PROJECT DOKE

[venari]

Thanks guys,

It has a 525 fitted currently and it looks about right for the bike so I think I'll stick with that.

I get a bit confused with gearing ratios but the 14/47 sounds quite a significant shift from the original. Is that a lower gearing (higher rpm)???

From the research I've done a reasonable step would be something like 15/44, I've heard some people notice the chain rubbing when you go below 15T at the front, any experience of this.

I have to say that 14/47 does sound appealing as I want the bike to feel as nimble as possible.

[willandrip]

Hunt for a page called "Gearing Commander".

I also use this ; http://www.sprocketcalculator.com/.

You can choose whatever size you wish from either "calculator".

525 is overkill on a 400 unless you are getting the components for peanuts.
Remember when you go up chain size you also up the rotating mass weight.

I do not go below 15 tooth on any chain....the tighter radius tortures the chain.

[Evilchicken0]

I think 525 is far to big, remember this is semi sprung mass. As for sprockets, if you go to a standard or two up on the back you'll be about right for basic road. These bikes don't have a high top gear and it's easy to end up revving the tits of it and going nowhere

[venari]

Thanks for the advice guys, I yield to your greater knowledge. I'll go back to standard + 2t on the rear.

It's all trivial until I've got it running again anyway.

Still waiting for a new filter to arrive and replacement plugs.

I'm going to plug the electrical connection for the pump back in next time and then switch the ignition on to see if it is actually pushing the fuel through. The tank is currently only about 1/4 full as I wasn't sure how old the fuel in the tank was when I bought the bike so that could still be my problem.

[venari]

Results of experiment:



As previously mentioned, filters seem to be OK although I have ordered a new main filter.

[venari]

Popped into my local bike parts shop today to pick up new sprockets and chains.

I asked for the following:
428 Chain
19T Front Sprocket
57T Rear Sprocket

They asked what bike it was for and proceeded to tell me that these sprockets wouldn't fit as the bike was designed for a 525 chain (which can easily be converted to a 520 chain) but that the sprockets for a 428 chain would not fit on a bike designed for a 525 chain. They said that combination also wouldnt work and that if I wanted more acceleration I should drop a few teeth on the rear rather than increase it.

All this has lead to myself (someone who openly admits to not quite understanding the whole 'gearing' concept) to become incredibly confused!

Arggghhhhh!!!!!!!!!

[TomcatMJ]

The combination of 19/5 with a 428 chain (130 links) is officially stated in the Service Manual of the US-FZR 400 /types 3BF and 3FH,based on the first generation 1WG) for Modelyears 1988,1989 and 1990. Nowhere inside the official Service Manual (wich is still available as an official reprint at http://www.yamahapubs.com ) is another chain than a 428 even mentioned, so using a 520 or 525 chain is at least for the 3BF and 3FH obviously work of some Aftermarket-Dealers, not officially from Yamaha.
By the way, if you drop some teeth at the rear Sprocket you don't get more Acceleration but more Topspeed for the price of a bit Acceleration...but you can change the front Sprocket to less teeth,then you will get more Acceleration for the price of less Topspeed. Just think about the different gears of a bicycle's transmission and you will see it soon ...

[willandrip]

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.


There are two std. sprocket combinations on pre 3TJ 400 FZRs.
Ratio = how many turns of the front sprocket to turn the rear sprocket once.

Early... 15/41 which is a 2.73 to 1 ratio

They changed on the 3EN1 to 19/55 which is a 2.89 to 1 ratio. which gives 5.9% less torque (acceleration) and the same percentage more of theoretical top speed .

The Genesis,....I am sure had a 428 chain although I have no parts book to confirm.
The next model. SP2 tk had a 525 chain....which is overkill.(This was principally built for a race series in
Japan...apparently)
The next ,3EN1 is back to 428 as is the later and last model 3EN2 before the 3TJs were built.

Use the links I gave for the online calculator and a notebook.
Input the std. sprocket sizes and enter your intended new sizes....compare the ratios and increases/decreases in torque
and top speed. 10% either way would be the max in my opinion.
A smaller front sprocket spins faster....= more acceleration but runs out of top speed.
A larger front sprocket spins slower ....= more top speed but slower acceleration.

A larger rear sprocket is easier to drive giving faster acceleration but runs out of top speed.
A smaller rear sprocket is harder to turn giving less acceleration but has a higher top speed.

In the UK....owners use 428....the savvy ones convert to 520.

Ensure you have a good genuine lockwasher fitted on the gearbox shaft when you fit the new c/s set.

I use AR racing services for c/s parts.
If you Email Kayla (a forum member on here too) @ Projection Components , she will discuss your exact requirements and is very knowledgeable on your model.
Others recommend B&C.

Postage is extra to what you buy locally but you get better quality components at a much reduced rate which makes the P+P irrelevant.
http://www.projection-components.co.uk/
http://www.arracing.co.uk/

[Evilchicken0]

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.

[TomcatMJ]

http://www.fzr-forum.de/files/geardata.zip <-This software wil be useful for precalculation of the Sprockets and Chainlenght and will give you theoretical diagrams about Speed according to the rpm at the given trasnlations...and so an idea about Acceleration+Topspeed when you have a look at the angle of the given diagramlines...
One thing you will need for these calculations are the values of the gears transmissionratios and for comparision with alternative sprocketsizes the actual settings for your chain/sprockets combination (and then it will also show the needed chainlength for the wanted sprocketcombination)..

Edit:By the way:This Windowssoftware will also work in Linux when using wine

[venari]

Thanks for the homework guys!

I played the sunset game again tonight - trying to get the bike to bits then back together in the half hour or so of light I have between getting home from work and it being too dark to see the little bolts.

My mission was to work out what is currently fitted to the bike:
1. The chain is a 5## (not sure how to check width, will have to google it)
2. The chain is rusted and there are several seized links
3. The chain has 104 links
4. The front sprocket is floating and has 15 teeth
5. The rear sprocket is very sharp and has 45 teeth

Whilst I had it all apart I took some photos:

[TomcatMJ]

Source: https://www.tourenfahrer.de/motorrad-te ... er-ketten/

This might help for checking the existing Chaintype of your Bike

Edit:Usually it should be enough to clean at least some chainlinks properly as the chaintype is usually engraved on every link if its a chain made by a common known brand like D.I.D or Enuma ....

[Evilchicken0]

Plenty of life left in the front sprocket, yours is only just run in



Theres no point in in busting your balls trying find out what you have on the bike, you're going to throw it all away anyway. Just talk to B and C tell them the bike and you want slightly better acceleration by 2 teeth, they'll do the rest.

[venari]

I found this really useful guide to removing the carbs on the carb thread on fzrarchives:
http://s93420228.onlinehome.us/fzr/carbs/

Just about managed to yank the carbs off after loosening the boots, they were stuck solid so I'm hoping this means they've not been fettled with. Certainly at first glance they look good.

Where were the limitors on these bikes? Just want to check mine whilst the carbs are out.

Now the carbs are in the house and out of the rain I can work on them in the evenings this week

I've left a message with B&C, hopefully they will get back to me on Monday and I can get the chain & sprockets ordered.

Next jobs:
1. Clear out rust from fuel tank (and treat?)
2. Replace filter (8mm or 10mm???)
3. Clean carbs
4. Remove radiator to replace plugs (and HT leads???)
5. Check valve clearances
6. Paint frame struts
7. Replace struts (engine mounts?)
8. Replace lock set
9. Paint fairings
10. Put back together & cross fingers

Oh and 11. Go out for a ride!!!!!!!!! (At this rate, at least it will be sunny...)

[Evilchicken0]

That model doesn't have a jap market restriction. The restriction came in at 1988 on the 3en1 it's a speed restriction and is in the CDI / Speedo.