750F2 erratic tick over.

[royhall]

I think this may have been covered extensively as it appears to be a common problem.

Cant seem to get a good reliable tick over with these PD carbs. The bike runs superb, but as the engine warms properly the tick over gets faster. Also if I turn the throttle control hard backward, to tension the close cable, the tick over drops. I have checked the setup of the cables and there is plenty of slack on them and the return spring pushes the shaft hard back against the throttle stop.

The carbs have been completely apart and thoroughly cleaned etc. I have however just noticed that two of the felt washers on the spindle shaft are missing, would that cause a problem? Does anybody know where I can get a set of these felt washers. Cant find them anywhere and they don't even have a part number in my book.

On the idle screws, can I just verify I am correct. When the screw is turned out does the idle mixture get richer or leaner?

Will get to the bottom of this eventually, just need a bit of patience and effort, "O" and a load of help from you guys again.

Cheers all.

[Lobo]

Hi Roy,

I had this felt washer prob when rebuilding my 400F carbs, and frankly was unsuccessful @ making new ones as per all the advice on the Internet.

In the end I bought a job lot of assorted vinyl grommet type washers, and bingo there was a size that fitted beautifully. Haven't looked back....

Book figure (F2) from my manual is the pilot screws @ 1.5 turns out.

I'm no F2 expert, but saw this on an F2 thread... I read it as screw gently home = lean.

"The pilot screws block the entire pilot circuit from delivering fuel.  If the acell pump is working and the throttle held open the engine will start and race, but dies at/near idle settings."

The below possibly of use, (type "Felt" into the search box of first link)

Good luck,
Simon

http://www.motorcyclecarbs.com/search.cfm

http://www.hondachopper.com/garage/carb_info/tuning101/carb_tips.html

[martin_uk]

Did the carb clean include removing push fit pilot/idle jets?

[royhall]

Cheers Martin. Yes it did, I cleaned everything manually including taking out all the pressed in stuff and running through with a guitar string, then they were ultrasonic cleaned, then I cleaned them again. Mystified about the way twisting the grip backwards to tension the return cable drops the tick over. Wondering if I put enough turns on the return spring when I built them up, but it is returning hard to the stop? Plus there's a few of the felt spindle seals missing so I think the carbs may be coming apart again? Sigh. I suspect I may still have air leaks at the intake rubbers.

[martin_uk]

Did you get old O rings out of mixture screws orifice OK?

Spring on screw, then washer, then  O ring.


Have you double checked the fast idle part of choke linkage is clear when not full on and make sure linkage connected to cable  "toggles" ? (assume F2 has cable choke)

Sorry if Im covering points you have already checked.

[billy192]

not sure if your model has an automatic advance and retard thingy, but mine (K6) had erratic tickover. i changed carb rubbers jets, air filters but when i checked the advance re-trad ting it was dry and sticking. now after cleaning and a light bit of oil the tickover is brill, just a thought
Billy

[royhall]

Pretty sure I got all the above suggestions right when it was built up, but will use the suggestions as a list to double double check everything. Thanks guys.

[Bryanj]

I'm trying to remember what they were like new and it comes back that they just would not tick over at all untill really hot

[royhall]

That's exactly the problem Bryan, and its absolutely miles before its hot enough. Can be a real pain in traffic. Got to set the tickover so its usable, then when its hot the tickover is way to high. May try adjusting the fast tickover on the choke so its can be slightly on without the butterfly's closing so I can keep a bit of choke cable out until its hot. Not sure if that's possible though, and if it is its only a workaround. Should really start with finding a way to set the idle mixture accurately.

[Bryanj]

Again from aged memory I think you had to have the choke out a bit for quite a while, it was the Yanks fixation with the emissions making Hond fit the PD carbs which, in my opinon, were not the best---in fact a large pile of pooo

[royhall]

Again from aged memory I think you had to have the choke out a bit for quite a while, it was the Yanks fixation with the emissions making Honda fit the PD carbs which, in my opinion, were not the best---in fact a large pile of pooo

Ditto that Bryan. Think your being a bit generous to the PD's there. Only a pile of poooo, I've invented new swear words that go with PD's.

[steff750]

  while we are on the subject of them poo carbs ive never liked them either e.g. why have a accerator pump on one carb
i have a f2 engine and carbs on my sidecar outfit and if it was not for the electric start i would be kicking my guts out on every junction this bike has never idled properly in over 15 years
i have often thought of fitting k series carbs and insulaters to my f2 engined combination any body ever done this ?
what do you reckon guys will it work? any thoughts bryan?

[royhall]

I asked this question a few months ago, never really had a useful reply. On the American site its said that the inlet spigots on the F2 head are 2mm larger than on the K. So I guess you wont get carb rubbers to fit. Not confirmed though.

[steff750]

  yes ofcourse they have bigger valves so what if u used f2 insulators i wonder

[UK Pete]

I was considering bigger pilot jets in the f2 carbs, that could help out
pete