What should 87 Spree compression be?

[GaryMpls]

I can't get my 87 Spree to start. I am going to test the compression with a compression gauge. What should a normal reading be for the compression?

[edjo]

Anything over 100 is good. Anything lower than 100 and the rings may be on the way out. Anything 50 and under it probably won't even start.

[Kenny_McCormic]

Alot of compression testers will read low on ver small engines so dont expect 120 or anytthing like that. A quick way to see if it is bad compression is too put a capful or two of oil into the sparkplug hole, kick the engine over a few times and replace the sparkplug. If it starts or pops over and trys to run then you have bad compression. This trick will sometimes "restore" compression permanatly if it was soft seized and the rings were stuck to the piston.

[edjo]

He already did that in another post and it didn't start. Thats why I suggested a comp. test. When I put a gauge on mine it pumps right up, its just a basic $60 set from Sears.

[GaryMpls]

Thanks guys.
I will get a compression tester and see what I've got for compression.

[burnt_toast]

Alot of compression testers will read low on ver small engines so dont expect 120 or anytthing like that. A quick way to see if it is bad compression is too put a capful or two of oil into the sparkplug hole, kick the engine over a few times and replace the sparkplug. If it starts or pops over and trys to run then you have bad compression. This trick will sometimes "restore" compression permanatly if it was soft seized and the rings were stuck to the piston.

However this is very good advice, helped me seat some rings in a new engine install that had gone dry.

[Kenny_McCormic]

Yesterday i fixed a seized leafblower using this trick and a can of PB Blaster (WD40 on steroids)

[GaryMpls]

I put a compression tester on it and had 55psi. I removed the head and cylinder and found that the rings were stuck. Cylinder looks pretty good and has no scratches or gouges. Keep in mind that this machine had not been started in about 15 years.

I've got the piston and rings soaking in PB Blaster (similar to WD-40). I hope this frees up the rings. If it doesn't, does anyone have any other ideas to free them up?

[Dac]

bust them off and buy a new set. there about 30$ at a honda power sports dealer. if there baked on there there's a 90% chance there thinner then they should be. putting on a new set will give you better compression and theres let chance of it breaking once you get it running. i learned that reusing rings is not the way to go. I reused a set that was baked on and when they broke it fried my cylinder.

[Kenny_McCormic]

Yea it would probably be best to get new rings now that its gutted and all.

[DENMANSHAFFER]

I have 2 86 Sprees and have tested compression with a small engine test set from J C Whitney (Ithink) and got readings of only around 55 on both units. Both start instantly and run great. I concur with earlier post that there may be a lot of difference in readings on different size engines and with different equipment.
You might try heating your piston a little bit to try and free the rings. The aluminum will expand more than the cast iron rings and you might be able to pop them loose. I have had to do this to get rings back onto a piston when reassembling. doesn't seem to hurt anything.

I have never even pulled the head or cylinder off either scooter. Once I got them running, I just kept on going.

[Dac]

bust them off and buy a new set. there about 30$ at a honda power sports dealer. if there baked on there there's a 90% chance there thinner then they should be. putting on a new set will give you better compression and theres let chance of it breaking once you get it running. i learned that reusing rings is not the way to go. I reused a set that was baked on and when they broke it fried my cylinder.

i still stick by this.