XS400 5th gear only

[Xaper]

Hi,

i'm riding xs 400 converted to bobber about 3 monthsand I have a few questions.
Achieved through me V-max speed is only ~ 120km/h, i got only 5 gears is it correct?

In pappers i got 16Y VIN so it's XS 400 Special
Made date is 1986.
Please help.

 

[Xaper]

Photo

 

[HoughMade]

Yes, I believe it was a 5 speed. Earlier models had the 6.
120 kph sounds low and like the engine isn't running as it should. My SOHC bike tops out over 130 kph, and I'm a pretty big guy. From the pic it looks like stock or nearly stock sized wheels and tires. Is the gearing stock? What rpm are you turning at top speed?

 

[16VGTIDave]

Maxim was 5 speed only. Top speed should be around 140 kph. With those exhaust pipes and pod filters, you will have great difficulty tuning the carburetors and will likely never see 140. Ask me how I know...

 

[Xaper]

it loosing ignition on hi rpm's
i don't have rpm meter so i can't tell you when it's happening

 

[16VGTIDave]

If what you say is correct, then the TCI module is possibly starting to fail. When mine was going bad, I had high RPM misfires. I thought it was problems with the carburetor jetting, until the TCI module failed completely and I replaced it. Be aware that there were different versions of the modules available in Germany. Some were for low power "learning" motorcycles. You don't want one of those!

I'm still saying that the pod filters and exhaust are going to cause problems. They do for everyone.

 

[Xaper]

So... What to do?

 

[HoughMade]

I think he's saying test the TCI and replace if necessary, and try to tune the carbs (after eliminating the ignition as an issue), but understand that with the intake and exhaust radically altered from stock, it will be hard to get it to run as well as a stock, tuned engine.

 

[Old Mose]

I'm certainly no expert but I do know that it will never run as well as it could without some mufflers to provide some back pressure. The fuel system simply wasn't designed to work that way. I know they aren't in keeping with the style but a complete Mac 2 into 1 system or something similar would be a good place to start.