Batavus - runs 10 minutes. Then dies.

Been through a lot with this bike. Runs like a dream for 10 minutes, then turns off like I hit the kill switch. Will intermittently start and run a few more minutes, then stall again. Repeat a few more times until I get all hot and frustrated.

Changed condensor, timed OK, plug isn't fouled.

Gas cap vent is working, exhaust port and muffler are not clogged.

I took the head off and cylinder, piston and crank in good shape, cylinder not scored, piston not scored, only mild carbon on the dome and piston top.

While I had it off I lapped the head and cylinder, got new (albeit homemade from Felpro paper gasket material) cylinder base gasket, no head gasket, reused same metal exhaust gasket.

Head is torqued to 11 ft. lbs, just like the manual says. No indication that it's leaking.

Carb is immaculate, running a #56 jet.

If left to sit for an hour it runs for another 10 minutes. I"m NOT losing spark when it stalls. (as evidenced by my inline spark tester.

Any ideas?

Re: Batavus - runs 10 minutes. Then dies.

It looks like you've covered most of the basics on this bike. My own experience with my Bat has been that this behavior suggests a gas flow problem. Whenever it runs for a few minutes and then stops, usually that means that the carb's bowl is filling and then getting depleted without refilling fast enough. That would account for why it starts up and then runs for a few minutes after you let it sit. Take a look at the brass screen inside the banjo nut going into the carb. I didn't even realize it was there until I stopped getting gas to the carb entirely due to crud blocking the screen completely. Next, obviously, examine the fuel line. If you have an inline fuel filter (which you should), clean that out or replace it. Also, at least on the HS50, the path of the fuel line is a little dicey, and there are a few spots where it's likely to get kinked. And then finally, check your petcock. Sometimes some of that rubber gasket inside the petcock can break off and get lodged in the valve. I'd rebuild it entirely and make sure you're getting steady flow. Let us know how it goes.


Re: Batavus - runs 10 minutes. Then dies.

I've had this bike for about 2 months now - owner claimed it had this same problem. 964 miles, so I've put about 30 on it in that time. One thing I'll admit to (and may very well be contributing) is a mistake I made when I did the head. When I took it off I noticed the head bolts were stripped and whoever did it before me managed to just catch the next thread, gave it 1/4 turn and that was it. So I ordered some new studs and bought a really cheap $20 click type torque wrench from discount. Bad move. I used it to torque my plugs in my car, to torque the plug in this batavus (with the head off), and to do my lugnuts. When it came time to put the new studs back in, I set it to 11 ft lbs, and started going to town in the cross pattern. It started to get a tiny bit difficult, then it snapped at the head end. I didn't realize it until I broke 3 studs. One of them in the crankcase. Lousy wrench had stopped clicking. So 3 studs later, a broken screw extractor, and a week of yelling at it, got the stud out, but unfortunately I noticed a hairline crack.

Its in the bottom right stud as you look at the sparkplug hole. It extends diagonally from top left to bottom right for 3-4 mm towards the screw hole, and also extends 2mm past the other side of the screw. I cannot find where this crack leads, and I'm assuming it just cracked the casting there. It doesn't seem to enter the crankcase or to the outside. I attempted to press jb weld (liquid kind) into the crack (it is VERY tiny and shallow) let it set up overnight, and hoped for the best. I ran a 6MM 1.0 pitch tap through all the holes with no resistance, and no metal, so I believe the threads are OK in the crankcase. Had all new bolts lock washers and flat washers, and put the studs in AOK. I torqued in an odd way since I don't have a wrnech. I tightened until the 10" ratchet could support a gallon of water (8.3lbs), approximating 6-7 ft lbs, then gave 1 more 1/4 turn, then an additional 1/8 turn. The cracked hole gave no indication of any problem, the stud went in fine and it torqued AOK.

Just some background. Does anyone think the crack could be contributing? I don't believe so. The bike ran just like this when I first got it, (i.e. hard to start, would stall, but once running, ran for 10 minutes.) Going over the ignition, replacing the condensor and timing, new plug, and cleaning the carb got it so before the stud incident it always started on the first kick, and ran for 10 minutes. Now although it did start on the 2nd kick after the head was back on, and ran like a dream for 10 minutes, it is now difficult to start. Sorry this is so long I'm just going over everything that was done, so I have an idea in my head.

I think your right on the fuel delivery. I did replace the fuel hose with black thick "fuel line" hose from Lowes. and I do have a clear fuel filter inline. There is fuel in it. I cannot find the brass screen in the banjo nut for the life of me, I had it apart twice now, so I think I may not have it.

I do have the white plastic hollow float, and Chris at MWH recommends that I replace that with the black solid float, due to a recall. It sounds good, and I'll be doing that in the near future. I think I'm also going to be getting a new top end of the float (top cover I think), and gasket and banjo and screen. I am intermittently dripping gas on the pavement and I think that might actually be flooding the engine, causing the problem. I think that might actually fix this. However, the dripping gas doesn't coincide with the stalling.

My GF watched it happen and with her limited engine knowledge said that she thought it was just overheating....

Re: Batavus - runs 10 minutes. Then dies.

I had this problem when I started my Puch Magnum up for the first time in two years. It turned out that the float wasn't floating correctly, letting too much gas into the bowl, then getting stuck in the up position, so no other gas could get in. Eventually, it worked itself loose again and now she runs perfectly. It took me like two or three days of this, though... so who knows? Clean the carb out again, and I'd buy some of the see-through lines from a store that sells dirtbikes/atv's/whatever, or from a place online, just so you could see the fuel flow. Good luck!

Re: Batavus - runs 10 minutes. Then dies.

the next time it stop's on you. do a plug chop right then. You could be running a little lean and over heating.

Re: Batavus - runs 10 minutes. Then dies.

mopedwhisperer /

You got to find out for sure if its fuel or gas next time it dies shoot starting fluid right away into the carb (get filter out of the way)if its starts, its starving for gas.Even though you have inline spark tester if that spark cap is faulty(highly unlikely) it won`t show it. Also I think that encarwi carb has a sneaky little vent hole that can get blocked .Does it die in ten minutes every time or 5min 1 time then 15min other time if it is very consistent it could be electrical/heat related/ could be coil (highly unlikely cuz its bosch) those ignitions are bullet proof. Banjo screen located in tip of hollow hex bolt that holds banjo to carb good luck ___hope this helps

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