I'm tearing my 660 down to build a 719 stroker.
Did start to wonder why I was doing this as the quad had been going great, but figured has been hammered the last 12 months, probably should
Motor on bench, cam cover off, undo first cam bolt, turn it over to get the other cam bolt & the Decomp Weight Retainer is half missing!
Found the missing pieces & some metal filings in the bottom of the sump!
Close call, my motor is NOT going to have a decomp as a result of this!
It just ain't worth it!
Yikes, good timing phil.
I'd seek out bigdaddy660r's kit, you get to keep the decomp so that it actually starts when you want it to and you don't need to go industrial grade on your wiring and batteries but also prevents the issue of the keepers failing to keep.
I figure on X4 cam, so the big overlap drops effective compression when cranking
one of these batteries: http://www.antigravitybatteries.com/faq.html
& am going thru ther whole wiring loom anyway............
I will leave the internals in the cam, but put a keeper plate on to hold it in the "locked out" position so there is no decompression.
I can always add the bigdaddy660r kit later if I think it's a problem.
If you're not going to use the decomp then remove the keepers, pins and weights from the cam gear and just tack weld the decomp insert into the face of the cam.
I ran my 660 with an 11:1 and an x4 for a couple years, unless it was hot it didn't like to start without my manual decomp. Make sure that battery has extra CCA's, I believe standard is 140, something in the neighborhood of 200+ would be preferred as that is the power of the grizzly battery.
I have tried to get hold of bogdaddy660r, but no joy.
Hence wanting to ditch the decomp.
Guess the other way to look at it was that the stock parts are now 8 years old, so buying new stock parts should last another 2-3 even with the extra revs & power the motor will have.
Decisions, decisions..............
Dang, good catch phil. Good thing winters upon you now
Oh DAMN ! REAL CLOSE CALL !!!!
I ran my 719 w/ a stock battery and no decomp with a stage 3 cam. I ran the decomp with the X4 for a short period, but that's when my decomp came apart :aaron: If you haven't gotten your cam yet - consider the stage 3 Hotcam. It's less expensive, and almost identical to an X4 on the dyno FYI...
Thanks Seg, got the X4 at the right price, so all good :)
Just got an anti-gravity battery, figured the extra cranking amperage would be a good thing on the 719 without the decomp.
Shall see how it goes.
Do have a spare truck battery.................
Hell yeah, can't complain there !! lookin forward to hearing the review 8)
I finally has me bits!
X4 Cam
+4 HotRods crank
102mm piston
bored cyl to suit
gearbox bearings (one was a little rumbly, so replacing the set)
Gaskets
39mm FCR's
HV ported head
Now all I need is time.
Have stripped the frame as well & getting re-painted in 2-pak epoxy.
Will take a few pics as motor goes back together, & bike gets re-assembled :-)
Sounds like a nice setup, can't wait to see it come together.
good luck Phil! :thumbs: