Skip to main content

Misfire- The lady that interrupts... ????

"Running the bike 2 up the other day at speed, she had a hesitation with a small loss of power. I backed off the throttle and engine feels fine. Could this have been a misfire? Caused my the Omega system?..." Was the Question I asked over at the BOXERWORKS forums.

"Sounds more like fuel starvation to me ... electronics are stupid, they calculate from input rpm whether in 3rd 4th or 5th gear. Check fuel flow, float bowel level, both petcocks on under load etc......"

"Maybe your petcock screens are clogged with "stuff" or your fuel lines need replacing. The magic chemicals being added to gasoline now is cabable of really making a mess of various older "rubber" parts......"

My reply .... "Carbs have never been overhauled in the time I have had the bike. 3 years. So will check these over and see what might need replacing.

135 main jet is standard according to owners manual for 32mm Bings. I have had 145s fitted and had put the 135s back in for fuel economy reasons. 145s suck fuel so quickly at speed.

I will also have to check the fuel cocks to see if they are getting clogged up.

The bike starts first go no probs. Comes of the choke no porbs and runs well. Will rev through the rev range in each gear with gusto. Just in top and slowly winding her out that she hits this hesitation.

Thanks guys."

The floats heights were checked. They are good. Fuel tank drained and lots of gunk found in one of the in fuel cock filters. This was on the inside of the mesh filters.

Found this plastic bullet type thing with 4 weighs built into it in the tank. WTF?

Turns out the previous owner had put this into the tank. Took some fishing around with a bit of bent wire to get it out. This is a Fitch Fuel Catalyst. 

The Fitch Fuel Catalyst Advantage

Increases Miles Per Gallon
Increases Horsepower & Torque
Quicker Throttle Response
Smoother Running Engine
Permanent Stabilizer for Off-Season Storage
Reduces or Eliminates Ping and Knock
Allows for a Lower Octane Fuel
One Time Application for the Life of the Engine
Good for 2 & 4 Stroke Engines

Yeah ok. I did not put it back in. 

So cleaned the the float bowls out and cleaned the fuel taps out. As I am putting the right hand throttle cable back on I stick my finger on some wire. Again WTF. I look down and the throttle cable is frayed not too far up from the nipple. I had suspected it was the right hand side that was playing up.

Looks like the frayed bits were catching and not allowing the right hand carb to open as far as the throttle grip was. This would explain the hesitation at the upper end of the bikes speed range.

I have had new throttle cables waiting to be fitted for about 12 months. They are now.

So new cables on and I have to balance the throttle cables. I have been shown to do this by ear. Yet I still can't get them right.

Yesterday. Huzzah!!!!!!!!!!!!! Took bike out to get warmed up. Set idle speed and idle mixture on side of road. Rode home. Put Carbmate on carbs.

One carb was so far out it was not funny. Tuned in the carbs. Took for ride. Rode very hard. Wow I love how she is now running. She feels the best in the whole time I have had her. Also got rid of the popping on over run.

Proves to me that I can not tune carbs by ear. I did this last week and really stuffed up the settings. Thankyou Carbmate.


Popular posts from this blog

Tuning 40mm BING CV carburetors for BMW motorcycles by ear.

Steve Doyle has put together this great and simple guide to tuning your Bing carbs. No need for expensive tuning equipment. So over to Steve...... Any feed back on this How To please email me and I will pass it onto Steve.

There are 3 common methods to syncing the carbs. They will all work
1. Shorting the plugs. and
2. Using a manometer of some sort. Carbtune, Twinmax or home made
3. Using your ears. No comprehensive articles that I could find..

In the spirit of learning to service and tune at home and after lots of reading, I decided that for me the "by ear" technique might be the most useful, as it doesn't require any special tools and can be performed anywhere. There is no risk of electrical damage to the bike or the one doing the adjusting.

It was very difficult to find a comprehensive description of the procedure, so using the combined kn…

Ride impression of the Yamaha MT-03.....

Yamaha have realeased their new 660 based single. The MT-03. See I so want one....MT-03 The bike can be had in Europe but not here in Aussie land. I have asked Yamaha Australia if they will bring them in. They said "No plans at this stage to introduce the MT03 in to Australia." To rub salt into the wounds, axxess, the forum admin guy at got to ride one. NOOOO!!! So unfair. He translated his ride impression into English for those of us who will not get to ride this. Thank you mate for doing this for us. So lets see what he has to say.....

Saturday 16 February I could try the Yamaha MT-03 at Gebben Motors. I could try a brand new red 2008 model. After a short instruction and a warning because of the new tires we were ready to go! The first thing I noticed was the enormous wide steer and the upright riding position It gave me a feeling of absolute control and power! The seat was quit hard but not uncomfortable at all.

Unless it was still freezing t…

The petite MZ...

I asked a question on the MZOG • MZ Owners Group if I should call my bike an MZ or a MuZ. I got some very informative replies. One reply was emailed to me with a link to Wikipedia MZ entry.

What really caught my eye on this webpage was this very petite MZ 125 4 stroke water cooled single.

This is what was said about this bike… “MZ currently manufactures a line of 125cc 4-stroke motorcycles using a new and powerful engine designed in-house. The current MZ 125 produces 15 crank-horsepower (11 kW) and almost 10 lbf·ft (14 N·m) of torque. It is a liquid-cooled pressure-lubricated dual-overhead-cam design with 4 valves, high-voltage electronic ignition and an 11000 rpm ignition cut-off. This is officially the most powerful 125cc 4-stroke engine mass-manufactured and has also proved highly reliable. This engine is used in 4 models of motorcycle, all of which share a common frame. The frame is a tube-steel backbone with the engine as a stressed bottom member. Changes in the suspension, facia, …