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Check the cable to cap connection....even the so called sealed ones come loose....If you can twist the cap on the cable it is time for a new one. If it is a separate cap the cable will be almost certainly be copper cored...not used anymore...and can be trimmed and the cap refitted....hope this is it...so simple
 

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Ok I've been working on it this morning and now it will idle good but as soon as you give it trottle it pops loud out the exhaust as you release the trottle. If I let it sit and idle for a few min. both cylinders will rev up but if you do it again the back will stop hitting and it pops. If anyone can help me, call my cell at 423-645-1362. Thanks Aaron
 

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I was referring to the spark plug cap. What did you do to get it to idle better?

The problem seems to be only while under throttle and still could be electrical....vibration and or electrcial breakdown under load could be the problem. I would also be checking the compression on the rear cylinder along with the valve clearance....you may have a tight exhaust valve allowing unspent fuel into the exhaust...thus the loud detonation....also the timing may be sus on that cylinder. If possible change cables/coils and anything else over to see if the problem moves....one at a time of course. One other thing how are the fuel lines and any filters....sometimes even just a small re-route of a fuel line can cause major problems.

Good luck
 

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The fuel lines are good and a new filter. I did a leak down test on the rear cylinder and it shows 15% leakage witch I thought would be the rings bypassing. Would the carbs not being in sync cause this? I am going to sync them tomorrow and see. If not I will change the front and rear coils and see if it moves to the front cylinder.
 

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I think, at this point, it is a good idea to isolate the problem....many fool around with carbs only to find the problem was electrical all the time. Make sure any resisters within the ignition circuit are good....some makers used to put tons in to stop radio and tv signal interference. A fully charged battery is also a must with todays electrical systems being so sensitive to voltage drop. Make sure any sensors are connected...clean the terminals if needed. Check all the fuses for security and cleanliness all relays too...esp ones that are specific to the offending pot...some times just wiggling these can cause problems.

Good luck
 

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Today I sync the carbs and now it will idle fine and when you give it gas blue smoke comes out of the rear exhaust pipe like it's running rich. Do you have a wiring diagram for it so I know where to find the resisters?
 

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If there is blue smoke it indicates either a valve problem....burned valve seat/head and or worn bore/piston/rings. If this is the case and the smoke is fairly heavy then the problem is likely to be a consistantly fouling plug. You may be able to locate a wiring diagram on this site or a specific site for your model. Many online dealers have microfich parts lists that also have diagrams. You might find there are no resistors within the harness as many are now discrete and contained within electrical componants...esp as yours is an 04.

I would pull the offending plug and check it out....if it has wet oily deposits then it is mechanical and will need further examination and rectification. You might check your oil level before you go to all this trouble as someone may have seriously overfilled it. There should be an amount the engine holds in ml stamped or cast into the engine block/cover near the oil filler hole. If your bike has a dipstick on the plug simply check that.

Post what you find so I can give you the good or bad news.
 

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I adjusted the valves today and they were tight. Now the rear cylinder seems to be running good but now the front cylinder is poping and after trottle release it shots a flame out of the front exhaust pipe. The oil level is a little over full as well.
 

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Now the rear cylinder seems to be running good but now the front cylinder is poping and after trottle release it shots a flame out of the front exhaust pipe.
OK, well time to start over.......and I'm too lazy to go back and look..............

Are the pipes and airbox/filter in place and stock ?
If everything IS stock, then a slight adjustment of the low speed mix screw(s) might help.
If exhaust or intake mods have been made........running lean and popping kind of goes witht the territory.
Only jetting or going back stock are the likely fixes.
 

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Air box is stock and it has shotgun pipes with baffles. The carbs have been jetted up to 115 main jets.
Good luck.

I don't have any good suggestions for a bike that's been messed with like that except find a good independent (old) mechanic who knows carbs and how to use an exhaust gas analyzer (not many do anymore).

You could have an exhaust leak up by the headers........or you could have a fault in one carb, introduced by the amateur who probably didn't need jets in the first place.......or you could have a vacuum leak around one carb. It is possible that the popping you now have left is because it's too rich instead of too lean.

THIS is exactly why I will never knowingly buy a bike that's been messed with........by anybody but a fully qualified shop.
 

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I would go back to spec with the main jet...do a plug chop...not as accurate as it used to be... and then go from there. Stepping up the main jet changes the whole range of fuel mix and in most cases doesn't need to be done. I would suspect the previous owner was trying to get rid of exhaust pop/backfiring due to the pipes being less restrictibve and has overdone it. You will need to find out what the spec main size is to have any chance of fixing this problem.

Good luck
 

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Ok I replaced the jets for the stock 110's and it seems to be running some better but not real good. When I rev it and let off it is poping out both pipes and shooting flames out. I pulled the air shorkal off and covered 1/2 of the rear cylinder's air intake up and it seems to run good. What would make the rear cylinder be running so lean? Getting so tired of working on it.... HELP!
 

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Raise the needle in that cylinder...often the rear cylinder of a V twin is run slightly richer to compensate for less cooling air flow. Don't give up on it now you seem to be making headway. Try slightly larger mains. That rear carb might be running lean I would be checking all the filters and float level of that carb again...plus the idle circuit if the slight increase in mains doesn't do the trick.
 
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