher finish mower. Well after mowing today 2 acres I was climbing the hill on one of my 2 acres running about 5mph and it just started losing power. I had just recently put in new seals and they really helped a lot. Well I was on my last pull up the hill mowing and it just lost all power and shut off and a little smoke come out from underneath. It was hot, oh I also had all the plastic off the engine this winter and wire brushed and air blew out all that crap in there. I waited several minutes and it started right up but not enough power to pull. So I waiting 15 minutes it started up and ran good enough to get back to my garage. I pulled the plug put in the compression tester and with the engine hot it was only 85lbs. Do I need rings? And possible a bore out and bigger rings? Thanks fellows.
Calvin

[smallblock450sl]

Calvin, you don't need our help, you know what it is. G1's should have 120 lbs compression, 100 minimum (although 1982's (J17's) were low compression engines and should read 110 to 90 minimum). 2 way's to go..rebore and oversized piston and ring set and gaskets or a aftermarket top end assy, IE: cylinder/piston/piston pin/rings/gaskets,it would be standard bore. Really depends on costs of reboreing the stock cylinder and the price differance witch option you choose. I'm not a fan of aftermarket piston rings, but others may have a differant opinion. Lastly, I have not found the oversized set up will get you anymore power. Hope that helped some my freind. Let us know what you plan to do. Later Dave

[crash12888]

hey Calvin, Slow moving (low RPMs) plus the load of the mower probably got it way hot and siezed the rings. I would at least expect rings but you still should mic the bore.

[TheNewGuy]

Yep, check the cylinder size, see how bad it is first. You could swap out with your other engine.

[ic746]

Hi Crash and Ron, Crash I figured I got it too hot today and that is what it did. Its used to running full bore and this one is still stock and I got it running around 27mph with the GPS. So today after putting it through a lot of uphill pulling it just had to rest hahaa.

Ron I thought of the other engine but I was hoping to save it for my 82 G1 the Geep II just in case its engine let loose. I guess I will give it a try and tear it down tomorrow and Im sure its just the rings and old age because it still runs and runs fast I just got it to hot today. I do have another question though, Im sure being its 29 years old its time to re ring it and probably have it bored but have no clue on where to take the jug and the piston if needed to have that done. Will a regular car engine shop do that rebore?
Thanks my friends for all your help.;
Calvin

[TheNewGuy]

Originally Posted by ic746

Hi Crash and Ron, Crash I figured I got it too hot today and that is what it did. Its used to running full bore and this one is still stock and I got it running around 27mph with the GPS. So today after putting it through a lot of uphill pulling it just had to rest hahaa.

Ron I thought of the other engine but I was hoping to save it for my 82 G1 the Geep II just in case its engine let loose. I guess I will give it a try and tear it down tomorrow and Im sure its just the rings and old age because it still runs and runs fast I just got it to hot today. I do have another question though, Im sure being its 29 years old its time to re ring it and probably have it bored but have no clue on where to take the jug and the piston if needed to have that done. Will a regular car engine shop do that rebore?
Thanks my friends for all your help.;
Calvin

I would think a car engine shop could bore out the cylinder with no problem. They will just need the size to bore.

[crash12888]

Most prefer to have the piston on hand before they bore so they can double check sizes.

[Flintrock]

I.ve had luck with cycle shops too. Call around, decide if you need to re-bore or not. They can help you tell if it's out of spec on the roundness or size. If you over bore, get the piston first and take it with you. Per Crash, I think any decent shop will insist on having it.

[ic746]

Thanks fellows well I am up early getting ready to call the engine shops around here and see what happens. I'll also check at the cycle shops also FlintRock, sure wasn't looking forward to this but guess that is how it goes.
Calvin

[crash12888]

Originally Posted by ic746

Thanks fellows well I am up early getting ready to call the engine shops around here and see what happens. I'll also check at the cycle shops also FlintRock, sure wasn't looking forward to this but guess that is how it goes.
Calvin

10:06AM???????????????
Git er done!!