1978 gs1000E BB kit

[r6qc]

My 78 gs I picked up for $1500, the tank, side and tail pieces are in fantastic shape but the compression was down
So new tires, brakes, head/swing arm bearings,fork springs and new 10w , think I will get a fork brace from "fast from the past" $95
I did a quick ball hone(may have been the issue)and re ringed it($147) and the rings never did seat properly so after seeing a full big bore kit for $140 I pulled it down again, there is a small amount of taper in the barrels
The bore goes from 70mm to 73.5 mm , the pistons look very different from the Wiesco kit I used on the XS1100, very little dome , curious to see what the compression will be, they look identical to the stock pistons I pulled out
I did a hand lap job on the valves....really didn't need but #2 exhaust stem was wet so all new valve guide seals, complete gasket set from "Parts n More for $95, carb kits from the same supplier

The BB kit is enroute from the land of the rising sun

R6

 

[steve murdoch]

R6, i have to ask...what brand is the BB kit?

 

[posplayr]

R6, i have to ask...what is a BB kit.

BB-Big Bore

 

[Nessism]

Parts-n-More gaskets are Athena brand. Very bad quality base gaskets - the green one. Too soft to take the head clamp load. At minimum, get an OEM base gasket.

Photos below shows how an Athena base gasket extruded out of position. Not good.

 

[posplayr]

Parts-n-More gaskets are Athena brand. Very bad quality base gaskets - the green one. Too soft to take the head clamp load. At minimum, get an OEM base gasket.

Photos below shows how an Athena base gasket extruded out of position. Not good.

Looks good in the package but that is about it. I wonder how they justify keeping that on the market?

 

[steve murdoch]

BB-Big Bore

Hence the operator error. lol.
What i really meant to ask was what brand of BB was he waiting on.

 

[Nessism]

No name ebay set I suspect. 73.5mm pistons result in really thin liners after boring. Cheap enough though.

 

[posplayr]

Hence the operator error. lol.
What i really meant to ask was what brand of BB was he waiting on.

Crap, I'm thinking how did I miss that. :-\\\

I'm getting where I have to triple check what I post and then re edit about 5 times ...

maybe this BB

http://www.thegsresources.com/_forum/showpost.php?p=1789856&postcount=2

 

[r6qc]

The "BB" is for big bore kit
I am going to reconsider using the Athena base gasket after looking at the picture
Has anyone out there had any experience with the big bore kit from Japan thru Cruzinimage_co ?

 

[r6qc]

I did the same project last year on a XS1100 but used the Weisco kit, the bore was thin after it was honed out, isued the athena kit from "Parts n More"........now iam concerned with the base gasket, have put 2000 miles on the motor without and issue, had to put new springs and friction plates in the clutch....yee ha love the power
My friend owns the biggest engine rebuild shop in the lower mainland and he put the barrels on a computer honong machine set the final diameter and it honed down to it with the specified piston/bore clearance, will do the same with the GS barrels

R6

 

[TeamDar]

73.5 mm bore in a stock GS1000 cylinder is not a problem. I own two GS1000's with the Wiseco 73.5mm BB kit and have had no problems whatsoever. Wiseco would not recommend "cylinder boring only" for these kits if it was a problem. If you are really worried about it, find yourself a GS1100 shaft drive cylinder and you only need to bore it 1.5mm over for your kit. Check your deck height with the 1100 block it may need a little shaved off to get the pistons to the top of the cylinder. Dar

 

[r6qc]

I have no worries about the thickness of the bore, I may put in a oil cooler for looks as well as a bit of extra protection
It will be interesting to see the relative quality of te 2 different kits
I know the Wiseco will have higher compression hence more power but I just want a bike with a clean straight bore I have no worries about
With the closer to stock compression I wonder if it is worth going to a stage 3 set up again for looks as well as just something to do , a very cool hobby to be sure

R6