Loss of power/bogging down when in gear.

C

chrisbuckart

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Decided to take the bike for a spin today since the weather was nice, I fired her up and let her idol for 20 min. Been noticing some popping lately at idol as well as in gear throttling off. Left side I think. When I took off up my street instantly notice a decrease in power. I ride with no tacho so I have no idea what RPM's she was sitting at. The bike did pretty much the same thing in 2nd, 3rd, and 4th gear. Then died on me in 1st at the other end of my neighborhood. I was able to get her started easily several times but once put into gear and throttled she would die. Finally throttled her hard and got moving. I'm running a Pamco ignition, and Mikes XS ultimate high output coil that came with the kit. Before installing ignition I did the cam chain tension, valve lash, and timing in that order. All has been running fine, with the exception of what I think is a loose cam chain flapping intermittenly in the engine. The only thing I have done is I removed some old electrical plugs/wires from my harness that I haven't been using for months and wanted to delete them all together. And I followed them back to where they were spliced in and removed them. Test road after doing so and seemed okay then. That was last weekend. Things like flash cancel unit and reserve lighting unit have also been deleted. Also double checked fuses and electrical connections after having the problems.

Hope that's enough info to start the diagnostics, and thanks in advance everyone.
 
Periodical maintenance. Clean the carbs. In particulair the pilot jet/slow jet/idle circuit.
Yearly if not twice.
Anything red/brown flakey would be considered rust?
gggGary has suggested the black pepper looking stuff may be a deteriating fuel line.
The light brown crusty stuff that turns into whiteish powder is gas varnish?
 
Sounds like you are firing on one cylinder. It'll start up just fine but has an immediately noticeable lack in power.
 
weekendrider: Yes, this would be a good time to clean and rebuild the carbs. Daunting task for a newbie, but should make for a great learning experience.

retiredgentleman: I was just reading another thread on here about ditching the old fuses and replacing them with the automotive blade type fuse holders. Does anyone know of a well illustrated how-to of such a task?

drewfunk: How would I go about testing to confirm your theory of firing on one cylinder. Is this something a trained ear would listen for? Again, new to bikes so I have loads of beginner questions.

Thank you so much guys! Great help. My winter to-do list just multiplied.
 
I had the same problem recently, would run fine in neutral but would get progressively worse when under load to the point it would give up about a mile down the road, and a big part of the problem was that the foam on the original air filters was collapsing! I didn't realise what the problem was though until I tried washing the filters and they just disintegrated then.
 
essexboydave: Hey, thanks for the tip. Last summer I did pull the airfilters to clean and lubricate. Seemed to be in good shape as far as I could tell. Would be worth another inspection though. Been thinking about the switch to K&N pods, might just work that into the to do list as well. That would call for some changes in the jetting as well I believe.

XSLeo: Thanks for the carb guide. Will come in handy once Mine is sitting on the workbench.
 
First I would check the easiest and cheapest thing that would affect your problem. Pull the air filters and start the bike and take it for a run. From there check out fuel system and finally check out your electrical. Make sure the battery is fully charged, valves set and cam chain adjusted. Good luck.
 
Was looking over the bike today and noticed fuel had been leaking from the left side carb holder. I'm assuming this is another sign pointing to carbs. Another thing I should point out is that I'm no longer using the vacuum barbs on the original carb holders. My new tank has a single non vacuum petcock. Not sure if this would play into my issue or not, but I have been riding the bike since early fall this way.

Tonyc, it's OK to take the bike for a spin without the air filters? Assuming I can keep her running.
 
Chris I wasn't suggesting a rebuild. I assumed the bike was running and riding. Slowly you began to notice more decel popping and then alittle sluggishnish till it got past to the mid range then took off like old times but the popping is worse. Now it won't even make that. imo your pilot jet or maybe the circuit is clogged. Starving for gas, not getting too much air.
Are you fiddling with the choke to keep it running?
Carb work (on these) really is more time consuming than difficult a job.
 
weekendrider: Even mid range was a little off. Didn't play with choke to keep her running, just subtle control of the throttle seemed to help. Thanks for the clarification. I've had the bike for two years and never rebuilt the carbs, nor do I know if they have ever been rebuilt. So probably not a bad idea to pullem and cleanem.

Thanks Tonyc, will give this a try tomorrow.
 
The K&N pods that are the tapered ovals will give you an off idle flat spot. Most noticable at a steady cruise. The pleated element and the taper causes tubulance in the air flow. This causes a weak vacumm signal to the diaphram, and the slide won't lift like it should.
The longer straight K&N maybe ok, The Uni-Filter is a straight foam filter that doesn't disrupt the airflow in the carb and eliminates the flat spot. Cheaper than the K&N's, work better, a win win.
Leo
 
Hey DirtyErnie, To answer your question no. When I put on my new fuel tank I switched to a single high flow non vacuum Pingle petcock. Blocked the vacuum barbs on the manifolds as well.

Thanks DE
 
20 minutes seems like a long time to let the bike warm up, how lon do you leavve the choke on? First thing i wouldcheck would be the spark plugs, sounds like they are fouling
 
Tried to run the bike last night without the air boxes to see if they were the culprit behind my loss of power but ran into a new symptom. The bike would start fine but would die shortly after starting. I could play with the idol to keep it running but as soon as I gave it gas it would die. Is this another sign pointing to the carbs? Air boxes looked fine to me. I did clean the air boxes in kerosine last fall and lubricated them with a spray on lube. Don't think they are the issue though.
 

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