PROJECT DOKE

[TomcatMJ]

The following schematic of the Carbs shoudl help checking for restrictions inside the Carbs as the FZR 400 A (US-Model) has got the same Carbs as the first generation 1WG:

Source: http://www.cmsnl.com/yamaha-fzr400a-199 ... ml#results

In the aftermarket power-restrictionsets here in Europe which were used to reduce the Power to 34 PS /25 kW (used for drivers with restricted Licence) they used restrictorplates inside the rubber Joints between the Carbs and the Cylinderhead and additional Restrictors at either the Carbs Throttlecablemechanics or in the Carbs themselves to restrict the Action-Range of the Needles inside the Carbs (in german called "Gasschieberanschläge").

[venari]

Out of the 16 screws on the four carb bowls I managed to unscrew 6 without stripping the heads... I even went out and bought a whole new set of screwdrivers so I could make sure I had exactly the right driver for the screws...

In better news I did manage to get into one bowl and I was actually quite surprised to find it pretty clean with only a little brown gunk so I think I caught it early. The jets were a bit stuffed up but not fully blocked on this carb.

What is the best next step for getting into the rest of the carb bowls? I gather this is quite a common problem?!?

[venari]

http://www.fzrarchives.com/ipb/index.ph ... opic=56915

Found this useful thread on the archives site.

What do you think of the state of that carb bowl? I think it looks pretty good and am not fully convinced the gunk is the issue...

[TomcatMJ]

Maybe it (the dried fuelcomponents which sometimes behave like resin) stucks inside the jets...just pick in the jets with a nylon-line to check if theres something in which shouldn´t stuck in there

[venari]

Today I cleaned the carbs.

The best solution for getting those brass screws out was using a pair of mole grips to start them off. They aren't in tight, the heads just strip too easily. If you are trying this at home I STRONGLY recommend that you take off the back bracket and get ALL of the screws loosened off with mole grips before you get within a mile of them with a screwdriver!!! Unfortunately, if you are reading this it probably means you've just stripped them and are looking for solutions like me.

Click on the images below to see full size.

TROUBLESOME SCREWS - USE MOLE GRIPS INSTEAD OF DOING THIS!!!


ALL SCREWS OUT & READY TO GO


DIRTY CARB VIEW


DIRTY JETS


DIRTY VS CLEAN



DIRTY FLOATS


RECONSTRUCTED CLEAN


MARKINGS

[venari]

I find it intriguing that the outside carbs seem to have a different main jet to the inside ones...

Is this a clue that someone has perhaps had pod filters fitted in the past and re-jetted them for this or is it quite common practice even with an airbox?

I know the exhaust is non-standard but to be honest I would be surprised if the previous owner had known he needed to re-jet it...

My jets are currently:
87.5 - 85 - 85 - 87.5

[venari]

In the aftermarket power-restrictionsets here in Europe which were used to reduce the Power to 34 PS /25 kW (used for drivers with restricted Licence) they used restrictorplates inside the rubber Joints between the Carbs and the Cylinderhead and additional Restrictors at either the Carbs Throttlecablemechanics or in the Carbs themselves to restrict the Action-Range of the Needles inside the Carbs (in german called "Gasschieberanschläge").

Danke TomcatMJ!
This was really useful and helped me check that my carbs were unrestricted! Looks like a previous owner has already taken care of that.

Youre in the UK so give B and C express a call they'll sort you out. Tell them you want a rear sprocket to give a bit of acceleration and they'll factor that in for you too.

Thanks for the tip Evilchicken0!

The front sprocket is part number 289-525-15 and costs...

The rear sprocket will have to be specially machined and then anodised. This will take 2 to 3 weeks. The cost of the 525 x 46 tooth blank, machining and anodising is...

The chain is a 525MG-110 and costs...

[TomcatMJ]

Hm,according to the service manual a 3BF and a 3FH should have all Mainjets 87.5 (its some time ago i opened the carbs last time,but if i´m not missremembering thats true)...maybe the inner jets are changed due to an aftermarket-exhaust...at the FZR 1000 the inner Jets are also different sized due to cooling-effects with richer mixtueres which might compensate the amount of heat to the inner cylinders which are out or the little cooling direct airstream from the sides...and for unlocking the Power of the FZR 1000 (if its restricted to 72 kW and should be opened to 107 kW) these Jets have to be placed to the outer cylinders and the inner ones need rejetting, too, and also the rubber-joints between carbs and cylinderheads have to be changed to unresticted ones and at least a little rewiring would be needed.
So i guess its hard to say if your Bike is really rejetted or if thats still from factorystate....how many kW or HP does your 1WG have in the Papers? The 3BF with same jets everywhere is named 47 kW / 64 PS (=~HP) in the Papers, perhaps this might be one of the slight differences between the US-Models and the japanese ones

[venari]

Re; Your pic.
You need to remove the fuel tap, rinse the tank and fuel tap filters.
See the very fine sludge.dust on the magnet....that passes through the filters and settles in the float bowls....a certain amount will be caught in the large inline filter you are replacing but more by the process of sedimentation than filtration.

Just a quick note on this:
I emptied out the tank and removed the old main filter ready to fit the new one. All I need to do now is "rinse the tank".

After a quick google I found that most people with this problem are dealing with a fairly severe rust invasion (unlike my small quantity of fine sludge) and elect to tackle the problem using chemicals, ball-bearings and water as part of multi-phased attack over a number of days...

I am planning to literally 'rinse' the tank out with water.

I will remove the petcock in order to get as much of the sludge out as possible but I currently have no plans to attempt to treat the source of the rust in the tank and therefore it is reasonably likely that I will need to do this whole process again if I choose to leave the bike standing for some time in the future.

I may well be creating extra work for myself by doing this BUT I am still not entirely convinced that my starting problem relates to this sludge as the carbs seemed pretty clean when I opened them up!

[venari]

How many kW or HP does your 1WG have in the Papers? The 3BF with same jets everywhere is named 47 kW / 64 PS (=~HP) in the Papers, perhaps this might be one of the slight differences between the US-Models and the japanese ones

Max Power
59 hp / 44 kW @ 12000 rpm

[TomcatMJ]

How many kW or HP does your 1WG have in the Papers? The 3BF with same jets everywhere is named 47 kW / 64 PS (=~HP) in the Papers, perhaps this might be one of the slight differences between the US-Models and the japanese ones

Max Power
59 hp / 44 kW @ 12000 rpm

Seems to be an argument fro a difference as my actual registred 3BF states 47 kW / 64 PS @ 10000 rpm and a Topspeed of 207 km/h (between 128 and 129 mph) with 150/60 BT090pro Reartire...the actual unregistred second with 140/70 BT45r Reartire names 200 km/h (between 124 and 125 mph) in the papers with also 47 kW @ 10000 rpm.. and as neraly every motorpart is interchangable between first generations 1WG and the 3BF and also the Carbs and rubberjoints themselves, the difference should obviously be in the jetting ..maybe you will get a bit more power with the 3BF jetting if also the ignitiondiagrams are the same and the TCI would be directly interchangable

[willandrip]

Good write up;

The float bowl screw heads get mangled because all X head screws on Japanese motorcycles are JIS standard fit
(denoted on an undamaged screw by a dot indent on the head thus x.) a Phillips screwdriver does not fit correctly unless modified. It is common on float bowls....a impact driver used carefully is recommended as is replacement with Allen (cap) screws.

Your pic ...DIRTY FLOATS ; shows a good example of the scale that is deposited as the fuel has evaporated over time and
you can imagine how easily it blocks the very fine jets.

Your main jets are the correct sizes.
The effect is for emissions as well as cooling.

Rinse out the tank with petrol....save the fuel and allow to settle, then filter it and discard the sediment.
Use water if you can dry the tank thoroughly internally.

If you clean the system thoroughly (even if not convinced it is problematic) then it totally eliminates it from future
diagnostics and is very easy.

Judging from the scale on the plastic float ...the jets would have had much more deposits and likely have been the problem.

You see now why 520 was recommended over 525.....520 sprockets are available off the shelf.

Good job on the carb cleaning .

[TomcatMJ]

525 Sprockets are also available directly...
Frontsprockets: https://www.mykettenkit.de/Ritzel/525-58-x-516/
Rearsprockets: https://www.mykettenkit.de/Kettenraeder/525-58-x-516/
Chains: https://www.mykettenkit.de/DID-Ketten/525-58-x-516/

The only disadvantage is that you will have to know what sprocketzsizes(important to check the inner Diameter also) and chainlength you want as the ready prepared Chainkits in this catalogue start up with the 3TJ/4DX Models
But as they state the sprockets manufacturers i guess its also available somewhere in your neighbourhood when you know what to order (and therefore you can use this catalogue where i linked to to get an overview about the directly available sprocketsizes)

[venari]

As you know, whilst I have been working on the starting issues I have been looking at some other essential work the bike needs.

When I first took the bike out for a short ride it started running really rough and the revs wouldn't drop. It eventually conked out and I walked it home. It wasn't until I got home that I realised the grip had worked it's way down the throttle body and onto the bar end. I slid the grip back up the bar and it started straight away. So, I've been planning to replace the grips.

I bought these the other day and they arrived this week:
http://www.ebay.co.uk/itm/130769448261? ... EBIDX%3AIT

But when it came to fitting them I was presented with a bit of a problem. The throttle side bar end has no socket in it for an Allen key whilst the clutch side does!


So I assumed that it must still screw out and I went and found some of my most commonly used tools...


But it was to no avail. Now I'm wondering if it is possible to remove the throttle assembly from the other end of the clip on somehow? Has anyone else found this to be an issue? Should I just keep hitting it?

Anyway, in frustration I moved on to the next job. Removing the radiator to allow easier access to the spark plugs for a switcheroo... I had heard that you can just remove the side mounts and let it hang there and get good access to the plugs, rather than having to empty the rad itself so that's what I tried next.


It would appear that I don't have enough slack in the rad pipes for the top rubber to clear the mount so I'm going to have to drain the rad anyway.

Quick question: Can anyone explain the purpose of the rad water tank at the back of the bike (under the fairing). Is this an overflow or should it be kept full? It looks lower than the top of the rad so I can't see what it achieves...

[venari]

Rinse out the tank with petrol....save the fuel and allow to settle, then filter it and discard the sediment.
Use water if you can dry the tank thoroughly internally.

If you clean the system thoroughly (even if not convinced it is problematic) then it totally eliminates it from future
diagnostics and is very easy.

Thanks!

The JIS thing explains why I couldn't find the right head in my screwdriver collection.

I will clean the tank thoroughly with clean fuel and with a new filter fitted and freshly cleaned carbs I'm hoping we'll be on to a winner!