This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.
Messages - blackeagles
Pages: 1 ... 4 5 [6] 7 8 ... 10
76
« on: September 22, 2019, 12:24:04 PM »
you do not say what year and model? uk, usa or other
so, i'm going to assume you need a 41202-286-000 washer and a 90665-286-000 circlip. I cannot find a washer on the net although there is a rather pricy circlip on ebay usa
77
« on: September 22, 2019, 12:15:39 PM »
re-checked the timing and although it was a weeeeny bit out I have changed it and it's the same.
I should have said at the outset that this 'problem' only happens in top gear, running up throu the gears I can get it over 6k in each gear, in fact I have taken it to 7k (but I do not want to blow it up) but in top gear at around 40/45 mpg and with the throttle open it will belt up to 6k then no more!!
I do not like revving the life out of it so 5/6k is my absolute max but I have to say I am interested in why it does this.
78
« on: September 20, 2019, 04:45:16 PM »
Two very quick things spring to mind - is the choke mech allowing the butterflies to open fully, i.e. horizontal with choke off? Not too easy to check without removing the air plenum. Secondly have you got resistor plugs OR resistor plug caps fitted but not BOTH? One or other is correct.
I was out on my 350/4 the other day to meet up with some visitors and the bike would go ok but not rev freely unless I very gently coaxed it. Found out that I had caught the choke lever and moved it slightly with my gloved hand when I turned the fuel off to fill up. Not so much of a problem on the 400 as there is a larger distance between the two.
Ian
Just thought about observing the choke butterflies but haven’t checked - with the air filter element removed can you use a mirror to look through the plenum into one or part of the intakes? Dunno!
ok, thanks for that. I will check the choke. I did put a single plug cap on along with a new set of plugs but I have no idea if they have resistors in them - I will have a try at checking the type using the number printed on the plug.
I have since had a check and I replaced the d8ea with the same (d8es-l unobtainable) plug although I have managed t replace the cap with a resistor one whilst the other three are non-resistor but I guess this will not make any real difference top end rev wise?
79
« on: September 20, 2019, 11:21:30 AM »
I was doing a partial restoration of a cb400f2 but I have got a bit side tracked with a 750 f2, anyway I have taken the 400 out and it seems to 'go' ok but it does not want to rev above 6k. it has all stock size jets and the air screw is 2 turns out.
I am not keen on revving an old bike to high levels but am just interest what, if anything, I have screwed up!
any suggestions?
80
« on: September 20, 2019, 10:51:55 AM »
I took off the carbs yet again along with the rubbers, which were not as hard as I had expected, and gave them a good clean internally and refitted it all and there seems to be no air problem now. I have tried to sync. them but my 'kit' is one of those very cheap ones and only 3 seem to work (one just goes back to zero when adjusted) so when I sort this out then maybe I can get it finished before winter!! - which may mean a little honda to play with over winter - not telling the wife of course.
81
« on: September 20, 2019, 10:44:14 AM »
Think I've a F2 example I could measure to confirm for you, you'd need to post how much bare cable you've got sticking out of the external to see.
They don't have any real slack in them when fitted, you have to put on "non pull" first as it has no adjustment at all I believe.
thanks for the offer but a bit of internet searching seems to show there is 3cm difference in the movement (the early k's 6cm and the f2 9cm) but since I have now got it fitted I will leave it for the time being and maybe change both cables later. moorey, also the bike is uk so I guess the bars are also uk.
82
« on: September 17, 2019, 02:51:23 PM »
anyone know if there is any difference - length wise -between a push cable 17920-341-000 (which is fitted to the 750f and k1 to k6 and which is on my bike but seems to be sooo tight it is almost without any adjustment) and the correct one for a 1977/78 f2 - 17920-405-610
83
« on: September 08, 2019, 12:52:40 PM »
thanks again. I have found a couple of charts that show a '78 f2 frame number should start from 2k and the '77 one will have a frame number starting 1k, as mine so it must be a 77 model (there are bits of information on a frame sticker, one of which starts 77-nnnn), i'm mentioning this as another list I have found shows the 77 f2 had a 41b carb with the 42a introduced for 78 so other then the main jet being a bit larger than original i'm 'ok' - but from what I've read the records were not well kept back in the day so who really knows  . as far as the rubbers are concerned, this project was supposed to be my 'winter' project !!!  so i'm not in a great rush to find a set - I notice my ones have 410 stamped on them (same as the middle number of the part) along with the pot number so I will just keep looking until I either find a set at a 'good' price or use a k7 set which I guess will have 405 stamped on them if original.
84
« on: September 07, 2019, 10:36:51 AM »
Looks like you've just got a straight swap to K7 carbs complete with jets then.
It doesn't look much of a problem as Honda were chasing horsepower figures on the F2 in competition with other manufacturer bikes that were coming onto the market at the time. It's setup to run higher rpm peak than K7 which was orientated towards slower cruise style riding. You can assess the running once you get it going competently.
Carb rubbers, I'd not be encouraged that there is much of any choice regarding replacement and if not fixed they will run you raggedy with setup problems. Maybe some of the F2 owners on here could point out any other route for this.
I know what the choke / throttle lift does but don't have example to look at right now. Manual drawings don't show exact details of that screw but do request greasing of that part for assembly and maintenance. Presumably the screw replacement would reinstate the lift function, so worth considering.
It's not a show stopper if the throttle doesn't lift, it just means it won't reliably run during choke phase while cold starting so you'll just have to modulate revs yourself to avoid stalling.
It should ride fine otherwise, as choke flaps will make it respond ok to riding. In reality when they were new you'd want to get it off choke as soon as possible as riding at slow speed the elevated rpm use wanted to push it along too fast.
there seem to be plenty of carb/head rubbers advertised for the sohc k series including the k7 but I don't seem to be able to see many for the sohc f2 (most seem to be the wrong shape so may be the later f2) but since the 1977/78 k7 and f2 are effectively the same bike I will assume they use the same rubbers - need to check the part numbers!! as far as the choke screw is concerned, I have sent off for one although I have to say the picture of it looks the same as the one I took off (a close inspection seems to show the screw is almost like new and although the mounting was bent and I have put it back straight but the rest looks correct) but I will compare otherwise I will be fitting a screw to the adjuster screw to bridge the gap - i'm going to make this work if it kills me!!
85
« on: September 05, 2019, 04:00:18 PM »
ok, a sort of update.
since the pd41b and 42a bodies are the same (and given that I seem to have the wrong one on the bike) I have taken them off again and main jet is 110 and not 105 as its supposed to be (but I guess its not enough to matter) and the slow running is correct at 35 - I cannot see any numbers of anything else.
yes, k2-k6 was correct about a possible air leak, I sprayed some carb cleaner around the carb to head rubbers and the engine speed up and slowed when the liquid evaporated (although I do not know if it was one or all rubbers!!) any chance there is a sealant I can use or are we talking a new set - any suggestions from where as they seem to be quite expensive ?
the other thing which is more of a problem is that I notice when I pull out the choke knob the flaps close but the little screw that is supposed to contact a cam and raise the revs does not even touch the cam!! even with the screw in a far as it will go. either the cam is worn or the head of the screw that contacts the can is badly worn - I have to say they look ok but I am not that sure as I do not know what a new one looks like for comparison.
I am toying with the idea of drilling out the bit which contacts the can and fixing a small screw into it to close the gap 'hopefully' make it work
86
« on: September 02, 2019, 05:55:14 PM »
ok, thanks. I will have another go when I get time.
87
« on: September 02, 2019, 05:50:42 PM »
ok, so I seem to have the wrong carbs on the bike. I will have to take them off again and check the sizes of the jets (which I did not do the first time) when I have time
88
« on: September 02, 2019, 03:40:21 PM »
"the press in pilot jets block for a pastime" - I guess I am lucky as when I took the carbs off and 'fired' cleaning fluid into all the jets they were clear!!
89
« on: September 02, 2019, 03:37:20 PM »
well the ignition timing is ok but the choke will not get anything like 3000rpm yet the adjustment screw is all the way in (but the cam looks worn) and the 'screw' setting which is 1 3/4 turns out is also ok (not sure if this is correct for this carb, I've got PD41Bs but I was told they should be PD42A)
Anyway the problem continues with the revs going all over the place even with the carb closed!!
90
« on: September 02, 2019, 03:32:30 PM »
I have been trying to sort out a problem with my CB750F2 carbs and was recently told they are PD42a but I have just noticed mine are stamped PD41B. Anyone know what, if anything, is the difference and will it affect setting them up as per book i.e main=105, slow running=35 and a setting of 1 3/4 turns out etc??
Pages: 1 ... 4 5 [6] 7 8 ... 10
|
Show Posts