1977 400F2 first restore project

[smoothoperator]

Took the first dowel out using a drill chuck and bolt through it, it came out stupidly easy as it turns out. The chuck did squash the dowel a little so if I do that again, I'll wrap the screw in tape or perhaps find a close fitting drill bit. Anyhow, suitably confident that these dowels might not be in tight I removed the next one with pliers with little effort and no damage. Got the kick start oil seal out in semi reasonable condition as it is going to be used in the new case just for a short run before the engine strip down. The replacement case already had a seal in it where the clutch thrust bolt comes through. The ball bearings are very knackered so I've sourced a replacement from Julie.

[smoothoperator]

Refitted the clutch thrust bearing with a replacement cage and shiny ball bearings. I've left one screw out where the case was broken as the thread is damaged in the case. Measured the depth at 16mm so I don't think there is any broken screw in there, however I'd rather look at trying to fix the thread when the engine is apart. Even though I only plan a very short test ride I can't bring myself to pour the old oil back in so I've managed to find 5L of 10W 40 at £10 on amazon so I'll put that in hopefully tomorrow, swill the tank with some petrol then refit. Then I will have run out of excuses to go for a ride.

Should I expect any difficulty getting fuel through to carbs as the fuel pipe won't be full after having the tank removed for 3 weeks?

Next question, assuming it runs OK, should I check compressions? I feel that It would make sense and would be a no brainer if I had a compression tester. Can anyone recommend one? There are some for under £20 on Amazon and a shedload on Ebay, many of which look identical with numerous brand names, often in the same red plastic box, mostly around £10.

[robvangulik]

Why would you want to know the compression, assuming it runs OK.

[K2-K6]

This type is generally reliable and you're paying for the gauge not all the plastic and parts in the "kits"

https://www.mandp.co.uk/products/compression-tester-push-in-type-594478

As they run pretty well on varying levels of psi efficiency,  I'd want to know before stripping it where they're at as reference.  If nothing else it contributes to a working list, and when added to internal inspection, helps you in making decisions as to level of work desirable when you're in there.

[smoothoperator]

Why would you want to know the compression, assuming it runs OK.

I can sometimes be a bit anally retentive.

[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.

[robvangulik]

I agree with Nurse Julie, if the front feels bouncy it needs some more attention!

[McCabe-Thiele (Ted)]

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

Pleased for you I've only reached the engine running stage so far.
Out of interest have you fitted a small clear plastic inline fuel filter?
I fitted a small one with a 90 deg outlet - it serves two purposes
1) To filter the fuel to protect my carb jets etc.
2) To act as a visible window for fuel flow especially when the tap is in the off position.

So far it seems to work well you can see the fuel level in the plastic bowl start to partially fill up when you turn on the tap. When switching off the engine I turn off the fuel for about 5 seconds before I switch off, this drops the level slightly so I can see any seepage past the fuel  tap. It least that my hope!
fuel filter top right by Teddy Bagshaw, on Flickr

[smoothoperator]

Thanks Ted. I haven't installed an inline filter. I did fit a new filter in the tank as it was part of the service kit from DS as the tap was leaking. I think you did the same? So far the tap is leak free and it turns fine. I did fit the 2 O rings as recommended by DS. So the list of what I have done so far is:
Fix leaking fuel tap
Evaporust treat the tank
Fit a new battery
Get the front brake "working", more to do there
Replace the broken clutch case with a second hand one
Install replacement clutch actuator thrust bearings
Get the indicators working, they have since stopped so more to there also!
Go for a test ride

I'd like to go for another test ride to get more of a feel for how the the bike is running before starting to take it to bits, so priorities now are, improve front brake, new pads and adjust the gap between the floating pad and the disc, something I haven't got my head around yet. Get the indicators working again. Fit a mirror on the rhs will means tapping out the master cylinder mirror stem hole. If I fudge that up then I'll probably buy the DS Master Cylinder which is cheap. I'm pretty sure both mirrors are original however the right hand one is missing most of it's thread, it was in the MC. It's a shame as the left hand one is in amazing condition for something so old.

[McCabe-Thiele (Ted)]

I'm also toying with the idea of a ride before strip down unfortunately I have no headlamp or mudguards fitted......
mmmmmm

[smoothoperator]

Do it. Avoid nightfall and mud. Have a mirror though as you'll need to look out for the rozzers.