Can I ride without a turbo?

I'm focusing on cleaning carbs for my XJ650 Seca Turbo. They were VERY dirty. Bike ran but very rough. It has a bypass valve installed temporarily from previous owner.

So as I get ready to install the carbs, is my tuning going to be way off as I try to get it to idle with no turbo? It wouldn't make a difference at idle, no? I figured I'd get the bike to idle first before going out and pouring money into a turbo.

 

The question you posted is “can I ride without a turbo” - I would say no, your fuelling will be way off.
Can you set the idle without the turbo - I would say yes, but the settings will be way off due to the changes upstream of the carbs. Don’t see what it achieves really?

 

Considering the way Yamaha designed the bike I must respectfully disagree with @Minimutly. The bike is designed to run naturally aspirated until it begins to build boost from the turbo. The boost pressurizes the chamber before the carburetors via flapper valve and then blows through the carbs. Until you build enough boost to close the valve the carbs are drawing air through the chamber so your tuning remains the same. Turbos use specially built Mikuni carburetors rather than the Hitachis used on other XJ's.
If you are rebuilding your carburetors it is worth it to spend the extra money to get Mikuni float valves rather than the aftermarket pieces. The aftermarket float valves work "okay" but the fit is just enough different that if the floats adjustments are not quite right it is harder to get right. Specifically in the Turbo I had the tab that limits how far the float droops open. I had 2 that allowed the floats to hang too low and when they closed the valve was not square in the bore and did not seal.
Good Luck!

 

Is that disagreeing with riding it or setting it to idle? I was pointedly separating the two, and stand by what I said, the fuelling will be way off at anything but idle, and even at idle the settings will be off, but you should get a decent idle.
Sorry, I thought I’d been clear.

 

My opinion is it will make little difference whether riding or idling. They operate as naturally aspirated motors until they begin to build boost. The boost begins to build at 5500 to 6000 rpm. Until that time the turbo is just in the way of the exhaust. Until boost closes the flapper valve they are just drawing in air through the airbox like any other XJ 650, albeit one with lower compression. "Normal" riding at around town RPM there will be no difference. If pushing above the RPM where boost would be building it will just be less responsive.

 

+1 You can ride all day and never use the boost provided by the turbo. One of my favorite bikes!

 

Well, you might be right...

 

Obviously you can ride motorcycle without turbo but it will trouble you more. As it will cause oil leakage and poor engine functioning due to engine oil blockage. Turbo speeds up motorcycles that's why its common in sports bikes than roads bikes.

 

Actually yes, if you run the Seca Turbo with the turbo unit physically removed you need to deal with the oil lines to/from the turbo.
If you're just in the garage and trying to idle the motor, just run the oil line previously going to the turbo into a catch pan.
Connect the scavenge line (from the turbo to the scavenge pump) to a fresh supply of oil.

Note with the turbo unit removed it will be breathing unfiltered air. This shouldn't have much affect on the idle.

What exactly was bypassed?