connecting rod bearing, crank end...

[CamaroJeff™]

well ive tried the search function, but it dosent seem to want to work for me...

long story short ive got a connecting rod bearing on the crank end thats starting to make some noise on me. ive got another bottom end that seems to be in good shape (its nice and tight) but 2 of the studs that bolt the cylinder on are broke flush with the case.

i would use this bottom end, but ive already broke a couple of rather expensive drill bits trying to get the studs out. im going to try to weld a nut to the broken studs when i get the chance, but im looking for alternatives at this point.

im wondering if its necessary to take the bottom end to a machine shop to have the bearing/rod/crank replaced? the bottom end im using does have a "hot rods" connecting rod and id like to keep using it providing its not wasted.

if it were at all possible i have no problems with putting this other rod/crank combo in the good (dosent have broken studs) case, but is this something i can do at home? ive got plenty of tools but from what i gather from the service manual the 2 piece crank is a pressed fit...

any help on this is greatly appreciated

 

[Wildcard2]

I would just take the broken studs to a machine shop and have them extract them. I would not weld there you will end up with weld spatters on the aluminum. and you can replace the studs its not that expencive

 

[CamaroJeff™]

dude, i woudnt be welding with flux core or arc, mig all the way. any spatter is easily removed.

my main question is what does it take to seperate the case and the crank?

 

[blaster99]

a BFH AND BFW and patients

 

[fmxr47]

splitting the cases is not hard but if you are i would buy your self a whole engine gasket kit and go to town and replace any wear items, any time u pull a crank or any shaft it is recommended to replace the seal for it but some times you can re use them but on a 2-stroke i would replace the crank seals while your in there

 

[FLOTEK]

take it to a machine shop ,your going to end up with a ruined set of cases and a ruined crank

 

[Kennedy_Power]

The machine shop option is the best. I would recommend a vertical mill like a Bridgeport. Use a end mill to square the broken stud before using a center drill. Then drill them out and use time serts to replace the threads on 4 corners. It’s a pretty simple procedure using a mill. I have also been successful using a TIG welder to weld a piece a material to the stud to turn it out. If you go the welder rout ,use good penetrating oil like Kroil.

 

[110octane]

Which studs are you referring too? Really I wouldn’t call them studs if they ever had some sort of head on them ie, screw head or bolt. The only "true studs" I can think of on a blaster are the cylinder 2 case studs and these are threaded on both sides.

This can actually be done at home, if your very carefull. Use a center punch to create a divet in the screw, spray the area down with WD-40 or similar lubericant, then go in with a small piolet drill bit followed by a larger bit then your screw extractor (extract in reverse drill obviously)

Splitting the cases is not difficult with the right tools. A Case splitter can be found at RMATV, Tusk I think makes the one I bought good quality splitter that will last a long time. You can do it without a case splitter but I would not recommend it as sometimes it gets difficult and you could crack the case when tapping it to loosen up the bond. The splitter is like $40. or something.