Yamaha RD400F refresh

[rdshaw]

Howdy. I certainly wouldn't use those xs parts bin "specials"
Just my opinion. Plus I don't know what your end game is.
Thanks for showing your bike.

[SoCal250]

Howdy. I certainly wouldn't use those xs parts bin "specials"
Just my opinion. Plus I don't know what your end game is.
Thanks for showing your bike.

Hey Murray, haven't seen you around in a while.
Since this Daytona is far from stock, as it was was modified by its previous owner, I feel no obligation to retain "correct" OE bits on it. So I have some things planned for the refresh.

[SoCal250]

Progress is still moving along slowly just haven't updated this thread in a while.

The oil pump was torn down, cleaned in the ultrasonic with two 20-min cycles, and then rebuilt.

Before:








My 400 pump does not have the rear thumb wheel, so instead of two dowel pins and springs in the distributor it has only one long pin without a spring.


Done, and ready to reinstall.

[SoCal250]

One item on my long list was repacking the silencers, so today I had a moment to pull the baffles out of my pipes.
I think I discovered why one pipe was louder.


Hoping to get some time tomorrow to clean, repack and then reassemble.

[SoCal250]

A little progress today. While some tasks took several steps backwards and one went all the way back to the drawing board, I was able to get the pipes repacked and reassembled. Just need to twist and tie down the safety wire.

[SoCal250]

Got the pipes finished off with safety wire.


But the other tasks I was working on all ended in roadblocks. One even had two alternate solutions also fail.  Because this bike is a 1-year-model and because it's been customized by a previous owner, nothing is easy or straight forward. The simplest task can turn into a month long headache.

[SoCal250]

Still making progress on this project, just haven't done any updates lately. I've been trying to keep pace with Tim.

One task that was finally finished today was the oil pump that I started working on, and finished a while back. Turned out it wasn't really done.

I went through three oil pumps getting the right one for this refresh.   The original had some strange internal wear and bluing after being disassembled, and did not function properly following a rebuild. (Further investigation and troubleshooting to occur at a later date.) So I had to find another one.

The 2nd pump, which I pulled from my inventory the other night showed signs of a hard life and poor storage. It was super dirty, rusty, and it could have been an old junkyard part. The distributor shaft was so rusted that it could not be pushed through the housing even with the rear seal removed and after polishing the tailshaft with scotchbrite and emery cloth. (Further work and rebuild to occur at a later date.)  So I had to find another one. 

The 3rd pump I pulled from my inventory came from a bike in Canada and looked to be in excellent condition. It was the winning candidate. And since it was from an earlier RD400 I was able to add a priming wheel to my 400F, which was not a stock feature in '79.








I'm getting pretty good at tearing down pumps, swapping them out, and getting them shimmed and bled.

On to the next task...(which I've already done, but just need to post it here)

[Kawtriplefreak]

Beautiful work   

[Simmons1]

 

[SoCal250]

Yesterday was the first fire-up after a long nap. This bike has been displayed in my living room for the past few years.
Started 3rd kick and only needed 1/4 turn of the throttle screws for a perfect idle.
So I decided to take it out for a quick putt around the neighborhood. Only did a little over a mile, but everything seemed pretty good.

Today, so-cal-sdr200 and another riding buddy rode over to my place for the initial shakedown ride. The Daytona did a successful 20 miles with only a couple small issues to resolve. I believe one is now fixed, as I did a post-ride modification of the shifter that will be tested tomorrow. Monday is another shake down ride.

When I have some time I'll fill in all the details about the refresh project and add some photos.

[SoCal250]

Spent all afternoon again on the Daytona.
Double-verified pump function and that oil was being emitted by each carb nozzle, (call me paranoid). All was good.    Also added throttle slide opening marks to my handlebar for jetting checks.
Did another 27 miles of shakedown today after fixing my shifter issue. That problem is confirmed solved.

Tomorrow I'll be pulling the carbs again to tweak the pilot jetting. While I have the carbs apart I also need to check my right float & valve as the right carb seemingly decided to overflow while riding causing a bad burble on that cylinder as I was heading for home. Once parked in the driveway the overflow dribbled a little, which is a new issue. The carbs were just disassembled and ultrasonic cleaned a few days so the issue is strange, although I did note some unusual discoloration inside that valve seat even though it looked smooth and clean.
 
And I need to fill the rear brake system and bleed. That will include checking the rear caliper that may need a cleaning and inspection as it's been a while since I rebuilt it.

[SoCal250]

Howdy. I certainly wouldn't use those xs parts bin "specials"
Just my opinion. Plus I don't know what your end game is.
Thanks for showing your bike.

Hey Murray, haven't seen you around in a while.
Since this Daytona is far from stock, as it was was modified by its previous owner, I feel no obligation to retain "correct" OE bits on it. So I have some things planned for the refresh.

Despite repainting and rebuilding all the OE front brake components, I decided not to use them...

OK, here's the brake update I decided to do. This has been on my wish list for years. A few weeks ago I finally got around to making it happen with this recommissioning project. 
I don't have a good "BEFORE" picture as I didn't think of it until I already had the fender and brake master off.
BEFORE:


The disc was upgraded from 267mm to 298mm (3CW) from a 1990 Yamaha FJ1200. A custom spacer and SS bolts were added.
The front master was changed out for a 2018 Yamaha Zuma YW125 unit, which was refurbished with a new paint job, new lever, new cap, and new SS cap screws. The Zuma brake switch was modified to plug into the RD400 harness.
The OE single-piston caliper was changed out for a 4-piston (5DM) unit from a 5K-mile 2002 Yamaha YZFR6, and it was rebuilt with a new seal kit, pin, and EBC Double-H pads. The new caliper was mounted with a custom 0.500" bracket and new SS hardware.
In addition to the brake upgrade a RSW Racing fork brace was installed.











AFTER:

[Kawtriplefreak]

Beautiful work!!! I love big brakes and I cannot lie!!  

[Simmons1]

The big brake looks awesome, and probably works even better than it looks.

[85RZwade]

I love it! As MTV used to say: Too much is never enough!