Author Topic: F Owners- What did we get ourselves into?  (Read 32376 times)

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Offline mikedialect

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F Owners- What did we get ourselves into?
« on: August 01, 2007, 10:34:36 AM »
So, I'm reasonably new to BIG bikes. I've been riding dirt bikes and scooters my whole life. I've ridden a 'motorcycle' for about 10k over several bikes. I think that makes me a n00b still, right? ANYHOW, I wanted a cb750 badly after I had a few other bikes and I jumped at my current ride- the 1978 Cb750F. Now, I had been trolling on here for a while and I was silly enough to know that I liked the looks of the F more than the K (oh, how the pretty stuff always gets all the attention!).  I had just assumed that the solid nature of the honda 750 was a cross platform thing. I was unaware of all of the issues that the F's had that the K's didn't. I know I've seen the red headed step child stated more than a few times on here when referring to the F's. I guess what I'm getting at here is this: What did we get ourselves into with the f's? Did the rest of the owners of the F's fall prey to the same thing I did? And to sum it all up- what should I look for specifically when I'm dealing with my F in terms of care, maintenance, etc. ?


-Mike
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eldar

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Re: F Owners- What did we get ourselves into?
« Reply #1 on: August 01, 2007, 10:40:52 AM »
Well the first Fs resemble the K bikes a more than the F2/3. the main issues that people have are with valves. Maybe dump the F engine and Get a K engine and just paint it. but Having a K8, I know about the stepchild thing. However, there are more and more late K and F bikes coming up and part suppliers are carrying more for us. It is getting better.

Offline UnCrash

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Re: F Owners- What did we get ourselves into?
« Reply #2 on: August 01, 2007, 11:08:05 AM »
I fell into my 750F...

Not literally but, I was looking for an older Honda and this came up on Craigslist for $400.  I couldn't pass it up.

$500 later in parts n tools to work on her seems to only have made me fonder,  even when you consider my events this morning. --> http://www.sohc4.us/forums/index.php?topic=24715.0

I'm just a monogamous kinda bike owner I guess.
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Offline mikedialect

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Re: F Owners- What did we get ourselves into?
« Reply #3 on: August 01, 2007, 04:01:05 PM »
Well the first Fs resemble the K bikes a more than the F2/3. the main issues that people have are with valves. Maybe dump the F engine and Get a K engine and just paint it. but Having a K8, I know about the stepchild thing. However, there are more and more late K and F bikes coming up and part suppliers are carrying more for us. It is getting better.


Well, I'm actually working on grabbing a K8 right now. So, who knows! I might be wandering into another debacle. I know that I could have purchased a newer, fancier, maybe pick up chicks bike already, but I just love the old 750's. Maybe I'm mentally challenged. Maybe I have 'issues'. I'm not sure. I've seen some of them being parted out recently and that's good and bad. *shrugs* I was just looking for a little sympathy today. Time to keep my yap shut!
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Offline mazingerzeca

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Re: F Owners- What did we get ourselves into?
« Reply #4 on: August 01, 2007, 05:04:51 PM »
My bike is a cb 750 K8 with a F2 engine on it. I started rebuilding it this winter; not myself, a mechanic is doing it, but I'm the one which gets deep into technical especifications, and I've learned a lot on this forum about this engine. The most important problem with this engine seems to be the wear of exhaust valve guides. My engine had a high oil consumption, and twice a year a spark plug appeared oiled. I hope to solve this problem with new valve guides. Maybe I made a mistake, but I'm going to install bronze guides (I say that maybe i made a mistake because later I have read here that these guides wear faster than steel guides); anyway, if they wear, next time I will install steel guides.
Another problem related to this engine seems to be the difficulty on availability of spare parts, specially pistons and rings, but I was lucky and found them; the cylinders have been overbored yet to 0.75.
I've seen that some people on this forum has replaced the F2 cylinders and head by K cylinders and head, but I was more conservative and decided to keep the engine as it was. I just changed the black paint into silver paint and polished the covers. I decided to keep the F2 head and cylinders because it was very difficult to me to find a K head and cylinders here, in Spain.
The engine will be finished in september, I hope, but there is one thing that I wish to read here before: a successfulstory on rebuilding a F2 engine that would bring some hope to us F2 owners  ;)

Offline mick750F

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Re: F Owners- What did we get ourselves into?
« Reply #5 on: August 01, 2007, 06:30:08 PM »
   Actually the 650 is the real red headed step child... ;) The only real problem...and it is a problem...with the F2/3 is the head design. When mine becomes a problem and that is a when, not an if, then I plan to do the only sensible thing. Swap the top end out for a K7/8 top end, head and cylinders. Problem solved.

   Mike
'
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Offline jtb

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Re: F Owners- What did we get ourselves into?
« Reply #6 on: August 01, 2007, 07:29:17 PM »
I just bought an old 750 engine for $10.00.  Haven't even checked the numbers to know what it is.  But it's my new insurance policy.   ;D
1977 CB750F
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Offline cben750f0

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Re: F Owners- What did we get ourselves into?
« Reply #7 on: August 01, 2007, 09:56:13 PM »
i love my F.......


 ;D peace
you are never to old, to act like a kid... be safe
funny thing,chasing someone down hill on a bike 30 years older than theirs..
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Offline Steve F

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Re: F Owners- What did we get ourselves into?
« Reply #8 on: August 02, 2007, 12:59:12 AM »
i love my F.......


 ;D peace
Ditto!  Only I'll make it I love my F(s) as in two F1's.  I don't have any unusual issues with either of them.
 ;D  ;D

Offline spitfire

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Re: F Owners- What did we get ourselves into?
« Reply #9 on: August 02, 2007, 01:34:58 AM »
I bought my 1976 F after owning a K0, K1 and K2, apart from the K0 I preffer the F, the handling and power were restored to K1 standards and there isn't the same issues with the engine as the F2.
The F2 is a big improvement on the earlier bikes with better handling and braking, there are a lot of K owners who would love the double front discs on the F2. The only downside is the valve guide issue and the lack of spares, I recently bought a spare F2 top end, everything from the crankcase up including the carbs just in case.

Cheers

Den
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1977 CB750F2: Restoration started
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Offline Wheelhorse77

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Re: F Owners- What did we get ourselves into?
« Reply #10 on: August 02, 2007, 09:49:22 AM »
I was told that if I wanted it, to come get it and it would be mine---free for the haulin.

Almost a grand later she's hanging with vipers in the mid range. she puffs oil for a while when it's cold, but hey, that's character.

This winter I have plans to tear into it and see what I discover---or sell it and buy a Suzi shafty---either way time will tell.
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: F Owners- What did we get ourselves into?
« Reply #11 on: August 02, 2007, 10:00:24 AM »
Once you go F you never go back!!  ;D

A little known fact is the 75 750F is perhaps the most rare 750 ever built. Even more so than the sandcast perhaps. They were produced for about only 5 months.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline dusterdude

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Re: F Owners- What did we get ourselves into?
« Reply #12 on: August 02, 2007, 10:45:11 AM »
dont feel bad guys,at least ya`ll dont own k8`s. ;D
mark
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eldar

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Re: F Owners- What did we get ourselves into?
« Reply #13 on: August 02, 2007, 11:29:04 AM »
Well there were only so many K8s. Not everyone can be so lucky! Them K1s though are a NICKEL a dozen! :D

Offline cben750f0

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Re: F Owners- What did we get ourselves into?
« Reply #14 on: August 02, 2007, 11:43:43 AM »
*runs away and get popcorn and beer*

!!!! ooooo them there are fightin words !!!!!!


um....er....peace ::)
you are never to old, to act like a kid... be safe
funny thing,chasing someone down hill on a bike 30 years older than theirs..
he said \\\\\\\'it was like watching a 250kg unguided weapon getting stuck up you bum\\\\\\\ http://www.bikepics.com/members/trixtrem/

Offline superchode

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Re: F Owners- What did we get ourselves into?
« Reply #15 on: August 02, 2007, 01:12:20 PM »
there's plenty of success stories... i just posted one a few days ago - full engine rebuild on an F.  virtually everything north of the pistons had to be replaced.

sourcing the parts isn't easy... but they're out there. this forum is the best place to start.




My bike is a cb 750 K8 with a F2 engine on it. I started rebuilding it this winter; not myself, a mechanic is doing it, but I'm the one which gets deep into technical especifications, and I've learned a lot on this forum about this engine. The most important problem with this engine seems to be the wear of exhaust valve guides. My engine had a high oil consumption, and twice a year a spark plug appeared oiled. I hope to solve this problem with new valve guides. Maybe I made a mistake, but I'm going to install bronze guides (I say that maybe i made a mistake because later I have read here that these guides wear faster than steel guides); anyway, if they wear, next time I will install steel guides.
Another problem related to this engine seems to be the difficulty on availability of spare parts, specially pistons and rings, but I was lucky and found them; the cylinders have been overbored yet to 0.75.
I've seen that some people on this forum has replaced the F2 cylinders and head by K cylinders and head, but I was more conservative and decided to keep the engine as it was. I just changed the black paint into silver paint and polished the covers. I decided to keep the F2 head and cylinders because it was very difficult to me to find a K head and cylinders here, in Spain.
The engine will be finished in september, I hope, but there is one thing that I wish to read here before: a successfulstory on rebuilding a F2 engine that would bring some hope to us F2 owners  ;)

Offline mazingerzeca

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Re: F Owners- What did we get ourselves into?
« Reply #16 on: August 02, 2007, 01:51:48 PM »
there's plenty of success stories... i just posted one a few days ago - full engine rebuild on an F.  virtually everything north of the pistons had to be replaced.

sourcing the parts isn't easy... but they're out there. this forum is the best place to start.

Great to hear about this. Sometimes reading about F2 woes one gets paranoid. What about the valve guides? did you replace them with OEM or bronze guides? Yes, the parts maybe are not as easy to find as for other 750s but everything appears, and the prices are similar to K series.

Offline Terry in Australia

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Re: F Owners- What did we get ourselves into?
« Reply #17 on: August 02, 2007, 02:40:30 PM »
I love my beautiful F2. One day I will tear the engine down again and fix the leaking crankcases, and respray the tank sent all the way from Texas to replace the rotted out New York tank I spent a fortune on, but until that day I'll happily ride my trusty K0, K1, and K2.

The 1975 F is rare, and the K7/K8 is probably rarer, but their "rare-ness" (if that's a word) is only surpassed by their ugliness, hence the rareness, even Honda couldn't go on building them, they couldn't stand the rows of vomit buckets lining the production line. Sorry, but it's true, they're great bikes, and reliable to boot, but if they were chicks, they'd be fat girls with great personalities, whereas the F2/F3 would be beautiful #$%*es with nasty dispositions..............  >:(

My sympathies lie with the poor bugger above who owns a K8 with an F2 engine fitted, geez, talk about the worst of two worlds! I bet the other guy riding the F2 with the K8 engine can't stop smiling, ha ha! ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

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Offline mazingerzeca

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Re: F Owners- What did we get ourselves into?
« Reply #18 on: August 02, 2007, 03:49:58 PM »
My sympathies lie with the poor bugger above who owns a K8 with an F2 engine fitted, geez, talk about the worst of two worlds! I bet the other guy riding the F2 with the K8 engine can't stop smiling, ha ha! ;D
The first time I saw her, I thought that it was not the bike that I was looking for. I didn't like that big fuel tank and that black engine (even not knowing all the woes that brings). But, I don't know why exactly, I decided to buy her. I FELT IN LOVE WITH HER. It was 5 years ago. Yes, for someone who doesn't know what loving a bike is, she can be fat, dirty etc. but you can not imagine how much fun she gives in the bed  ;D

Offline Terry in Australia

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Re: F Owners- What did we get ourselves into?
« Reply #19 on: August 02, 2007, 04:33:18 PM »
You take your bike to bed mate? Geez, now that's really sick, I thought New Zealanders were bad enough sleeping with sheep, but you're an animal! There's gotta be laws against that, even in Spain? :D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline 78 k550

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Re: F Owners- What did we get ourselves into?
« Reply #20 on: August 02, 2007, 08:02:16 PM »
You take your bike to bed mate? Geez, now that's really sick, I thought New Zealanders were bad enough sleeping with sheep, but you're an animal! There's gotta be laws against that, even in Spain? :D

Terry LMAO likes his beer but from the sounds of it never enough to sleep with her.  LOL

Paul
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marcshep

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Re: F Owners- What did we get ourselves into?
« Reply #21 on: August 02, 2007, 08:52:29 PM »
MMMmmmmm F

Offline Shenanigans

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Re: F Owners- What did we get ourselves into?
« Reply #22 on: August 03, 2007, 01:29:37 AM »
What? You think you did not have to trade off something for that rear disk?
   This pretty much sums it up.   76' CB592 cafe. 69 750 project, 03 CBR954, 75 750 super sport.

Offline superchode

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Re: F Owners- What did we get ourselves into?
« Reply #23 on: August 03, 2007, 06:48:02 AM »
Great to hear about this. Sometimes reading about F2 woes one gets paranoid. What about the valve guides? did you replace them with OEM or bronze guides? Yes, the parts maybe are not as easy to find as for other 750s but everything appears, and the prices are similar to K series.

used OEM guides... off the shelf from Honda.

Offline paxtonpony

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Re: F Owners- What did we get ourselves into?
« Reply #24 on: August 03, 2007, 07:56:56 AM »
K owners are such haters.  They didn't take their time searching for a good bike and just bought whatever K they came across first.  Maybe one of these days they'll finally find their F model on Craig's List.  It won't be mine though, my 75 F is mine for keeps.
 ;D
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1978 CB750K - Sold
1992 GS500 Streetfighter - Sold
1975 CB750F - Sold (sniff, sniff)
1994 VFR750F - Sold
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