new commando teething woes

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I hate buying new bikes and then try to set them up for my taste, but here I am chin deep in another commando. I did a single carb manifold from MAP instead of RGM this time since I do not like a dual carb set up. I ran the bike last night for the first time. It start decent enough, not as good as my other commando, but starts, idles ok, shifts w/o drag anymore since the clutch rod seal was installed. so I start out down the road and the bike seems to run decent in first and then in second, but when I shifted into 3rd it started sputtering and missing. I was only going about 40-45mph, but this shouldn't be an issue. When I pulled over it died. Started right back up and ran in first and second, not well but in third it started fowling up again. For the brief amount of time I ran it , 1 mile, I still am not sure if it really ran good at all on my return trip since I was using the throttle on and off in nuetral to keep it moving or from dying and was concentrating on traffic and getting home. If there are any thoghts on this please yell out. I am at work all day and can't look at it until tonight, but am interested in thoughts of others. One thing I did notice at a glance is the MAP manifold makes the carb sit almost exactly horizontal and the stock or RGM manifolds make the carbs sit canted forward. The floats on my spare carbs are set at the prescribed .080. The carb on the new bike is identical to the one on the well sorted bike. sleeved carb, stock jets and needle height. Just looking for thoughts at this point, thanks. On a positive note I rode the other commando all day through the area state parks in the 90degree heat for 6 hours, slow to moderate speeds w/o a flaw in performance.

Tim
 

grandpaul

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Are you sure you didn't leave the choke (enricher) on? Sounds like that (stumbling over 30 MPH) when the slide is still down in the carb throat.
 
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No, choke lever/slides removed and hole blocked off, pilot circuit drilled out for cleaning access as well.
 
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I'd suspect something like taillight ground wire shorting out. hbot
 
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Symptoms should have been recognized, but I didn't quite remember them from years ago when I last had this issue. Easy as the main jet holder is coming loose causing the issue. Will blue loctite work in this environment?
 
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Sounds like fuel starvation to me. Check your tank breather. If it goes OK in first and second, then it will go OK in third and top if the carburation is fine. When it starts to die, open your fuel cap and see if it corrects itself.
 

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britbike220 said:
Symptoms should have been recognized, but I didn't quite remember them from years ago when I last had this issue. Easy as the main jet holder is coming loose causing the issue. Will blue loctite work in this environment?

A proper spanner will work in that environment!

In 30 years, 50+ Britbikes of my own and 20+ clinet's bikes, I've NEVER had that happen.
 
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Paul, I've had it happen twice, but this time appears to have maybe only contributed to the real problem. I tried running the bike again tonight and the same thing happened so I am at square one again. I only get about a half hour to an hour at a time to mess with this thing so figuring anything out is going to be difficult. The whole thing kind stinks.
 
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Four hours going through this thing and no norton joy. Ground good, carb the same as other sleeved carb on other 850, jetting everything identical. Boyer wires all appear to be in tact, but hard to tell if internally broken. What are the odds of a boyer being bad after 23 easy miles? Tank vent clear, valves perfect. I am going to try physically switching carbs from the other bike to see if there is some change and after that I could can the boyer for a new pazon I have, but that doesn't seem likely with everything being so new. I have to wait for the wife to get home to check timing and doubtful more will get done today with it raining. I am open to all other suggestions or help.
 
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How's the flow from the petcocks? I had some of those nasty tawainese ones with the rubber seal swell up on me. Just as you would try and gather any speed, it would start to sputter, about like you are describing. I popped open the cap, thinking the vent was blocked. That seemed to help, but in reality, I'd pull to the side of the road, pop open the cap, and the bowl would slowly fill. It would start and run fine, but just until I started to gather speed, and then the whole thing would start over again. Changed out the petcocks, and that's all it was. 'luck
 
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Where did you get them from?[/quote
]

I bought them from a well known seller on eBay, who I'd rather not name. Funny, because I had a set with the rubber seals for many years, and they lasted just fine. This "episode" was on my Interstate, and I replaced them with the Miles ones like they sell at British Bike connection. Larger alloy, with brass knobs. On bikes that the alloy ones would not look as good on, I've used the all brass taper type that I got from British Cycle Supply. They have not been perfect, had to disassemble and lap one, but it's been fine since them. Also have a set of BAPs on my Combat, and thery are OK as well. Just not that crazy about the looks of those, but they flow well and don't leak.
 
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The fuel flow is great, the taps appear to be pretty decent quality. I had a pair of poor quality on a trident a few years ago and it would lean out arounf 60MPH. Had a heck of a time with that issue. Dave I tested the boyer wires-black.white from the solder blob behind the plate to the first connection and there was 0 resistance wiggling the wires, same for the black yellow from same points. I also tested resistance in the longer wires separate that run up to the box, I pulled/wiggled them and again the black/white was 0 resistance and the black/ yellow is 0 as well.
 
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Is it a MkIII? If so, check the neutral light switch on the gearbox. Just a shot in the dark. You said it doesn't begin to miss until you shift into 3rd.
 
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Generally I like to see or have a happy ending to the threads I read, but this thread doesn't. As a last resort I took the RGM manifold and carb off of my other commando and put it on the new bike. I had like a dummy bought one from MAP which is garbage and apparently it does not work well or at least the one I got. I had joy for about 1.5 miles with the RGM and sorted carb and then things started to go bad. It started missing a bit intermittently nothing dicernable and I was trying to hear the little pop I could hear better over the wind noise and motor, but alas .5 miles later it started missing real bad and quit running. When I tried to start it again I heard a tink sound and now there is about a 1/4 inch of play in the left intake valve and the bike will not kick over. The saying If it weren't for bad luck I wouldn't have any comes to mind right now. I am at a loss, monetarily and mentally where to go from here. I'll have to think on whats next. I suppose I have to tear the top end down to even determine the damage.......................I can't figure out what happened. The valves were spot on there was no out of the ordinary noise, It just went bad quickly.
 
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I inspected closer today and found the left intake stuck open. I managed to get it un stuck, but now have minimal compression in the left cylinder, bend valve my guess. My question is when I take the head off to replace the valve can and assuming for peace of mind there is no other damage, can I just replace the bad valve and can the guide in the head be reused? I have not done valves before so advice is needed.

Thanks,

Tim
 
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Ugh, serves ya right for wrapping out a Norton so heartless : )
Could have been guide issues that trapped the valve, now its jarred marred too.
Must also think what valve bending impacted, piston, rod and fasteners to lifter faces and cam lobes to cam drive down to the oil pump snout.
Then again could just replace the valve and see what happens or not. That's got a longer tradition behind it than my depressing review. Its What I do if nothing else obvious as can always dig in latter if bigger stuff surfaces.
 
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hobot said:
Ugh, serves ya right for wrapping out a Norton so heartless : )
Could have been guide issues that trapped the valve, now its jarred marred too.
Must also think what valve bending impacted, piston, rod and fasteners to lifter faces and cam lobes to cam drive down to the oil pump snout.

:oops: rappin it out at a whoppin 55mph, maiden voyage so to speak, ending in disaster. Amazing how I went from simple carb/manifold issue to a top end tear down and at the least new intake valves in a very short expensive mile. Probably wouldn't be so bad if I had done this work before and was equiped for it. No one else in this area does this sort of work so I don't know where I'll go from this point. I am glad I have other bikes in the garage. Thanks for not making me too depressed. :lol:
 
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