My Sr400

[Spoonman]

So its not more powerfull, really?!

Going up from 34mm to 38mm it should make more power (in theory) however this is secondary to the reason for fitting and that is easier starting/smoother running (through-out out the rev range) and being able to use gasohol when benzine is not available and given I have halved the capacity of the fuel tank I expect this will be often.

[Spoonman]

Frame back from paint - the build begins.

Needs full assembly and then get it back to the wiring guy.... shakedown run is Pattaya to Baen Sean for the speed Festival on the 21st/22nd.

It has come A long way since I bought it 12 months ago.

[dave_boo]

Frame back from paint - the build begins.

Needs full assembly and then get it back to the wiring guy.... shakedown run is Pattaya to Baen Sean for the speed Festival on the 21st/22nd.

It has come A long way since I bought it 12 months ago.

Nice detail with the Yamaha tuning forks.

[OmegaRacer]

Nice!

What is the Speed Festival? Car racing? Any bikes there?

[Spoonman]

Car racing, we are running 2 pickup and 2 sedans. Me and my work mate who also has an SR always ride to the race meets.

[Spoonman]

New swing arm bearing's fitted and swing arm mounted and torqued.... another crossed of the "to do list".

[Spoonman]

Rear = done so time to turn her around.

[Spoonman]

Almost done, wiring and seat this week and if I can get a throttle cable should be riding it next weekend.

[Spoonman]

Provided I can stop the fuel tap from leaking she should be up and running today.

Edited December 21, 2013 by Spoonman

[brfsa2]

she looks beautiful... specially with that exhaust and black rims and tires.

The sound must be good too! please upload some videos

What a nice job...

[Wong!]

Lovely looking bike.

[BSJ]

It's come together really well. Maybe the best looking SR400 in Chonburi??? To be fair I haven't seen em all!

[Spoonman]

Thanks guys.

Sadly do to some unexpected issues I have not yet managed to fire it up, it'll get there though and then I can grab some decent pics to show ya's out in the daylight away from my tiny little workshop.

[Spoonman]

couple more pics. (<deleted> me what the white spots are, the fender looks like polished black glass normally).











.

[Spoonman]

[Wong!]

^ Missed a bit...

[Spoonman]

It's alive. temp fuel tap hits the engine but am stoked I was able to take it for a ride, been 4 months since I pulled it down.

Few small issues to fix.

1. Fuel Tap (new one being sent by Omega Racer)

2. Indicators do not flash (I have resistors on hand to install)

3. 1st gear hard to select (not sure what is going on here but I'll pull it down for a look)

4. Slight oil leak from oil filter cover (had some dodgy sealant on it, will clean).

[BSJ]

Looks pretty crazy! But in a good way. Is the tail/stop lamp up under the seat?

[moe666]

Good job, looks good

[Wong!]

I bet it goes well as it looks really light. Nice job.

[Spoonman]

.Well the electric gremlins have decided to move so the bike is sitting at the moment.

Multi meter tells me that both the HT Coil and CDI primary coil are dubious, bike is basically un-rideable above 3000rpm as it breaking down bad.

Got a new CDI/HT coil/Rectifier coming from the UK so hopefully that sorts it, if not it's gunna be an exxy re-wind of the stator that I cannot get done locally.

Anyways always one to tinker I found a set of bar risers locaaly for <deleted> all so given I was not comfortable with the riding position (straight bars) and the angle of the clutch cable entry I slapped em on. Feels a heap more comfy sitting in my shed making Brrm Brmm Brmm noises.



Also got bored at work today so did a quickie drawing and cut out a new Tacho mount.

[AllanB]

"HT Coil and CDI primary coil", I am not familiar with this arrangement, do many bikes have this setup? I have a 30 year old 400 V-twin Honda and have high rpm misfire problems, changed both HT coils and all 4 HT leads and plugs, but nothing makes any difference. Don't have the tacho working but would guess it happens about 5000rpm, under load.

Sorry this is a little off-topic but would appreciate any help.

[Spoonman]

"HT Coil and CDI primary coil", I am not familiar with this arrangement, do many bikes have this setup? I have a 30 year old 400 V-twin Honda and have high rpm misfire problems, changed both HT coils and all 4 HT leads and plugs, but nothing makes any difference. Don't have the tacho working but would guess it happens about 5000rpm, under load.

Sorry this is a little off-topic but would appreciate any help.

Sorry it should say low speed coil not CDI primary. it is part of the magneto that feeds the CDI. to fix I need to send the whole stator away to be rewound.

How bad is your miss fire ?, could it possibly be fuel related ?

[AllanB]

"HT Coil and CDI primary coil", I am not familiar with this arrangement, do many bikes have this setup? I have a 30 year old 400 V-twin Honda and have high rpm misfire problems, changed both HT coils and all 4 HT leads and plugs, but nothing makes any difference. Don't have the tacho working but would guess it happens about 5000rpm, under load.

Sorry this is a little off-topic but would appreciate any help.

Sorry it should say low speed coil not CDI primary. it is part of the magneto that feeds the CDI. to fix I need to send the whole stator away to be rewound.

How bad is your miss fire ?, could it possibly be fuel related ?

Not as bad as yours, the bike is driveable as the misfire is only noticeable under fairly hard acceleration. I "feel" it is linked to the hot start problem which occurs as follows:-

I ride the bike normally and after anything between 10 and 50km I sit at the lights, the rpm drops and it cuts out if I am not careful. When I try to restart, the engine cranks but will not fire at all, no matter what I do. If I wait for 2 minutes, the bike will start and then run, but at all times after that I need to be careful the engine doesn't stop..

So it could be fuel. To eliminate the unlikely possibility of vapour lock, yesterday I wrapped the (short) rubber fuel line in tin foil, as it runs along the top of the rear rocker cover and would be very difficult to re-route.

The engine temperature is absolutely normal, plugs a good colour, but I am not getting anywhere near the published 43bhp, which admittedly occurs at 9000rpm.

Otherwise the bike is fantastic...though I know of a SR400 that sounds that way too.

[Spoonman]

[paz]

Not as bad as yours, the bike is driveable as the misfire is only noticeable under fairly hard acceleration. I "feel" it is linked to the hot start problem which occurs as follows:-

I ride the bike normally and after anything between 10 and 50km I sit at the lights, the rpm drops and it cuts out if I am not careful. When I try to restart, the engine cranks but will not fire at all, no matter what I do. If I wait for 2 minutes, the bike will start and then run, but at all times after that I need to be careful the engine doesn't stop..

So it could be fuel. To eliminate the unlikely possibility of vapour lock, yesterday I wrapped the (short) rubber fuel line in tin foil, as it runs along the top of the rear rocker cover and would be very difficult to re-route.

The engine temperature is absolutely normal, plugs a good colour, but I am not getting anywhere near the published 43bhp, which admittedly occurs at 9000rpm.

Otherwise the bike is fantastic...though I know of a SR400 that sounds that way too.

Misfire under acceleration is most likely electric, as mentioned, HT coil or other ignition part. Check if HT coil is overheating.

Try reducing the spark plug gap of 1/10 mm and see if any difference.

Edited January 17, 2014 by paz

[AllanB]

Not as bad as yours, the bike is driveable as the misfire is only noticeable under fairly hard acceleration. I "feel" it is linked to the hot start problem which occurs as follows:-

I ride the bike normally and after anything between 10 and 50km I sit at the lights, the rpm drops and it cuts out if I am not careful. When I try to restart, the engine cranks but will not fire at all, no matter what I do. If I wait for 2 minutes, the bike will start and then run, but at all times after that I need to be careful the engine doesn't stop..

So it could be fuel. To eliminate the unlikely possibility of vapour lock, yesterday I wrapped the (short) rubber fuel line in tin foil, as it runs along the top of the rear rocker cover and would be very difficult to re-route.

The engine temperature is absolutely normal, plugs a good colour, but I am not getting anywhere near the published 43bhp, which admittedly occurs at 9000rpm.

Otherwise the bike is fantastic...though I know of a SR400 that sounds that way too.

Misfire under acceleration is most likely electric, as mentioned, HT coil or other ignition part. Check if HT coil is overheating.

Try reducing the spark plug gap of 1/10 mm and see if any difference.

I can scarcely believe this, I took the bike out around town this morning to see how it ran, prior to taking your advice by reducing the plug gap and....the damn thing is running perfectly.

The only thing I had done prior to the last run was to wrap the petrol feed pipe in tin foil to prevent a vapour-lock...and earlier added some some fuel system cleaner to my petrol.

Now it seems the problem has become intermittent. Don't I just love old bikes! ....**##*!sh?mf^^%£!!?

[paz]

Intermittent problem = electric cause. Old parts develop unreliable internal resistance, coils are especially prone to due to degratation of winding insulation, and more so when hot. Usually undetectable by any bench instrument.

[AllanB]

Intermittent problem = electric cause. Old parts develop unreliable internal resistance, coils are especially prone to due to degratation of winding insulation, and more so when hot. Usually undetectable by any bench instrument.

Went out and bought a DVM, but can get much of reading on any of the 5 coils I have, can you explain the test and expected readings?

Thanks

[BSJ]

Hi Al, are you measuring resistance, voltage or something else?

In years gone by I have experienced problems with bikes with external resistors in the circuit....but being a modern Honda maybe the resistor is in the coil, like so many others are today.