Bogging down problem

[Steve Minor]

OK........here's the situation and what I think might be the problem.

My 77 400 GS6 is bogging down in 3rd thru 6th gear something terrible and I believe it's a "gummed" up float or jets. Yesterday it did it and the carb really loaded up badly. I shut the petcocks and held the throttle wide open until it finally cleaned out. I'm afraid I might have been rushed last time I rode and left some premix in the float bowl. That was 2 months ago.....anyone care to guess? Or, could it be a weak ignition problem? Or a combination?

[firstturn]

Steve,
  I think your analysis may be correct.  But I don't know if the tank was properly cleaned when or ever? Also you might let us know about how many hours you have on the top end and also the condition and care given to the aircleaner.  Not saying you, but I have had oil actually coming from the aircleaner guming up the carburetor.  Just throw us more info and we will try and help you.
  Your a sharp person and should put this one behind you quick.

Ron Carbaugh

[Steve Minor]

Ron.....the motor is a fresh Lucas rebuild. Bobby did it for me last year, just before the 2003 RR. I just barely had time to break it in before going to Dalton. It performed flawlessly...(better that I performed I might add). Since then I haven't ridden nearly as much as I wanted.... maybe an additional 12 hours. The air cleaner is always serviced after riding. The tank seems clean(famous last words). I think it's a simple fuel problem, but I wanted a second opinion....I'll tear into the carb this weekend.

Thanks Ron
Steve

[firstturn]

Steve,
  I don't want any input to start this gas message board again, but because the oil companies are being required to; quote "climatize and regionalize" and what other words the D.C. representation wants to think up.  The gas we buy have additives that can do funny things when oil is introduced.  To a tank full of gas & oil mix that is left(in my opinion) for over 30 days you are leaving yourself at risk for build op of left over chemicals.  And remember that this changes from region to region, soooo if I give you a recomemdation on whay I see in Texas itmay change everthing to someone in the Carolinas.

************I am not a chemical engineer, but I do know plenty since I worked for several years for Mobil Oil.  And just like Racers they don't all agree on the above comment.*******************************

Stay in touch Steve and as always email me directly if I can help.
[email protected]


Ron Carbaugh

[Steve Minor]

I'm usually good about draining left over gas into a special can...it's later used in the lawn mower. The Maxima Castor 927 Oil I use gives me the sweetest smelling mower in the neighbothood!

I'm sure I just forgot to drain the float and tank before storing the bike last time.....I'll give them both a good cleaning this weekend.

Got to get ready for Tulsa!

[wildman]

I have seen the early Bing white float assy. get saturated and heavy. The later black floats are much better and interchange with the white unit. Also check the float needle for wear and grooving at the tip. There is a late model float needle also. Good luck. Dan Pagel

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125

[hrbay]

Do the petcock strainers. Good idea to drain every time, unless able to ride every day. Old gas, gas cap too tight or not venting, dragging brake, look at everything while it's on the stand.

GC

[Steve Minor]

OK Guys.......help me out here on my 77 400 GS6. I tore into the carb. No trash or oil residue but I and cleaned it anyway...reset the float...blew out the jets....etc. I drained the tank and gas lines. Mixed a fresh batch of gas...Fresh NGK B8HS (old one was brown and wet)....Two kick start...I'm stoked! Take it to a trail close by... Same thing happened.....loads up something awful in 3rd thru 6th. Top speed in 3rd is about 20 MPH and it bogs. Tell me if I'm wrong, but I believe you need 3 basics to run...(1) compression (2) fuel and (3) ignition. The compression is great and now the fuel delivery system has been checked out. That leaves ignition. Could I have a poor ground or weak coil? Or poor coil ground?

I'm sure some POG "brother" has the answer for me.

Thanks
Steve

[Rain Man]

turn all the lights out, put a new plug in there and see what color you spark is.  How old is your "motosplat" [?] I have a 77 Gs 400 and its running a tad lean, but on the lower RPM range its fine. It can be boggy if you don't roll the throttle on.

Raymond
Limington Me.

[wildman]

Mouse nest in the airbox or frame? Lighting coil wire hooked to ignition coil? Non-venting gas cap? Spark arrestor plugged up? Bad ground on coil or stator? Choke slide hanging down? Coil wire arcing to ground? Take float bowl off and turn on gas and make sure it pours out. Put a timing light on it and see if timing jumps all over. Check little screws that hold motoplat to stator adapter and to engine. Does it wind out in 1st and 2nd? Find the pepper in the salt.
Dan Pagel

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125

[hrbay]

Steve, you may have already found the problem, but if not, I would suspect the electrics... trying to check grounds is a little tedious, but I would try running another ground lead from the coil to a known, scraped, and clean point on the frame to see if you see a difference. Also, if your bike frame has been repainted you may have a weak ground from motor to chassis ( paint on frame motor mount lugs) which the magneto needs. Good hunting.

GC

[Steve Minor]

GC...I'm going to to just that this weekend. I have a spare coil too if I need to swap it out. I'm open to ANY suggestions!

This is an posting from 8/29 for reference.

OK Guys.......help me out here on my 77 400 GS6. I tore into the carb. No trash or oil residue but I and cleaned it anyway...reset the float...blew out the jets....etc. I drained the tank and gas lines. Mixed a fresh batch of gas...Fresh NGK B8HS (old one was brown and wet)....Two kick start...I'm stoked! Take it to a trail close by... Same thing happened.....loads up something awful in 3rd thru 6th. Top speed in 3rd is about 20 MPH and it bogs. Tell me if I'm wrong, but I believe you need 3 basics to run...(1) compression (2) fuel and (3) ignition. The compression is great and now the fuel delivery system has been checked out. That leaves ignition. Could I have a poor ground or weak coil? Or poor coil ground?

[Big Mac]

Steve, If you rule out electrical, then it must be fuel delivery of some sort. I'm guessing you already backtracked to any recent changes you may have made prior to the problem? I recently serviced my son's ATV, cleaned the air filter and while I was down there, decided to pull the restrictive snorkel out of the air box and drill a couple of breather holes while I was at it. It ran fine for a short time, then bogged and wanted to die at anything above half throttle, although it started OK and idled fine.

Finally figured out that the extra air was making it run too lean, and only the fresh-oiled filter restricted air enough to put it in range of clean running. Check anything that might affect excess air flow as well as restricted fuel at higher flow.

[Rain Man]

Hi Steve, did you ever get your bogging problem straightened out??
 I ordered a couple of main jets for mine and went to a 182 main, and now the bike is picking up the revs instantly. IT felt like it was bogging down, but in actuality it was running out of fuel!! (white plug). I'm still curious if and what the problem was with yours, just for future reference
Dunkashain

Raymond
Limington Me.

[maicobuddy]

Steve,
I don't believe you have a fuel problem..but I could be wrong it wouldn't be the first time..it sounds to me like the baffle may be stopped up..have you pulled the baffle out of the exhaust pipe and tried it..it's a easy check 2 or 3 minutes..I had the same problem with my '80 Husky 390WR it ilded & ran good down low ,but as soon as I rolled the throttle open it started bogging down if I held it open it would bog it completely down when I checked the plug it was soaking wet & black..I checked everything else first and just happen to try the baffle..man it ran like a new bike with it out..Good Luck..maicobuddy:)