Jumped into the deep end

[MikeFlorendo]

You might have a new bottom case motor due to a thrown chain . New replacements come without engine numbers , you can see the rectangle behind the starter on mine . Check the sump isnt full of oil , sometimes they will leak past the check valve and fill it when left for a long time . At least you should have less ignition problems with the dyna . I just did my tank in my 77F2 and I used evaporust when I first did it , but it came back . So I did vinegar the second time and all good so far . Check your valves mine had 29000 miles , it seems they have a bit of a fault from factory and can be floogged out . So mine looked like this

Thanks I am so out of my element but loving learning so much everyday. When you know nothing you learn so much. I'll check the sump today. Should I take the cases off before I do the compression check to see what it looks like or just fill it with oil and do the compression check when my battery gets here? Thanks again!

 

[MikeFlorendo]

You might have a new bottom case motor due to a thrown chain . New replacements come without engine numbers . Check the sump isnt full of oil , sometimes they will leak past the check valve and fill it when left

Yeah, I looked at another bike a month ago that had case repair from a thrown chain and he said he had a blank case he would throw in if I bought the bike. Common I guess.

 

[MikeFlorendo]

You might have a new bottom case motor due to a thrown chain . New replacements come without engine numbers , you can see the rectangle behind the starter on mine . Check the sump isnt full of oil , sometimes they will leak past the check valve and fill it when left for a long time . At least you should have less ignition problems with the dyna . I just did my tank in my 77F2 and I used evaporust when I first did it , but it came back . So I did vinegar the second time and all good so far . Check your valves mine had 29000 miles , it seems they have a bit of a fault from factory and can be floogged out . So mine looked like this

Sorry tried to look it up but it wasn't clear. I try and find answers before I ask but how do i do this? "Check the sump isnt full of oil , sometimes they will leak past the check valve and fill it when left for a long time ."

Thanks I'm basically like I said in my thread jumped into the deep end. I'll try not to destroy the bike. Haha..

 

[pickleknuckles]

OK, thanks ill get new oil.

Don't forget you have a wet clutch that needs JASO MA or JASO MA2 type oil so it doesn't slip.

 

[MikeFlorendo]

Don't forget you have a wet clutch that needs JASO MA or JASO MA2 type oil so it doesn't slip.

Will do! Thanks

 

[dirtdigger]

Cycle X has all the parts. Used to be in the days you used bronze guides. Cycle x has new cast iron guides. Cycle x has new retainer and spring set. I use titanium spring retainers.

 

[kirky]

not a good idea using cast iron guides in an ally head because of the expansion rates.

 

[dirtdigger]

not a good idea using cast iron guides in an ally head because of the expansion rates.

well what do you think the stock ones are? as well as the valve seats. They are not aluminum I guarantee. Cycle x has been selling and using them for years. Automotive aluminum heads come with cast iron or some sort of steel guide and seat. The bronze guides wear at a faster rate.

http://www.cyclexchange.net/Valve Trane/Oversize High Lift Valve Guides.JPG

The cylinder liners are cast iron in an aluminum block....

 

[hinksy]

Mike , these motors are dry sump , there is an oil reservoir tank behin the right side cover . Just undo the sump plug and drain into a clean container if you want to reuse it and refill the reservoir

 

[MikeFlorendo]

Mike , these motors are dry sump , there is an oil reservoir tank behin the right side cover . Just undo the sump plug and drain into a clean container if you want to reuse it and refill the reservoir

OK, my confusion. Yes knew about that. Your comment made me think there was a sump that should have no oil. The dry sump is empty. I just got a telescoping light to look in and also check the the tank. Thanks

 

[MikeFlorendo]

Got a telescoping light and finally got a look in the tank. Pretty crispy inside. I'm still going to try and clean it out. Whats all th3 black flakes? Just crazy rust? Thoughts? See photo of stuff in the bucket. All that came out of the tank!

 

[MikeFlorendo]

Got the air box off. Not sure if there is jet missing (not sure if that's what it's called) from 3rd carb. The brass looking things. See photos 1. Choke works. That's something. Besides that no clue what I'm looking at.

 

[Kab wilcox]

New here, new to CB 750's and new to building bikes. I decided to have a project bike. Decided on a CB750 a few months back and just got one yesterday. Looks like a previous build. Found it in an impound lot. I dont know anything. I will learn as I go. If it takes me 3 years than so be it. I have 2 other modern bikes to ride.

Anyway, got the tank off. It's full of rust and crap but I think salvageable. Bought some Evaporust. Got the tank off and carbs are seized. Throttle body won't even move. Took the seat off. It was fabricated by Peter Chase of Cafe Cycles. I hit him up thinking might be his build but it's not. There is no oil in it and was covered in oil all underneath. That's as far as i got since yesterday.

Question, how do i know what seals to buy? Case has no numbers its obviously not stock because its not painted black. What year do yiu think the engine is? Does the tank really only stay on with the 2 rubber grommets in the front and a rubber piece at the back of the tank? I'll have 10,0000 more questions but thats good for now. Finally am i crazy or a stupid for taking this on with no knowledge? Here are picks

Classic 750 online will have most of what you need but try and save those carbs. They can get expensive trying to replace them. My CB740f was a three year project and this season I will be enjoying the ride that I spent so much time on.
Also get your gas tank lined it will cost a bit but it is worth it in the long run. Plus a bike wrecker will have things like wiring harnesses. Just a couple of things that I came across when rebuilding mine. Good luck and have fun with it.

 

[MikeFlorendo]

Classic 750 online will have most of what you need but try and save those carbs. They can get expensive trying to replace them. My CB740f was a three year project and this season I will be enjoying the ride that I spent so much time on.
Also get your gas tank lined it will cost a bit but it is worth it in the long run. Plus a bike wrecker will have things like wiring harnesses. Just a couple of things that I came across when rebuilding mine. Good luck and have fun with it.

Thanks, I will salvage anything that is in working order or can be rebuilt fairly easily. Hopefully no major issues. Would like to be riding her in a year but if it takes longer than so be it. I know very little so. I'm going to probably do some of the things 2-3 times to get it right. That's just what I've experienced when learning something new.

 

[Kab wilcox]

What year is your ride mine a 1980

 

[MikeFlorendo]

What year is your ride mine a 1980

What year is your ride mine a 1980

My vin is 1977 but the engine is not original and has no numbers on the case so it's a mystery until I take off the cases. Still waiting on the battery to do a compression check.

 

[MikeFlorendo]

So i found the engine plate when I took the airbox off. It's a 78 engine? I looked it up the 3's start in 1978 but it stops at 3000001. See photo.

 

[hinksy]

Wow , the dark stuff looks like sediment of some sort . Does it crumble ? Oh , that no.3 carb has a different overflow pipe , hope all goes well when you open it up . Partzilla , CMSNL , David Silver Spares are good sources for original parts . Then you have CycleX , 4into1 , Partsnmore , and Z1 Parts for repo parts . Didnt know about the engine number being there it might be a K8 . Mine took me 2 years and I still havent been able to ride it , but it wont be long now . I just have to wait till this rain and these floods stop over here in OZ , then I`ll get her registered on the road so I can ride her

 

[dirtdigger]

3000001 is the starting number for the K8 ending 3062980. So yours is very late K8. Never seen the engine serial plate in that position.

 

[MikeFlorendo]

Wow , the dark stuff looks like sediment of some sort . Does it crumble ? Oh , that no.3 carb has a different overflow pipe , hope all goes well when you open it up . Partzilla , CMSNL , David Silver Spares are good sources for original parts . Then you have CycleX , 4into1 , Partsnmore , and Z1 Parts for repo parts . Didnt know about the engine number being there it might be a K8 . Mine took me 2 years and I still havent been able to ride it , but it wont be long now . I just have to wait till this rain and these floods stop over here in OZ , then I`ll get her registered on the road so I can ride her

Nice! I'll get my battery today and check the compression. There is no break fluid in either master cylinder. Should I just bleed it through and check for leaks or is there a flush I should do first?

Thanks-