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**dasuchbe** · 08-09-2002, 05:33 PM

Update

After putting it back together I rode it up the street and back. Half way down it began somking and is now backfiring loudly out the exhaust. The smoke is blueish white.

On the plus side it seemed to have a lot better response on the throttle.

Is this something that I should get a professional opinion on? Or, since it is still running is this POSSIBLY something a newbie like me can fix?

**Mike Hart** · 08-09-2002, 05:47 PM

David, I'm guessing you have gas in the crankcase and fouled plugs. Check your oil, if level is high, or you smell gas in it, change the oil and filter, pull the plugs and clean them (if you can, you might need to burn off crud with a propane torch or such) and see what happens.

If you're fairly mechanically inclined, you'll be able to do everything (almost everything?) that your bike will ever need.

Browse the tech tip forums, there is a wealth of information.

How did gas get in the crankcase? Sticky carb float or needle valve, leaky petcock, can cause that. Before you change your oil, you might make sure your 'off' position is working right on your petcocks (remove the fuel hose from the forward tap w/ engine off and petcock to off, it should drip not at all or very little.

**TopCatGr58** · 08-09-2002, 08:57 PM

Rough 81SH

Hey there Dave,
Yes, you may rise!!!

I have the same bike. You didn't tell us how you got the bike or how long you've had it!! Had it been sitting a good while before you got it? Well, like Mike Hart said, the fuel system on these things can be real buggy, and you need to make sure that there isn't any fuel in the oil first, otherwise the engine can be damaged very quickly if you keep riding it that way. Take the oil filler cap off and take a whiff, if you smell gas and not just oil, then there is a good chance it got past your carbs float needle valves, and trickled thru the carb throat, past an open engine valve, around the rings and down into the engine.

This bike has the "Octopus", a mess of hoses running from the petcocks, to a vacuum controlled valve, then to the carbs. You mentioned that it idled roughly but if you put it on prime it smoothed out, that sounds like it's NOT getting enough fuel.
The "HOT" side may actually be the normal or good side, where it's getting enough fuel to actually burn and run, where as the cooler side may not be getting enough fuel, and not being able to crack the throttle shortly after starting it, even with the choke still engaged, also sounds like lack of fuel, and only after it has run a while, warmed up, shook the carbs with the engine vibration enough to perhaps loosen the floats and needle valves to drop and allow more fuel to fill the carb bowls, will it then let you give it some throttle!?!?!

When on prime, it bypasses the Octopus's valve, and goes straight to the carbs. You'll need to do some good diagnostics on your fuel delivery system(the tubes). Pull the tank and octopus and hoses, then turn the petcocks to on, have a vacuum hose attached to the octopus valve, then apply a vacuum to that valve, and see if fuel flows from the hoses where they would attach to the carbs. If not, then your octopus is bad. BUT, also take the hoses off the petcocks, and see if it flows in off, on, Prime and reserve. Fuel will come out of either petcock outlet depending on which setting you have it, except for OFF. If it doesn't flow very well, then you could have clogged strainers, petcocks which might require a rebuild.

The main purpose for the Octy is to control the fuel and not let if flow unless the engine is running, so you don't have to remember to turn OFF the petcocks, several of us have just ripped out the Octy, and rigged the lines from the petcocks into a "Y or T" fitting,(there are some with the Octy tubing you can use) and then to the carbs, with or without inline filters, just have to remember to turn off the petcocks when turned the bike off to keep from overflowing your carbs....especially if their floats and needle valves aren't working perfectly, or you'll possibly end up with gas in the oil again.

You'll probably want to tear down the carbs and give them a bit of a cleaning, you can do this without separating them from the rack or each other, so you can maintain some semblence of synch when you put them back on. If you can't get them cleaned soon, you may want to run a 1/2 can or less(see directions on bottle) of SeaFoam or Techroline in a fresh tank of fuel, might help to clear the idle circuit a bit.

Other folks have posted that backfires can also be due to inadequate vacuum where the carbs mount to the engine, a leak in the intake boots, that could also contribute to less vacuum to the Octy valve, again restricting fuel flow to the carbs.
Good luck, keep us posted.

**dasuchbe** · 08-09-2002, 09:46 PM

Thanks

Thanks for the info, I am going to change the plugs and oil tomorrow.

As to the carbs, if I leave the petcocks on, it leaves a rather large spot under the bike.

Also, the bike WILL NOT start with the choke on, in fact it will kill it if I set it to half while ideling. But if I give it gas, up to about 3000 or above, I can choke it and it seems to be smoother. but dies as soon as I idle it.

I have also noticed kinked lines on the side that runs hot, so I am going to replace them all. I had the tank off today and the petcocks did not seem to leak while it was off.

As to how I got the bike, it was from a family member. I traded it for an air conditioner. Someone rode it quite a bit last year but it sat most of the winter. About a month before I got it they supposedly cleaned the carbs.

So if I am careful, it is possible to work on the carbs without messing the sync of them??

Also, I have not checked yet, but can you get oil filters from an autoparts store or dealer only??

also, what is this:
1/2 can or less(see directions on bottle) of SeaFoam or Techroline in a fresh tank of fuel

I thank you guys for all the help so far. I am getting discouraged about it, I hope I have not been taken on this bike.

**Mike Hart** · 08-09-2002, 09:56 PM

Taken? for an air conditioner? No way!!!!

Techroline is available almost everywhere (carb/injector cleaner), Seafoam is better, harder to find, try a marine shop. No, not Semper Fi, a boat shop

Synch is no big deal. See tech tips for
pre-synchronizing carbs

OEM oil filters are available, but Fram CH6002 is fine, can get at any auto parts store, tho they may not have it in stock, order a few.

Relax, cruise the tech tips, it'll all happen good for you, a little patience and you will be amazed.

**crunchbird** · 08-09-2002, 11:58 PM

Part of the problem could be Bad Gas. If you are running gas that has been in the bike since last winter it will confound your analysis. You have some other little things to correct, but decent gas is basic.

I have had a good bike go bad seemingly overnight, very mysterious and frustrating, no adjustment was working, and a friend clued me in that I got a tank of el cheapo. Added good gas and end of problem.

Your air conditioner is more fun than his, no question.

**TopCatGr58** · 08-11-2002, 09:58 PM

Traded for an Air Conditioner!!!

Well, there's an idea for your bike's name:

Cool Breeze, or Hot Wind, something like that!?!?

Keep us posted on your progress!

**Jdwags** · 08-11-2002, 10:13 PM

sea foam is also at most NAPA stores...

Got a great deal there.. shucks.. i'd trade my ac for another bike.... especially an xs

**maxim4rob** · 08-28-2002, 03:36 PM

Just read about your problem. I have an '82 1100 Maxim and can't really help you out but just to say you're not alone. I have the same problem with #3&4 cylinders running hot while #1&2 run cold until I start driving the bike. After awhile all 4 heat up and run reletively well. However, I also have some backfiring. I have tried the techroline trick and it seems to help so I think the problem is in the fuel delivery system. The bike sat for 2 years before I bought it so the carbs need to be removed and cleaned. I think we're both on the right track. Good luck.

**cabinover** · 08-29-2002, 05:58 AM

Maxim4Rob, while your problem is usually a dirty carb, (backfiring/lean condition), I would look at fuel flow from the petcocks. If your Maxim has 2 petcocks, one feeds #1&2, one feeds#3&4. Is this idleing on the centerstand or the side stand? Shouldn't make a difference but low gas in the tank will fall to #1&2 petcock on side stand. Just a thought

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