F2 Engine

[kifer]

Hi All, I have acquired a 750 F2 motor which I will use at some point, The thing is it has been sat in a dry garage for about a year,
I know it has only 19000 on it and has never been touched all original screws etc complete with carbs etc. Other than putting it in a frame to try it what would you do to check it over?

[mick]

Hi Tom, i would take the sump and rocker cover off and have a look in both ends while you have the chance, cheers Mick.

[Waggles]

My F1 was a low mileage barn find. I was loathe to take the motor out and strip it because of the mileage and I knew the general reliability of the motor. I took off sump and cleaned it and oil strainer, stripped clutch to 'unstick' it and check for rust ( there was none ) I replaced all service items and coils but as far as the motor goes all I did was pump some 20 - 50 oil for 'old motors' I got from Halfords around it ( plugs out and whizz on starter until oil light goes out for a bit ) and left that in there while I dealt with brakes etc. Reason for this was it has a 'seal swell' additive I thought would be a good idea, I also put a little redex down the plug holes. Changed the oil for 'proper' 10 - 40 before starting. Apart from a rather large cloud of smoke as she coughed 25 years of crud from her innards she now runs beautifully ( 'so far' he says touching wood etc ) I intend to change oil pretty frequently to begin with and keep an eye on the sump for rust but apart from that I will just ride and service as normal.

[kifer]

Thanks Lads, I will take your advice and do the checks as you say, I can toss some oil over cams before turning it over.
Was thinking about mounting it in a stand [ easier to store ] connecting up oil tank, turning over on battery then put meter on oil switch, I know it won't start but you do get a feel for them when they are turning over. What do you think about doing this ? I know it will be next year before it goes in a frame not even sure what next build will be like, want to build a MY BIKE a thing I have not done yet and age is not on my side  so needs to be done. Thanks Again.

[Bryanj]

Sorry to disagree but if its the Black engine F2 and it's done 19000 from new and never been touched the exhaust valve guides will be shot

[Waggles]

....... or replaced under warranty with original screws refitted ......... 
Bryan makes a good point though, you might want to check them out as its not in a frame, not a big job to see if they are OK and you would kick yourself if you found out they were shot once you put it in a frame

[kifer]

I presume the valve guide problem is due to mileage and not standing, Only heard this over last few years, back in late seventies
early eighties had a couple of F2's thrashed and neglected big miles with no problems [ except a sandstone wall in the Isle of Man. ]
Would like to know more Cheers.

[UK Pete]

I have seen untoched F2,s with 30.000 miles + still running ok with no smoke or noises, but then i have heard through forums that you are lucky to get 10.000 miles before they need work to the valve  guides,
Dont be scared off by all this talk , i think people only talk about worst cases, its almost getting the done thing to wright these engines off ,but when you talk to people with f2,s at bike meets and places there are many who are not on the forums and so are unaware of any issues.and have had no problems
 i spoke to a guy recently who has had no problems whatsoever, and he has owned 2 of them, both with higher milages than 30k, but as the others say do yourself a favour and check it out as the engine has to come out of the frame to get to the top end which is a pain in  the arse, if you do find your guides are shot then be prepared for a large bill unless you can do the work yourself
pete

[Waggles]

To be honest I feel a bit guilty for posting that jpeg and inadvertantly adding to the 'F2s are no good' myth. If you read my original post it was more to get comments on rather than scaremonger as it seemed a bit excessive to me. I too knew someone 'back in the day' with an F2 and he had no problems. We can only guess at why guides have failed ( lower gearing causing higher revs, higher redline too if I recall correctly, more radical cam, dodgy batch of guides? ) and I guess we have no figures on how many so the 'check it out' advice still seems sensible.

Would I have an F2? probably not, but that is more because I am an F1 fanatic and don't like comstar wheels than it is any engine worries, if I came by an F2 I doubt I would sell it! Lets declare a 'Be nice to F2s' month, they are after all the fastest sohc 750s. Anyone with an F2 should post their mileage and whether they have had problems, smallish sample I guess but it might prove something.

[kifer]

Thanks to all,  I think it is good to hear comments from both sides of the fence and I to are an F1 person, And sorry to some but not a lover of commie wheels,  As far as miles go I have had big miles off both models and I remember a lad in the early 80's doing best part of 80'000 before a major strip on his 79 F2.  Maybe there is some luck involved but I believe a bike in constant use mostly will produce higher miles with less trouble.
Sounds a good idea to find out what sort of miles has been had by the various models'
So over to you peeps out there.  Thanks again. 

[Galea]

From the sohc4 forums, makes for some interesting reading:

http://forums.sohc4.net/index.php?topic=10540.0

[kifer]

Wow cheers Galea, After reading all that I think I should weigh it in and buy a kwaka.

[Galea]

I wouldn't 

[Waggles]

I read the US post with interest. Now I have often wondered why there are oil seals on valve guides, surely you want a little oil to go down them? it makes sense thinking about exhaust gases getting into the oil via them.

SO this raises a question in my mind, would it be better to leave the seals off as long as you change the oil at around 1000 miles? ( as I do anyway ) would that improve guide life?

Still don't think its cause for panic tho, an awful lot depends on how you treat the bike. If you motor lives up around the red line mostly then it stands to reason it will wear out quicker ..... reckon I will use Hondaman's tip of greater exhaust clearances, can't do any harm and is simple to do.

[Galea]

Today I adjusted my exhaust valve clearances at 0.004" too.  No difference in engine tappet noise to my ears