Blew up the 670 today............

[Bogger]

Well......This is what we found....

Burnt piston, Jugs are good, Head needs to be cleaned up and a gasket kit, Lucked out on this one gonna be a $250 fix and about 90 ,inutes of re-assembly.

Brother inlaw was cool, Plio and I did all the wrenching under a close eye, same will go for re-assembly.

Counted all 28 pins from the bearing, nothing into the bottom end....:d

 

[posnick]

dont forget to hone the jugs out. are you replacing pistons on both sides? new gaskets? dont cheap out by trying to reuse the old ones

 

[Bogger]

dont forget to hone the jugs out. are you replacing pistons on both sides? new gaskets? dont cheap out by trying to reuse the old ones

Honing yes, having that done tomorow... Only replacing the one piston, after close examination there is no need to replace the other, it is mint.
Gasket kit, bearings ect.....

Oh you mean chep out by re-using gaskets..... Not a chance will be all new....

 

[s/b tech]

don't forget to put new rings on the piston that you are reusing

 

[mach123]

So what was the cause of this,

 

[Bogger]

So what was the cause of this,

not sure.... Bought the sled last year with 2600km on it, put 1000km on it and I'd noticed over the past week or so that it was smoking more when cold, finally quit on me while on the lake....I don't know what causes this chit to happen, I'm just glad it happened now and not on day #1 of my Yellowstone trip......

 

[rknight111]

Mabie going across a lake, wide open throttle for too long, and she got hot.

 

[mxz sledhead]

just rebuilt my 800 this fall bought the tools to do the job cost about $90
bearing sleeve and e clip installer it made job huge easier

 

[overkill131313]

I think you might want to go through the carbs...well at least the mag one. jets could have got gumed up over summer and leaned her down. at least check what is in it for jets! does it have the compesator on it for alt? nothing for temp right! just my 2 cents!

 

[magnet]

that lake sucks. thats where i blew mine up last weekend. blew a belt at about 90mph grabbed speedo cable and engine was so hungry it ate both of them, cable and belt, right through the crank seal. doh!!!!!!!!.

 

[Bogger]

I think you might want to go through the carbs...well at least the mag one. jets could have got gumed up over summer and leaned her down. at least check what is in it for jets! does it have the compesator on it for alt? nothing for temp right! just my 2 cents!

No jets because it's a DPM machine, we will go over the whole thing while it's down, I want to change out the chaincase oil as well but need to get a shop manual first because I've never had a chaincase with reverse apart and want to make sure I do everything right.....A side note to all this is that I am mechanically retarded and have ZERO experience with motors so I'm learning as I go.

that lake sucks. thats where i blew mine up last weekend. blew a belt at about 90mph grabbed speedo cable and engine was so hungry it ate both of them, cable and belt, right through the crank seal. doh!!!!!!!!.

That sucks, given what could have been I'm quite lucky. A piston, rings, gaskets and bearings is minor compared to what could have been. Buddy of mine has everything i need minus the caged needle bearings sitting in his shop, and is going to hone the jugs for me.

One question I do have is...... Once I get it back together I have to treat it as new with a break-in period right? when I do this, should I run the first tank with mixed fuel (50:1) for the extra lubrication? I've heard guys on here talking about using extra oil for their first tank.

 

[Bogger]

just rebuilt my 800 this fall bought the tools to do the job cost about $90
bearing sleeve and e clip installer it made job huge easier

What are these things you speak of?????? I know the old sleave through the piston was a c&nt to get out (old sleave and hammer). What is an e-clip installer??????

 

[femme.fatale.]

Bogger when are you going to Yellowstone?

 

[Bogger]

Bogger when are you going to Yellowstone?

February 25 thru 28th............

 

[femme.fatale.]

February 25 thru 28th............

Whens Terry going?

 

[Bogger]

Whens Terry going?

I've been trying to convince him to come....... It'll be a good time.

 

[femme.fatale.]

I've been trying to convince him to come....... It'll be a good time.

He's already got a trip on the go- down there in Feb. I thought you guys might have flanged something up??

 

[Modman]

What are these things you speak of?????? I know the old sleave through the piston was a c&nt to get out (old sleave and hammer). What is an e-clip installer??????

Get a piston pin puller for the next time, it will make life a lot easier and won't leave you bashing on the rod bearings.

"C" clip installer is what I think they are referring to - this is the "C" clip at the end of the piston pin. The tool is kind of a taper thing, hard to describe, works OK IMO, but after building race motors with double spiroloc pin retainers, the little C clips are easy.

 

[Bogger]

i seem to remember when i did the top end on my 98 I changed the bearings to a caged type....actually they came with the kit. if you need anything bogger, just ask

No Caged bearings.... I was told at martin that can't get caged forthe 99 670x

If you need assistance with the cage part I have done it numerous times - can help.

If I need help I'll call...... (Ric gave me your #.....Bwahahahahahahahah)

Watch if it has cageless needle bearings on the wrist pin. I know there are 28 needles on my rev, not sure if there all the same. You do not want to drop any down in to the crank case. Good luck and keep us posted.

Counted all 28 pins, had the bottom end stuffed with rags to prevent anything getting in... thanks guys....

Tech at martin says I might need a new head.... or have mine machined, I'll know more tomorow, my buddy's got a crate of parts for these things so he might have a head. I picked up the bearing, retainer clips and gasket for below the jugs.

Here's a couple close ups of the piston

 

[Bogger]

Close ups of the head.......