4000 mile 670?

[magnet]

lookin for sugestions my 670x is goin to hit around 400 to 4250 mile this spring. never been touched still stock. Should i rebuild over the summer, or ride till she pops. Don't want to be down mid season though. Miles are probably 50/50 mountain and trail as the last guy rode revy every second weekend. Would it be worth while to go to a 740 at the time of rebuild?

 

[boondockin]

lookin for sugestions my 670x is goin to hit around 400 to 4250 mile this spring. never been touched still stock. Should i rebuild over the summer, or ride till she pops. Don't want to be down mid season though. Miles are probably 50/50 mountain and trail as the last guy rode revy every second weekend. Would it be worth while to go to a 740 at the time of rebuild?

does it have the power you'd like? thatd be the turning point for the 740, if it has enough id rebuild the top end, when its apart inspect the bottom end, if she's good put it back together and go for another 4000 miles:d

 

[Modman]

does it have the power you'd like? thatd be the turning point for the 740, if it has enough id rebuild the top end, when its apart inspect the bottom end, if she's good put it back together and go for another 4000 miles:d

Yep ^^^^^ what he said. 740's require case machining to fit the sleeves. All depends on how much power and money you want to put into it.

I'd just re-build it this summer, not too much of a season left now and then it will be preventative maintenance for next year

 

[magnet]

Is there ever such a thing as enough power? Thats kinda what i was thinking though as well just freshen up a giver.:d

 

[SLEDBUNNYRACING]

My 670 went at 5800.
I had the crank trued at the same time but it was actually ok.
If your going back to stock I would do the rebuild this summer, if it goeswhile riding the damage might be more that you want to repair.

 

[Deano670]

Good chance you'll spend almost as much as rebuilding what you have as apposed to going 740. Just some food for thought

 

[my mod]

Just do rebuild, rings and pistons might be all you need. If you go to a 740 kit you will have carb issues, clutching and other stuff to dial in and a bunch of cash to spend
If it runs good now, just freshen it up and enjoy, it will run another 4000 miles

 

[Modman]

Is there ever such a thing as enough power? Thats kinda what i was thinking though as well just freshen up a giver.:d

Yes there is too much power!!!! Maybe not for the rider but other parts of the drivetrain etc maybe won't like the added power as much as the operator!! LOL I say if its a 11 yr old sled no point in getting too crazy with it, just ride it and save the money for something newer when you can afford it.

 

[Firefly]

My 96 Formula SS 670 blew at 4300 miles about a month into the 2001-02 sled season. Did a real nasty job on the whole engine crank and all! I was kicking my butt that I didn't take the time in the summer to freshen it up.

 

[my mod]

the 670 was pretty much a bullet proof engine but it is old technology by todays standards. Freshen it up for under $400.00 and you have an old dependable sled. It would be cheaper to by something newer if you want more out of your sled. Not sure how much you already have done to this thing, porting, pipes or original clutching, you can make a few minor changes to get a little more.

 

[Scotty]

My 670 went at 5800.
I had the crank trued at the same time but it was actually ok.
If your going back to stock I would do the rebuild this summer, if it goeswhile riding the damage might be more that you want to repair.

While on the road to our ride in January with my brother, I mentioned that we should do a top end on his machine as it had 5200 miles on it, about 8500 km. He agreed. too late though, that weekend he lost a ring and it took out the cylinder wall as well. He still says I cursed it??

As SLB says... the damage that will occur when it fails might be too much as the sled itself is only worth, maybe, 2500.00 - 3000.00??

You should be able to do a topend for 380.00 bucks on that sled... thats just parts.

I would do it this summer for sure, its a simple job just make sure your ring gap is correct and the rings are the right side up

 

[Deano670]

While on the road to our ride in January with my brother, I mentioned that we should do a top end on his machine as it had 5200 miles on it, about 8500 km. He agreed. too late though, that weekend he lost a ring and it took out the cylinder wall as well. He still says I cursed it??

As SLB says... the damage that will occur when it fails might be too much as the sled itself is only worth, maybe, 2500.00 - 3000.00??

You should be able to do a topend for 380.00 bucks on that sled... thats just parts.

I would do it this summer for sure, its a simple job just make sure your ring gap is correct and the rings are the right side up

The 740 is a great deal, roughly 2400.00cdn stock carbs and pipe, reliable substantiel hp gains over the 670, really pull the cord and ride all day long. Again just food for thought.

 

[dooryder]

deano does have 670 in his name, so i think he knows a bit about the 670s

 

[my mod]

deano does have 670 in his name, so i think he knows a bit about the 670s

You are absolutly right! How could anyone argue with that logic!!:d