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1977 400F2 first restore project
McCabe-Thiele (Ted):
I would rock the bike gently from side to side as you switch on the fuel - this might avoid unnecessary flooding due to the float needles being slightly stuck in the down position if the floats are dropped down from the normal position.
I was on the verge of taking my carbs off when they flooded on my first try to run the engine - did the side rocking and all was good - they have not flooded since - its easy to jump to conclusions about the cause of flooding especially if you have re-set float levels or done a carb strip down.
I checked my cold compressions after 12 years of not running - the good thing was they were all pretty much the same a not very inspiring 80 psi with the inlets plugged up!
After unplugging the inlets I tried to check the compressions again first two read 110 psi - then the gauge broke - it was a 50 year old Crypton Unit with a cracked housing and the rubber tapered end fell to bits! I plan to check them again with a cheap unit I bought on e-bay for £10.99 - the kit is better than I expected for the price.
My late fathers doctrine was don't check compressions if you do not have a problem as you will always be disappointed in the result!
True compression test is when the engine is up to running temperature of course.
smoothoperator:
Red Letter Day. Engine started after just 3 attempts. Soon warms up and choke reduced then off after a very short time. So far so good. After running for a couple of minutes revs' started to rise up to 3000. Switch off, try again, same issue. Start think that the helmet laying on the floor ready is hopelessly optimistic. I did have the bike running a month ago and hadn't touched anything that would directly affect things. Head scratch and start thinking well here's the first sign that I'm going to have to get serious with the carb's and then thought let's try the idle screw and holy moly a less than a quarter turn and the tick over settled down fine. Helmet on let's go. Tried the brakes and wow the back one locks the wheel easily on our recently resurfaced street. Just as well because the front brake is, struggling for the right words, ineffective, hopeless, only for the brave etc. Anyway brakes tested and onto the main road with no dramas, rode through all the gears up and down, kept the rev's below 5000. Front end somewhat bouncy but overall one of those smile on your face moments. Checked the voltage on my return and it was giving 14.5v at about 1500 - 2000 rpm. Relax for a bit and chew on what to do next. Remember to turn petrol tap off. Have been reading engine full of fuel and seized up thread. I'll just go and check that tap is still off.
Back from the road test, oil catcher at the ready.
https://photos.app.goo.gl/bJrerK3GnwM7fq7U7
philward:
Good to hear a good outcome. I find that all the 750's (no experience of 400 recently) feel a 'bit bouncy' and that front disc is rubbish (better but still not great with twin disc'ed CR750 Rep).
I think that they are all the same when compared to modern bikes.
Nurse Julie:
Great work, nice that it and you got a little ride out. I find the 400/4 quite tight and positive at the front end.
K2-K6:
Sounds good progress, and always nice when you get them running for a test ride.
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