Good stuff! Nothing like some classic American ingenuity. I might have to do a MM to my 7901 but I don't want it to be too loud as a lot of my cutting is done at my house with some neighbors somewhat close by.
Welcome to FHC Jutt! Stick around you will like this place! Muffler modded saws will definately put a smile on YOUR face and a scowl on your NEIGHBORS!
Cgraham1, saw coils are made of two basic components, the laminated "U" shaped fame and a plastic encased coil assembly. The coil assembly is then pressed onto the frame to be complete. With the Dolmar 7900 a lot of guys take the 272 coil portion that does not have rpm limiting electronics and press that portion onto the oem Dolmar laminated coil frame. The other option is to use the 272 coil and slot the mounting holes for proper alignment. The flywheel key must be ground off off the flywheel and then the flywheel re - indexed for proper ignition timing
Kev, I just use a 272 coil re time fanwheel. Plug wire has to be carefully routed as the lead on the coil is in a different location. The "Key" is cast into the fanwheel and needs to be carefully removed so the taper mates with the crankshaft.
Most if torqued correctly won't slip. I've had the 046 slip twice now with no key. I tightened it until I thought I was going to strip the crank so I hope it doesn't slip any more.
Guaranteed that you will crack the flywheel before you strip the crank ............... usually cracks appear at the keyway slot (if it has one), or along the flywheels thinnest axis (not where any ribs are). 1/2 of a drop of Loctite 640 and an overnight cure solve the keyless spin problems, while still allowing you to remove the flywheel if wanted.
Funny because I got a whole bunch of flap for suggesting the same thing on another forum - I guess that's why I hang out here... a bunch of folks with real world experience
Looks and sounds great! I herd it was a real good runner! I always wanted to play with a 7900...but never got around to it.
That is the new 7900 OEM top end with the decomp in the same place as the Solo. I was surprised by that myself. I have another new kit here I'll look at in a few minutes to see if that's the same. Exhaust stock is 107° with 25° of blowdown and intake is 80°
