Volfy: great tip about the bolts type. Around here nobody could tell what kind they are..so imagine how hard is to me have my ryobis running at acceptable rates.

Mikenlapaz and JBfoster, thanks for the answers.
Now I have to get at least 16 socket head ( allen) Nš 10- 24TPI to add a engine mount at the rear of each engine.

In the case I could not find the bolts here around...where can I get them??
Thanks
Tato