Topic: 76 cb750F. To fix or to part?

[Burvis]

I failed to completely secure the master link on my 76 CB 750 F.  The chain came off at speed and now I have a neat little hole in the crankcase.  I'm conflicted about how to move forward.  I had put a fair amount of time and money into making it a daily rider, new tires, chain and sprckets, new battery.  Brakes are reworked with braided stainless lines, and I had put on superbike bars and reworked the rear fender - never liked the plastic at the back of a stock '76 F model. 

Still, the engine was pretty tired anyway with 40k miles, a noisy valve train, a clutch that squawks when engaging cold and some other age-related defecits.

I understand that cases can be repaired with epoxy?  Anyone done that?

I have heard nightmares about swapping engines out in these frames.  But I have found a dissassembled wiseco bore-job engine on CL for a reasonable amount...

Or should I part it out?  What would you do?  I'm hoping for some common sense here.  Am I blinded by love?  Is it time to cut my losses?

[xfactor]

I will buy your front caliper and rooter if you decide to part it out.



Croix

[BeSeeingYou]

I have heard that JB Weld works for this.  40 K is not that much and the issues you describe don't sound that serious.  Have the valves been properly adjusted.?

If you do part it out I would be interested in the muffler if it is in good solid shape.

[worlddrum13]

Ihad a warrior 350 fourwheeler that the chain broke and put a hole in the case. I used small piece of fiberglass and jb weld and it was good as new. I'm sure it would be similar with the cb,'s 

[Jerry Rxman Griffin aka MuthaF'er]

Swapping engines is NOT a problem. They all have the same mounts. The 77 and up F's and K's use a 630 chain so you'd need to convert your bike to 630 or the engine output shaft to 530. Conversion kits are made too.

[ofreen]

It would be a shame to part out a running bike.  Without seeing the hole, I'd say it can probably be fixed with JB Weld.

[gsgleason]

While I'd prefer you fix the hold with JB weld and keep a great bike going, parts for the F0 and F1 are exceedingly hard to come by, and I am in dire need of a fuel tank, handlebars, brake calipers, and I'm sure a few other things.

[Tennessee]

I'll keep a look out for an engine for you.  I think there is a complete 1976 SS up the road from us for sale.  Once I hear back from the guy i'll let you know mile/condition.

[Markcb750]

I have a complete engine that has significant fin damage so I am disassembling the motor & parting it out.

I want the clutch & head, jugs are useless, but the remaining case & transmission look fine.

If you want the cases PM me.

[Stev-o]

Either repair the case if it is a small hole or slap another motor in her.
How much do you have it it?

[Jerry Rxman Griffin aka MuthaF'er]

While I'd prefer you fix the hold with JB weld and keep a great bike going, parts for the F0 and F1 are exceedingly hard to come by, and I am in dire need of a fuel tank, handlebars, brake calipers, and I'm sure a few other things.

Aftermarket handlebars are available at Sudco. They list the same one twice and as fitting 69+. I had my doubts. Talked with the guy at Sudco and he assured me their bars are identical to the 76K. The ones for our F's are -341 bars. 74-76K & 75-76F. I matched them up when they came in. Perfect match. Other than Sudco the only other place I have found them are Yamiya in Japan.

Brake calipers on EBay or from a member perhaps. Of course they wouldn't be new and could be a crap shoot as to what you end up with.

Tank - good luck.

I've been watching EBay nightly for NOS parts for 4 years. That type of dedication is what it takes! I have almost enough to build a NOS bike. 

[Burvis]

Thanks for all the replies, seems I should try JB weld before throwing out the baby with the bathwater. 

GSgleason, I have the stock handlebars for this bike, and a rear caliper.  The caliper had a broken bleed valve, and I tried to drill it out.  I think I ruined it, but I'm happy to give it to you if you want to try and fix.  Make me an offer on the bars, and I'll throw in the caliper. I also have the stock airbox and turn signals, if anyone wants em.

My stock tank was rusted out, and I replaced with an older K tank, a 74 I think. Those tanks fit the mounts, but they are shorter, and I had to modify my seat mounts and move it forward about 2" to close the gap.  I think it looks cool that way.  Might be easier to find a K tank.

Tennessee, let me know what you find out.  I think I will continue to look into getting an engine to rebuild.  I have had this bike for 12 years, I guess I'm in for the long haul...

[vern401]

I have used J.B. Wield to fix small holes in blocks before. You will want to prep the area well. No oil on it and rough up an area around the hole to give it something to bite to. Gas, Oil, and brake fluid do not effect cured JB Wield. I have used it to patch Master cylendar Res. Timing covers on trucks. Dents in Gas tanks, ETC. Just like in painting the Prep work is the most important part. I used it to fix the carb on my 78 SOHC Super Sport. The carb that has the idle adjustment screw was broke when I got the bike. I used black electrical tape to give the inside and top shape lines. Roughed up the outer serface area that the epoxy was going to need to use. Once cured I removed the tape. It's working great and keeps the rain out. I did hafto make a different way to adjust the idle though.