Engine re-build question

[pablotrini67]

Hello
I recently took on a 1979 CBX on which I am planning to do a frame-off restoration .The chassis was a roller but everything needs either re-building or replacing as the bike had sat outside & was exposed to the elements,there were a few missing items which I have been able to locate. The engine had been disassembled by the previous owner & came in boxes
My concern with re-building the motor is the project included a Forsetti 1147 cc big bore kit ,this engine is a very early motor SER #CB-1E-20022195
& has the straight cylinder head studs , which apparently were prone to breaking on the early engines ,not corrugated cylinder head studs ,The reason for wanting to re-bore is the cylinders 1 & 5 have a small area of scouring ,although I am no expert but just eye-balling the damaged cylinders I could probably get away with re-boring to 2nd over and stay away from the big bore .
Just wandering if this would be the best way to go and if it needs re-bore to 1147 cc does anyone have knowledge of the quality of the Forseti pistons.
Thx ,Paul

[steve murdoch icoa #5322]

Welcome to the site, Paul.
There are quite a few CBX owners in your area and on this site so help might be nearby.
Quick search didn't turn up anything about the Forseti pistons.

[daves79x]

The serial number you posted would be for a very late '79. Did you add an extra digit? A smooth-stud engine would be under approx. 3200.

Dave

[pablotrini67]

Ooops, You are correct the SER # is in fact CB-1E-2002195 . 3

[pablotrini67]

I have been in touch with another Calgary member who early this year did an amazing job on his 1979 CBX restoration & had it all documented on this forum , I got to see the bike in person and it looked like it had just been ridden out of the showroom in 1979 ,he has been very helpfull with lot's of photos of the engine re-build and restoration process & also links to websites with lot's of info.

[CBX-tras]

You're in for a HUGE learning curve if you didn't take apart the CBX puzzle that you bought.

Take your time, ask questions, get and read the factory shop manual, inspect/measure everything for wear. When in doubt, throw it out.

Obvious to me that the fellow that took it apart didn't understand these bikes either since he marked the coils for their firing order. That's a novice move.

Before you install the cams, just know that there was a misprint in some of the FSMs. The #1 lobes need to be opposite of the #6 lobes.

Don't be afraid to tag-in here if you have questions. Several of us can identify every part by sight.

About the compromised cylinders, (others may disagree) if you can find a couple of first over pistons/rings, just repair those 2 bores and re-ring the others after a slight ball honing to knock off the shine. But, find a machine shop in your area that does this type of work to get a professional opinion.
Fresh cylinders sets can be bought too from individuals if you want to stay 100% stock.

Best of luck,

[wyly]

Hey Paul another CBX from Fred's collection. If you have engine rebuild issues that you don't feel confident taking on do as I advised Devon, bring it to Vass Performance in Carstairs. Willie's technical expertise is 2nd to none but as he's very busy in summer hours with super bike racing so winter is the time to do it. I'll be bringing him my GS1150efe for a overbore/re sleeve this winter as well.

I don't have any experience with the Forsetti 1147 kit, I have a Wiseco overbore. Willie would be your best guide for aftermarket product knowledge.

[pablotrini67]

Yes another CBX from Fred's collection ,he is definitely thinning the herd ,this one sat outside the garage and was leaning against the tent where he has a number of bikes stored. A number of years ago it was a running bike but was burning alot of oil & he had pulled and stripped the motor ,two of the cylinders had slight scouring & he had bought the Forseti big bore kit to re-build the engine but probably got busy with all his other projects and never got around to do the re-build. Looking at the cylinder I think maybe just doing a 2nd over would be ok ,all the other cylinders the original honing marks are still visible & the original pistons are in good shape ,just want to keep the motor close to stock ,but an expert will make that decision .The speedo ,if correct the bike only had 42,000 kms .Have contacted Devin and he has been a great help.
I have been told about Willie Vass so will definitely contact him ,probably won't happen untill next year as just want to get the chassis re-built first then tackle the motor , just wandering is he a mechanic on one of the WSBK teams.

[wyly]

Your 79 has spent a number of years under that plastic tarp I thought it was just a parts bike never thought of it as a project. I've been asked if I wanted the '82 on his table but I have my '84 GS1150efe taking up my time for the next couple years.

I know Willie has spent time on the world circuit I don't know with what teams, Buell racing and crew chief for the current CSBK champion. Before covid shut things down he was also busy during the USA racing season. It's amazing watching him work, so quick and efficient.

[pablotrini67]

Making progress on the 79 CBX project , up on wheels ,had the frame powder coated ,re-built the rear shocks ,actually just cleaned off the rust on a
bench grinder with a wire wheel & replaced the springs with progressive springs , look like new ,replaced the wire harness ,re-built the front shocks ,serviced the speedo & tachometer new bulbs etc,
I re-built the front & rear brakes ,the front brakes as per usual gave a real headache to bleed and felt mushy ,as per the advice on this forum went out & bought a vacuum bleeder ,job done & they now feel like moto=gp front brake .
The rear brake master cylinder was completely frozen , had it soaking in release-all for a few days but still would not budge ,I drilled a hole in the top of the piston and used an easy-out ,the piston snapped about half-way , still would not budge ,lucky I have a friend who has a small milling machine where the cylinder was held firmly in place so that the the milling bit does not contact the cylinder bore ,job done master cylinder saved.
From the attached picture of the master cylinder there are two holes in the fluid inlet ,one is open to the cylinder bore and the other is not ,looking down in the bore I can see the one hole ,just wandering if both should be open to the cylinder bore .
The bike came with a spark-unit ,it had the black stuff oozing out , have read that it might still be good ,is there some way of testing this unit to see if it still is good.

Thx ,Trini 67

[tevan]

As far as your master cylinder. Both holes should be open. There is one large hole and a small hole. Take a strand of your wire brush and push it thru the small port. Do not enlarge the hole any bigger then the strand of wire brush. It is a small but you need it open.

[pablotrini67]

ok , that's what I was thinking ,the larger hole is open ,just definitely plugged solid and couldn't see any hole on the inside ,will make sure it's open .
Thx ,Trini67

[NobleHops]

Good looking roller, your project shows great promise!

[pablotrini67]

Making progress on the 1979 CBX project ,got back all the painted parts & thx to Craig "Bentley" Cooksley of Bentley's motosicle pain tin in Crestomere Alb who did a quality job on time and reasonable price .Have decided to go with the Forseti 1147 big bore kit which came with the project ,the cylinder and rods etc are @ Willie Vass of Vass performance cycle in Carstairs Alb. ,Willie was highly recomended by many people.
I stripped down the head ,removed all the valves ,it had been re-built by the last owner and everything was in order and the valve seats and valves which had been slightly lapped in looked good with new valve stem seals in place ,the head got a good scrubbing and blasting @ the local car wash and has been re-built .My question is I have the head sitting on a workbench with the cams resting in the head ,would it be possible to bolt the cams in place and do the valves in this state as am sure some of the shims will need replacing.photo attached
Also I had opened the starter button not knowing it was spring loaded and stuff went flying ,I was able to find the small spring & two small brass contact which sit on top of the small spring ,just wandering if anything is missing,photo attached.
I have the transmission sitting in the lower case , the cases sit in a home made engine stand AKA "MECHAZILLA" ,yes it,s able to rotate and can lower the lower case onto the the upper case , I was wandering when placing the transmission into the case is there anything special that needs to be done to the transmission like making sure the moving gears which are moved by the selector fork are able to engage the corresponding gear ,the locator pins for the small bearing are in place as well as the 1/2 ring for the bigger bearings .
Thx ,Trini 67

[pablotrini67]

Good pic of Mechazilla