Topic: 76 cb750k parts interchangeable with 78 cb750k parts

[Dime]

My buddy that I am getting the complete 78 750k off of  has a 76 750k complete minus the frame as well.

We are talking about working a deal for both. I am mostly interested in the 76 engine, carbs and air box as a possible swap into the 78 frame.

The reason I am interested in this is so I would have the ability to completely rebuild the 76 engine with the cruzinimage big bore kit over time but still have a running bike in the mean time.

I know one difference between the two engines is the spacing on the sprocket for the final drive. Is that easily overcome?

What other issues would I run into with the 76 engine in the 78 frame?

The deal for both seems too good to pass up.

Thank you in advance

[Dime]

Is it possible to put an 78 output shaft in the 76 cases? If I do a full rebuild on the 76 engine I just thought that might be a possibility

[newday777]

Is it possible to put an 78 output shaft in the 76 cases? If I do a full rebuild on the 76 engine I just thought that might be a possibility

Only by splitting the cases

[Dime]

Is it possible to put an 78 output shaft in the 76 cases? If I do a full rebuild on the 76 engine I just thought that might be a possibility

Only by splitting the cases

That would be the plan for the 76 engine anyway. Take my time and do a full rebuild on it. Wouldn't be in any rush. Do the 823cc cruzinimage kit, ported head and any other reliability upgrades needed.

[Stev-o]

I know one difference between the two engines is the spacing on the sprocket for the final drive. Is that easily overcome?

Yes, I believe so.

I did the opposite, K8 motor in an earlier frame, no problem.  I used a different rear sprocket carrier so the chain would align properly.  The K8's used a larger chain but again, no issue.

[Dime]

I know one difference between the two engines is the spacing on the sprocket for the final drive. Is that easily overcome?

Yes, I believe so.

I did the opposite, K8 motor in an earlier frame, no problem.  I used a different rear sprocket carrier so the chain would align properly.  The K8's used a larger chain but again, no issue.

The other thing is I believe this would be coming with the 76 wheels as well. So it is possible to leave the 76 engine as is and use the sprocket carrier from the 76? Or the entire wheel assembly?

If not I am not apposed to splitting the cases and adding the 78 output shaft to the 76 engine to work with the 78 wheel assembly.

Had intentions to convert to 530 chain either way with the 78

[Stev-o]

Fairly certain the '76 sprocket carrier will fit the K8 rear hub [I dont recall what I did here but again, was not an issue]

Dont split the case, not necessary and could be opening a can of worms!

[Dime]

Fairly certain the '76 sprocket carrier will fit the K8 rear hub [I dont recall what I did here but again, was not an issue]

Dont split the case, not necessary and could be opening a can of worms!

Ya I was just thinking about servicing all the tensioners and what not while I am in there. I haven't really gotten that far in my research yet. Just going off my knowledge of the dohc.

[scottly]

I know one difference between the two engines is the spacing on the sprocket for the final drive. Is that easily overcome?

There are offset front sprockets for this purpose.

[Dime]

I know one difference between the two engines is the spacing on the sprocket for the final drive. Is that easily overcome?

There are offset front sprockets for this purpose.

I saw one at cogno moto for like $166 USD. That seems steep. Any other sources?

[Dime]

Ok. So I found a post on another forum I am on where the guy had a 77k with a 76k motor in it. He used the 76 style sprocket carrier and just had to machine a spacer for the axle. The chain guard also had to be mounted on the other side of the mount with a spacer.

This seems like the most logical way to go about it.