Yamaha FZR400R - Restore'n'Rebuild (IMAGE HEAVY)

Had a bit of a play around yesterday while I did a service on the car - I THINK the issue with leaking coolant is the thermostat needs to be resealed, which will have to be done a.s.a.p.
Also going to try and replace the coolant hoses where possible as well. Going to be fun to play around in works Hose bin and see what I find

 

From what I can see the 400's are very similar to the 250 and 600, but is the only one with the alum deltabox frame which makes it so good

 

Huh nice, must have just been the 600 with the steel frame.

And hey, in my defence. When that spanner dropped it was really loud, totally thought I had blown the motor for a second untill I saw what it was haha

 

So it's been a while but I have an update!

I finally chased my mechanic down and had my throttle and EXUP cables remade so I can get down to "final" resassembly

But again, nothing works smoothly with this bike.
Cable end was originally at 9mm width.



Shaved down....



Finally within spec!

EXUP cables remounted on the valve, I pulled the valve out and cleaned it before I put it back in.... probably won't make a lick of difference but I really like making sure this bike sees the love it deserves.



F(*&*%*ING BIKE. It should be simple to make two cables run 1-to-1 and 2-to-2 but do you THINK I got it right first time? Yeah, not so much.



Because shopping is therapeutic and I really wanted them, I bought 10mm swingarm bobbins. Shiny parts make me happy.



Work courteously provided the race stand, for $50 with team discount, I really can't complain!



Assembled and in practice, WHY DID I NOT DO THIS EARLIER



The previous owners really made a mess of this harness... thankfully, I noticed this before I got too much further



Soldered up to prevent any issues, not my best job but I was hot, tired and thoroughly frustrated so it will do.



Fully re-wrapped and secured, so much nicer



Carburettors re-mounted and cables attached and 90% adjusted correctly.



Filters and tank test-fit with relocated fuel pump. Now attached to the Right Hand Side chassis, factory bolt points are sexy



Under tank clearance, looks good to me!



Another test fit, you can see the fuel pump just under the deltabox sticker on the frame.



I found this part in my parts bin, I really have no idea what the hell this part is



This is the only identifying mark I can find on it, anyone have any ideas?



I rolled the old girl outside to give her a little wash down with degreaser after noticing a lot of risidual oil and coolant after the incessant leaks that it has suffered



So I fitted all the fairing pieces I own and made myself realise how far this bike has come.



It's so close to being finished that I can almost taste it.

 

This is the first startup and idle after having all the parts fitted and finalised, runs quite well in this video but I now have a serious problem...

After this and 2 more startups, the bike will NOT start and while I suspect flooding and therefore fouled plugs I think the source may well be the carburettor.

The problem here is I have literally zero idea on how to adjust my carbs and what I need to do to get this poor girl back to a healthy running setup.

If anyone has suggestions and advice I would really appreciate it.

 

You can see in the video I got them around the right way in the end.

I ended up having to re run them anyway as my original route fouled the lower part of the drive chain. :/ so I fixed the orientation at the same time as that

 

.... That would make a lot of sense now haha, missing the left hand side piece though, bummer.

I have adjusted the EXUP, motor spins through the full range on start up nicely.

I eye balled the sync, but I think they could probably do with fine adjustment - I'll find my feeler gauge and do that next.

As for the pilot screws/idle screw etc - I literally have no idea what to set those at so I would't have the foggiest if they are set right.
The choke seems to have no effect right now, but the cable is connected and when I pull it, the slide and pieces all move correctly.

Spark seems to be fine, I may have to give it a test but when its running it sounds and feels like running on all cylinders cleanly.
But those coils are the bane of my existence so I don't relish the idea of them being at fault or I may need to rob a bank for some Dyna coils.

Aaaand I am pretty sure I have flooded it by now anyway, so I will get a set of plugs and use them.

I always let the pump prime up before attempting to start, my Goss aftermarket pump makes a distinctive noise and primes nicely.


In doing some research I also found that it is likely that I have cracked/minute splits in my manifold boots, the 26 year old rubber is bound to have died a painful death.
I have some new ones on order as well as some new airbox seals so i can refit the factory airbox as the Mikuni carbs apparently don't like pod filters, they like the airbox for pressure so that's another part that I need to replace.

 

I've been meaning to do a proper update for a while but uni is in the way. but today I thought it try some more tinkering.
Pulled the carbies off to find this!


Wtf!! How the hell did that happen!?!
I've siphoned and dried all the fuel out now but, what the flying focasia happened to make that happen?

 

But how did the fuel even get in there? The key is off, the fuel pump can't run and the petcock is lower than the carbs. O.o

 

After that fuel debacle I decided I need to strip the carbs down again, try and pin down the issues I have been having.

Shiny new jets, turns out that they aren't the right size (87.5) where the stock ones are 92.5 (Cyl 1&4) and 90 (Cyl 2&3) so they will be ordered sometime soonish.

All the others are the right size though thankfully



Cleaned up all the bowls and stripped all the parts off I could



Spare set of Carbies, I think they might be 3TJ ones - but enough parts are common to have saved my bacon many times
@maelstrom I also pulled those Emulsion tubes out finally, Uni/Work have been in the way - will send them off this week coming



My 3EN2 Carbies, all the parts are out and in the process of being cleaned

I broke a little brass bolt off many months ago, made a workable solution but it wasn't ideal.
Stage one of the replacement



Add nut to allow it to function



Works like a charm!



This was the old part, barely worked but did the job for the few times I used it :/



The carbs have gotten really dirty since I last cleaned them :/ Definitely time to clean





Checked all the jets, little damage but have been all cleaned thoroughly and gently - this should make all the difference I hope



Mostly reassembled and ready to be put back together





It turns out the clip on the needle was set to the highest setting, the main jets were a 110 size.... the previous owner royally buggered with those settings for some reason I have no idea, I reset the clip to 3 (middle) and jets to the new 87.5 I bought. This will still be a little lean but hopefully it will be good enough to let it idle and be balanced

Just need to check the float levels now.... little bits at a time haha