1986 Spree with low compression and will not start

[Gloworm5]

I am rebuilding a 1986 Spree that sat up for 20 years with oil and gas in it. It only has 240 miles on the odometer as many may remember from other postings.

I broke things down. I replaced the head and cylinder gaskets as well as the rings. The cylinder wall was smooth with no scratches. Before assembly, I coated everything well with 2-cycle oil. I tightened the head bolts to 8-10 ft/lbs. It reads only 65 psi compression. I think that is about half what it should be correct? Before I tear the motor down again, is there anything that I could have missed. It is odd that it is almost exactly half the compression I think it should have...maybe it is just a coincidence.

I am tired and very frustrated at this point and it is not like me to quit but I am thinking that way. Please give me some suggestions! I really don't want to tear the motor back down unless that is the only suggestion at this point.

Thanks for your help!

[odinxxix]

you prolly should have went ahead and honed the cylinder. are you positive that the base gasket didnt get cut when you tightened everything down? your compression should be min 114 psi.

[Clivester]

Did you hone the bore before fitting the new rings?

Do a compression test, then add a teaspoon of 2-stroke oil through the spark plug hole. Retest the compression. If it goes up you probably have a poor piston ring seal. Try to re-hone the bore if not done before.

If the compression reading does not increase with oil check the reeds to make sure there is no leakage there.

[Rowbear]

try a different compression gage

[Gloworm5]

you prolly should have went ahead and honed the cylinder. are you positive that the base gasket didnt get cut when you tightened everything down? your compression should be min 114 psi.

You are right, I wish now that I had honed the cylinder down while I had the chance. I did not have the right hone so I skipped that step since the mileage was so low. Bad step on my part.

[Gloworm5]

Did you hone the bore before fitting the new rings?

Do a compression test, then add a teaspoon of 2-stroke oil through the spark plug hole. Retest the compression. If it goes up you probably have a poor piston ring seal. Try to re-hone the bore if not done before.

If the compression reading does not increase with oil check the reeds to make sure there is no leakage there.

A very good suggestion...I will do that before I tear it back down. I had not thought of this step.

[Gloworm5]

try a different compression gage

That's a possibility...I just don't own but one and I don't know anyone with one.

[Bear45-70]

try a different compression gage

That's a possibility...I just don't own but one and I don't know anyone with one.

Try it in a known good engine, if it reads close to what it should then you should be good with the gage.

There is no way on this planet that bad reeds would drop your compression by 50 PSI, even if they were not there. New rings always require an hone job, regardless of time on the motor.

[Gloworm5]

Well, folks...trajedy hit. I honed the cylinder. I reassembled the cylinder, piston, rings, and gaskets. I torqued the head bolts to spec. I took a compression check and it showed zero psi. compression. I looked everything over very well and could not find anything wrong. So, I thought I would take one more round on the head bolts to make sure I had not missed one. On the third bolt it snapped off. Tragedy had struck!

Where did I go wrong? Should I have replaced the rings and the gaskets again? I did not reassemble the engine all the way. I assembled just enough to take a good reading. The way I saw it as long as I had the cylinder, piston, rings, and gaskets assembled I should see a good reading. Is this where I made my mistake. This is my first engine rebuild so I am learning a lot as I go.

After I manage to get the head bolt out and replaced...what would be everyone's suggestions for trying it again? I think I have one more try left in me before I give it up.

Thanks everyone!

[Bear45-70]

Well, folks...trajedy hit. I honed the cylinder. I reassembled the cylinder, piston, rings, and gaskets. I torqued the head bolts to spec. I took a compression check and it showed zero psi. compression. I looked everything over very well and could not find anything wrong. So, I thought I would take one more round on the head bolts to make sure I had not missed one. On the third bolt it snapped off. Tragedy had struck!

Where did I go wrong? Should I have replaced the rings and the gaskets again? I did not reassemble the engine all the way. I assembled just enough to take a good reading. The way I saw it as long as I had the cylinder, piston, rings, and gaskets assembled I should see a good reading. Is this where I made my mistake. This is my first engine rebuild so I am learning a lot as I go.

After I manage to get the head bolt out and replaced...what would be everyone's suggestions for trying it again? I think I have one more try left in me before I give it up.

Thanks everyone!

They give a torque spec for a reason. They also make torque wrenches so this does not happen.

[Wheelman-111]

Greetings:

Glad you got that bolt out. Even a piston with a hole in it will show greater than Zero compression . I'd try another gauge before you take anything else apart. Bear's correct, adding headbolt torque wasn't a good idea. Now you know.