Tokke

Hi

My Honda Superhawk(firestorm) has got low compression(4 bar) and the ratio is supposed to be 9.4:1.Can anybody tel me or give me advise what it could be ?
The Bike doesn’t smoke or leak oil and has a flat spot from 6000rpm's to 9000rpm's.

nykuryu

so you have a reading of about 56 lbs (for us silly americans). first are these readings on a warm motor? yes, put some oil in there and redo test. No, warm up bike first. if you add oil and you get higher readings your pistons rings are probably to blame. if your readings dont really change you may have bad valve seating.

7moore7

Front cylinder? Rear? Both? Like nykuryu said, add a few drops of oil into your spark plug hole and test compression again. If the rings are bad, the oil will temporarily seal them and the compression will go up. If the oil test doesn't change the compression, then it's the valves or possibly a bad gasket.

Tokke

The valves has been tested and it's fine they say.

nykuryu

how were they "tested"?only way to really test em is with a compression test or a leakdown test

Tokke

They did a compression test and it is fine.

nothing

It's obviously not fine if your compression is that low! LOL mine were nearly 3x as much.

nykuryu

ya your compression reading should be rockin around 169 lbs i think or around 12 bar for you.