Weak engine due to lack of air

Post by **DARIVS** » Thu Jul 15, 2010 11:12 pm

Hello fellows,

I have a DKW NZ 350/1. I noticed that even after new piston rings were installed, the engine responds better when the throttle is increased and there is more power when the Wirbelluftreiniger (air cleaner) is taken off the carburator. It's as if the engine was bogging down due to lack of air, especially at high speed. Since there is no adjustment to let in more air, what do you suppose the problem is? The compression is excellent! There are no blockages in the air cleaner. Was the air cleaner known for causing resistance to air flow as an expense for ensuring that the air is clean? It seems to be running too rich when using the air cleaner. I can only get 70 kph at maximum speed.

I have Polish reproduction mufflers on the exhaust. Could this be contributing somehow to the weak engine when combined with the air cleaner? I know that gas flow in these engines is a complex thing.

Lolo · Post by **Lolo** » Fri Jul 16, 2010 9:34 am

Hello Darivs,

I have the same probleme. If you want to walk with the air cleaner, you have to change parts of your carburator. See on the DKWNZ website.

http://www.dkw-nz.net/cms/upload/img_pd ... r_2116.pdf

If someone know where to buy these parts to change the carburator, let me know.
Lolo.

Post by **pararigger** » Fri Jul 16, 2010 7:44 pm

Just got back from a ride with my NZ. Same problem.
After I changed from the Nassluftfilter to the Wirbelluftfilter it seems that it´s not running as fast as before.
90 km/h was no problem before, but now 75 - 80 km/h only.
Of course I changed the Carb needels.

Post by **DARIVS** » Fri Jul 16, 2010 10:17 pm

Guys, we need to find some 350-1 carb needles and ports. If I can find information on the dimensions of the parts, maybe I can have a bunch custom made for us. What do you think?

Lolo · Post by **Lolo** » Sat Jul 17, 2010 10:24 am

You can have the dimension on the Letter 2116 on the DKW website.
If you can find it, it's ok for me.
Lolo.

Post by **thomas591** » Wed Jul 21, 2010 12:15 pm

Folks,

check the download section theire is, may I say since few years

, the lists of the different jettings for the bikes with or without cyclone filter. All jets and needles are available from Fakk-Tilmans...check the "vedndors"-section.

Best regards

Thomas

Post by **DARIVS** » Wed Jul 21, 2010 3:09 pm

Thanks Thomas!

What does the "85" mean for the main jet? Does it mean 0,85mm size or 85cc flowrate?

Post by **thomas591** » Wed Jul 21, 2010 7:43 pm

If I remember correctly it means 0,85mm.

regards

Thomas

Post by **Frank** » Thu Jul 22, 2010 7:39 pm

According to "DKW Lehrmittel_Band 2 Vergaser und zündeinstullungen" the number on the AMAL mainjet means the fuel amount (cubic centimetres/min) of the jet, not the diameter, so it can be a bit hard to measure.

Best regards: Frank

Post by **DARIVS** » Thu Jul 22, 2010 11:21 pm

I wrote to Faak-Tillmans in German and English and asked ti buy the main and air jets and needle, but have not heard back from them. Their website does not allow purchases from the United States of America, only Europe. Thomas, if you purchase the parts I need from Tillmans, could I buy them through you ?

Post by **DARIVS** » Sun Jul 25, 2010 8:13 pm

Has ANYONE had success getting Faak-Tillmans to respond to email? I need to buy parts from them and their website does not allow purchases from America. If these fellows do not send items to the USA, then maybe I can pay one of the Germans on this forum to purchase parts and send them to USA. I need carburetor air and main jets correctly sized for the Bing 2/24 using the cyclone air cleaner.

Post by **thomas591** » Mon Jul 26, 2010 9:04 pm

youve got a PM

Post by **DARIVS** » Tue Jul 27, 2010 1:03 am

Thanks Thomas!

Post by **DARIVS** » Fri Jul 30, 2010 12:10 am

You guys are going to laugh at me for this.

I took the carburetor apart and found that all the jets and the needle were the correct type for use with the cyclone air cleaner on an NZ 350/1. The reason why the engine was starving for air was my fault. I was using the choke (air control) BACKWARDS, and starving the engine of air. I had the choke set for "fully open" when in fact, it was fully closed! Yes, I am new to motorcycles. This is my second motorcycle and I have a lot to learn. At least I was smart enough to take the carburetor apart and finally learn what the parts do. I ran the motorcycle for 80 km today, and it ran with more power going up hills. It ran at 88 kph downhill and 79-82 on level ground. So, the problem is solved.

I still want to buy the spare carburetor parts from Faak-Tillmans through Thomas. You can never have enough spare parts!