Michael

Sorry for the late reply. The fuel filter is brand new so I don't think that is the problem. The float height on the other hand.. I have no idea about those. Had the carbs taken apart and cleaned, but it never occured to me, that the floats would have to be at a specefic height to be working optimal. Guess I'll take it apart again and take a look. Can you people recommend a height to set them in?

Does the XS 400 actually have a tank breather and where would it be? I have't stumbled across it so far.. :/ I got a fuel filter on the bike, would it have any effect?

Thanks for all the replies, will definitely check out the float height. Never thought about that to be honest But.. How would the float height have anything to do with the drop in fuel to the carbs? Isn't the float height a standard height where the fuel isn't flooding the carbs when turned off? Just me being a newbie, sorry But yeah, when you think about it, it does kind of make sense. If I keep the throttle maxed out for a while, it will eventually suck the carbs dry if the fuel is running slower to the carbs than the engine is using. And therefore I would have to let go of the revs. Will go check it out. By the way, I have stock airboxes and filters but a homemade exhaust system with less restriction than normal system has I guess. Just to get that clear. Pics of the bike with the custom exhaust link

Hey As written in the topic description, my XS400 looses enginepower after having driven around 110-120 km/h (around 75mp/h) for 20-30 seconds. The machine has fine power and runs great until it has run for 30 seconds, then I need to lower the speed of the bike because it looses all it's power. It feels like the bike isn't igniting in every rpm and therefore loosing power, just a thought, don't know if it's possible After having let go of the gas and the speed drops til like 80-90 km/h it runs fine again. Any ideas? Would be kind of useful to be able to run those speeds on the highway

Wonder why it didn't show I'm from Denmark? Anyways, I figured it out! I think it was a failure from my side. I must have been confused with the colouring of my own wiring harness and the Honda's regulators different colours. So, after studying the thing a little harder, and switching around on the connections, it works! Now I can finally go out and cruise on my bike without fearing the loss of power! ^^ But.. The regulator switches off at 16,2v which means it is like 1,7v above the 14,5v which should have been the max value. Does it matter? Or should I try to see if the thing is adjustable?

If I can't find one of those old regulators with 3 legs, is it possible to use one of the new ones with 4 legs? And then just like using 3 of the 4 legs? Like this one. Because these new ones are easy to find and cheap.

Apparently the Honda CB 400/4 can use it, but maybe it also uses a permanent magnet type of alternator? I'll take a look at my connections and also see if it's possible to find another regulator for testing purposes.

I have been having problems getting my bike to charge. After riding it for a while, the flasher suddenly didn't work and afterwards I had to drive without lights home. I checked the battery with a voltmeter and it said 12v. Starting the bike up the voltage didn't change at all, even at 3-4.000 rpm, no change in the voltage across the battery terminals. Things I've done: Checked the voltage regulator, which seems to come from a Honda. I checked the regulator with an ohmmeter and it gave following results: Between Earth and Lights (I) - 36.6 ohm. Between Earth and Field coil - 36.6 ohm. Field coil and lights - 0 ohm. NE0 said that his regulator had a value of 100 ohm between E-I and E-F but 0 at the F-I. I've also done a practical test of the regulator by putting some voltage in via a powersupply to see where the regulator "switches off". At 16.2v the regulator said a little click and it went to around 0.3 mV. So I guess that it works? I've had the alternator opened and visually checked it. Everything seemed fine inside - no loose wires and such. And according to the service manuel, I also checked the ohm between the white wires coming from the alternator. These values matched fine, 0.7 according to the manual and that is also the values that I got. The field coil also gave the right ohm values. The rectifier is another component I tested. I used one of those testers that "beep" when they get connection. And everything seemed fine. The tester only "beeped" when the current was going from the white and negative leads to the positive. It didn't say anything when going the other way. So I guess this is working. So what now? Is it possible to, for example, put 12v from an external battery to the field coil, use the kickstarter and measure a voltage going out of the rectifier? I feel kind of lost here The wires seem to have connection all the way around, no broken connections inside the wires as the tester from above beeped at all the connections I tested.

Ah.. But still, even though the budget wasn't a problem the bike you've made is still nice

Hmm.. So you'd just leave the pilot jet as it is and replace the main jet? Because when running with no real muffler in the exhuast, the gasses will flow a lot more freely and it would need a bigger main jet, right? And maybe raise the needle a tad for the mid-range point. Got it, will try that out. But will first have to identify the mains I have in the bike at this moment.

Almost forgot, when changing to straight pipes with lollipops, what is the common amount of jets to go up? Isn't it like 2 up in main- and pilotjet? And if I wanted to run pods at the same time, like 3 up in the jets instead of 2?

Heh okay. Well, I also kinda based my idea on an exhaust from my Yamaha FS1 2-stroke moped which had an illegal (where I live) exhaust which of course made it go faster. But after having consulted my father (which kind of owns this place), he just wants me to get the bike done so it doesn't use up all his space. So I've just, as you said, hooked on some pipes, straight through, and will fit some lollipops. We'll then see how that turns out..

Very nice build, if only I could make something half as good I would be in a good position

My stock exhausts are in a pretty bad shape. They both have holes in them and exhaust gasses are leaking out from them. So I was wondering, it is possible to make your own exhaust? I've got this idea so far: Would this be any good? Would it give enough backpressure, like the original exhaust pipes? In between the outher and inner pipe I would put some steel wool or something to dampen it. I'm open for ideas, as I think a straight pipe wouldn't be to good. (Makes to much noise when I have to use it for school every morning )

Aha, that cleared up the questions about the letters. I kind of figured out that E was for earth,, but had no idea with the F. My best guess for I was indicators - as in lights and such But it was better to be sure than just go for a guess when people know this kind of stuff