Author Topic: F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?  (Read 3356 times)

Offline Rozabikes Tim

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F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?
« on: December 22, 2009, 09:04:15 PM »
During my search for a 750 to buy, there are all too many comments on this site to warn against them for "chocolate motors"

Is this always the case or can they be reliable? Is poor reliability allied to lack of correct maintenance.

Appreciate any comments.
One day I'll have the time to restore it, not just talk and dream....

Offline hector2800

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Re: F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?
« Reply #1 on: December 22, 2009, 09:17:50 PM »
As far as I know the only real weakness is the valve guides which were modified from other models in an attempt to boost power output with bigger valves. That worked but it meant the reliability suffered somewhat compared to other models. My first F2 in 1981 had a really bad smoke problem on overrun which turned out to be the valve guides. I had new ones fitted and had no more trouble. Otherwise it was a great bike if you allow for handling of that era compared to modern bikes. Toured Europe three times subsequently and had no problems at all. The speedo said it would pull 130 flat out downhill and two up whether thats reliable I leave to you.
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Online Bryanj

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Re: F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?
« Reply #2 on: December 23, 2009, 06:33:48 AM »
Parts are different and not as easy to get as the "K" models due to the short (2 year) production run and it only really the exhaust valve guides that give trouble---if you dont do them when they need it you can get broken valves, holed pistons etc but look after them, ride them hard and be religous with the oil/filter changes and they will last 100,000+

Offline Spitfire

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Re: F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?
« Reply #3 on: December 23, 2009, 09:21:43 AM »
As Bryan says, the F2 motor was the most powerfull SOHC CB750 motor, the bottom end is bullet proof and it's only the valve guides that are dodgy. Like all the CB750's they need regular oil and filter changes but apart from that they are very reliable.

Cheers

Dennis
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Offline Yoshi823

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Re: F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?
« Reply #4 on: December 23, 2009, 11:03:38 AM »
I'd go with the above comments.

My 750F2 was extensively modified and it was very strong in the engine department with a polished,balanced crank,con-rods and a lightened rotor. The pistons were Yoshi 823 big bore, a reprofiled cam, bored and polished carbs, ally/bronze valve guides, valves seats recut to 30/45/70, S&W valve springs, polished ports, modified standard exhaust, free flowing secondary exhaust, uprated brakes and suspension as well as a modified frame so's to be able to change the cam to a higher lift without taking the engine from the frame.
Shame it all ended with a head-on with a car.
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Offline Rozabikes Tim

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Re: F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?
« Reply #5 on: December 23, 2009, 11:26:47 PM »
As Bryan says, the F2 motor was the most powerfull SOHC CB750 motor, the bottom end is bullet proof and it's only the valve guides that are dodgy. Like all the CB750's they need regular oil and filter changes but apart from that they are very reliable.

Cheers

Dennis


What about availability of parts such as valve guides. Again have read comments about spares for the F2 motor being hard to get. Is there an option on uprated / higher spec valve guides.

Also and off on a tangent -  did F2 come with electronic ignition as standard or was this the last of the points models?


One day I'll have the time to restore it, not just talk and dream....

Offline UK Pete

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Re: F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?
« Reply #6 on: December 24, 2009, 12:20:24 AM »
The parts for the F2 are getting harder to find, for example pistons ,rings and valves, i would say the fact that there are plenty of them still running and on the road would suggest they can last, apparently the valve guides are the first thing to wear out, but are easy to replace and still available, also the valve tips can take quite a beating the fix for this is to instal lash caps, nearly all engine parts for these black engined F2's are available, dynoman & cycle x in the USA make piston kits, ss valves, springs , cams ect, if you look around and have a large wallet anything is possible, i am rebuilding one at the moment , i dont expect to do more than 1000 miles a year on it so once rebuilt it should be good for a long time, you have to remember that k models also have there problems its not as if they go on for ever with out anything wearing out, but the production run was long so parts are a bit cheaper, and easier to get in some cases.
I have 14 bikes and if i go on to any forum there always seems to be negative coments about any one of them, i think there is nothing better than to make up your own mind , my opinion of the F2 is it is the last and the best of the sohc Hondas and a fast appreciating classic,  i may change my veiws when i have finished it , if a k model came up for the right price i would also like to own one of them one day. oh yes the f2  have points, but aftermarket electronic igniton is available still
Pete

Offline SteveD CB500K0

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Re: F2 MOTORS ANYTHING GOOD TO SAY AOUT THEM?
« Reply #7 on: December 24, 2009, 09:04:41 AM »
I agree on the future classic thing. Buy now while you can.

A good (gold) K2 will cost you
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