SOHC.co.uk Forums > CB750

Candy Ruby Red k1

<< < (8/9) > >>

Bryanj:
Did you get the 70 reg you hoped for Pete?

Spitfire:
Just in time to catch the sunny weather !

Cheers

Den

UK Pete:
The reg is J which is 1971 the year of 1st registration in USA which is correct
Yes this bike is only ever coming out on sunny days, it will probably only do about 200 miles a year, as i have to share my bike riding time with many other bikes,
Pete

UK Pete:
Hi all, i manged to get out on the K1 today, other than riding round the block this was its first proper ride out on the road, i only took the bike up to 70mph, and just pottered around at legal road speeds, my first port of call was to yoshi's house to pick up some F2 parts he was selling, (thanks Tim) then i went for a long ride, as the bike got hotter a flat spot started to make its self known at about 2-3000 revs this got progressively worse as the bike reached it maximum heat at slow riding around town, so i went back home really content at this being the only minor problem with the bike, it rides really well and the brakes actually work reasonably well considering the age and only being single disk and drum , anyway when i got home i done a plug examination and found all the plugs really black and sooty, so it must be running really rich, i checked the air filter and that appeared to be new, so can any one suggest what would make it run so rich, i have a theory that the float height may be set wrong because if i leave the petrol tap on it stinks of petrol and leaks a small bit out when it gets picked up from side stand, or it may be the float needle not seating, these are just my guesses, can any one else add any likely causes
Pete

honda-san:
Hi Pete,
Glad you got out on it finally. My experience with using bikes which have been stood for many years is that it often takes a little bit of time and effort to get everything spot on.

Not too many reasons for running too rich on all four pots - air filter is the obvious one, even if it looks clean (I had a 350/4 which always ran rich, despite the air filter looking good. Fitted a new one and cured it instantly, AND improved mpg from 50 to 60). As you say, the one in teh K1 looked okay, hence it was left in.
The float heights were all re-set at 26mm, which is the standard value for a K1. Main jets were 120's which are correct for the K1. Slow jets were also the correct 40's. Carbs did not look to have been messed with, but can't remember if I checked the needle height (clip should be in the middle groove). Smell of petrol, and weeping from the carbs when stood suggests to me float valves not sealing. They are pretty reliable in CB750's I would suggest (indeed I have never had to replace any on my own bikes over the last 25 years).
The petrol tank was bone dry when it arrived from the US, with some light surface rusting I seem to recall. Wonder of the fresh fuel has washed any dust / dirt down which is holding the float valves off their seats - surprised though that all four carbs would be affected the same.

Might be worth removing the fuel tap bowl to see in any sediment has accumulated in it which would confirm whether or not any debris is being washed through from the tank which could then "upset" the floatvalves.

If you think I can help, just ask.

Cheers - Chris R.

Navigation

[0] Message Index

[#] Next page

[*] Previous page