FRANKENHONDA II the 1982 DOHC CB 750F2 Build

[cb250nproject]

So I delved a little further into the CR carb situation. After I removed the top cover it revealed the shaft that actuates the slides and it had holes in it

There were two nuts inside the outer one was an 8mm hollow bolt with a screw in it (flat head screw driver required)

Once these bad boys were removed the carbs moved along the brackets freely onto the next hole in the shaft. For the Cb you basically have to outer two carbs as far to the left and right as the brackets will allow

Then true to form after the spacing was right I went to attach them only to realise carb number 3 contacts the bolt for the oil delivery line to the heads .

Now I’ve had to call on Old Man Murphy because we need to rework the adapters to be about an inch longer, shattered after all the work he did on the previous ones which came up a treat.

There will be no first start this break oh well it’s a marathon not a race this build.




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[LightsOut]

Good progress with the engine! Must be frustrating with the setbacks, but as you say - it’s not a sprint Öhlins look great on there btw!


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[cb250nproject]

Thanks, after having the internet go out and spending 2 hours on the phone trying to sort that out. These setbacks don't seem so bad, and yea I stop and smile each time I walk past the back of the bike and see the Ohlins now

I ended up making an amature youtube video on how i re-spaced the carbs

https://youtu.be/fHNFxsei1pM

Once I get off the phone finally ill probably go about finding a mounting point for this RFID key finally

 

[Jimbonaut]

How much clearance are you missing? Any chance you can sand that bolt down a bit so that the carbs fit?

Edited to add - nice to see I'm not the only one who works on their carbs in the kitchen. Did your wife kick your ass into next week as well?

 

[Maritime]

I was just thinking can you swap the banjo for a different style fitting? It may be a lot easier than changing the carbs.

 

[cb250nproject]

How much clearance are you missing? Any chance you can sand that bolt down a bit so that the carbs fit?

Edited to add - nice to see I'm not the only one who works on their carbs in the kitchen. Did your wife kick your ass into next week as well?

I was going to put a disclaimer for safety reasons ensure you have allowed adequate time for you to set up complete and clean up before your wife has returned home.

I’m not sure about sanding the bolt down I honestly think it would nearly be all gone to create enough clearance


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[cb250nproject]

I was just thinking can you swap the banjo for a different style fitting? It may be a lot easier than changing the carbs.

What sort of fitting are you thinking ?


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[Jimbonaut]

Are the carb>engine rubber boots stock? Or do the CR carbs have shorter outlets? I'm curious as to why there's so little clearance there.

 

[cb250nproject]

The adapters were custom from OMM we were just going off the previous spacers, and didn't even take into consideration the spacing required for the banjo bolt. Another thing I've just realised ill have to look at now is clearance for the petcock on the other side.

Todays jnrs swimming class so it will be a half day at best in the shed, see what happens.

 

[Jimbonaut]

By adapters do you mean the rubber boots? (the ones that connect the carbs to the cylinder block)?

 

[cb250nproject]

By adapters do you mean the rubber boots? (the ones that connect the carbs to the cylinder block)?

The boots are OEM these are the adapters


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[cb250nproject]

OMM is back at it in the shed he’s just turned up the top bearing cap once we have that sorted then we will need to modify the topside of the triple


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[Maritime]

After the discussion in Jim's thread about brake line fittings you can use instead of banjos I was thinking there could be one for the oil line that fits in flush instead??? Maybe Irk can shed some light as he use AN fittings on brake lines to eliminate the banjos?

 

[cb250nproject]

After the discussion in Jim's thread about brake line fittings you can use instead of banjos I was thinking there could be one for the oil line that fits in flush instead??? Maybe Irk can shed some light as he use AN fittings on brake lines to eliminate the banjos?

I don’t think they would provide more clearance based on the pictures in Jim’s thread.


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[cb250nproject]

So the other night my brother in-law visited, so I seized the opportunity to put the motor back in the frame. So between my brother in-law, a jack a block of wood, myself and a whole heap of swearing we got it back in.

Due to a lack of free hands there are no progress shots.

I put the exhaust on clearance is like 90 mm should be 140 mm... I’m going to scrape no doubt, so tomorrow I’ll take it off the stand and do a few more measurements. Fork extenders may give me that extra little bit I need, although I have my doubts.

Got to take my dog to the vet tomorrow so I can’t see much getting done, but I’ll try to make up my spark plug leads and cut all the wiring to length tidy it all up.


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[Kunphushun]

That looks great. The time you put into the seat pan shows. That exhaust is low though. lol

 

[Jimbonaut]

Good job on getting that engine in mate, it's a ball ache to be sure. Looking clean as a whistle and sharp as a pin. What's the plan with the exhaust?

 

[cb250nproject]

Jimbo,

I'm not really sure a few people have run two 2-1 for better clearance but I dont think thats necessarily good for performance. that said neither is scraping your entire exhaust away every time you make a right hand turn.

See how we go still a while away from Frankenhonda moving under its own steam so ill add that to the list :/ ...speaking of lists I will probably create a punch list of things that need to be completed to help keep me on track.

 

[Jimbonaut]

Is that exhaust designed specifically for your model 750? Can you adjust the exhaust hanger or the angle that the headers join the collector?

 

[cb250nproject]

It is specifically for my bike but I’ve got the gsxr forks and 17” rims


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