Maxim revisted

[Angie]

Hey Ken!

Hi Ken, Not sure if you remember me or not, my special is listed in the photos, The black one with the checkers, I was on the list afew years back, man think it was longer LOL. The custom painter, anyways just wanted to say hi. Hi LOL

[Ken Talbot]

Yup, I thought the name and general location sounded familiar. If all else fails, you're going to have to toss your bike in the back of a truck, drag it up this way one weekend, and we'll get it sorted out. Yours wouldn't be the first to come in from along ways off.

This is the one, eh?


Any good suggestions about how to get a very subtle HOK ice white pearl flame just barely showing through or over ice violet pearl?

[randy]

Angie,

As Ken said, try the solder fix in the TCI box and clean all of your connections in the igntion circuits. that should rule out the TCI as the problem, Then go through the coils, ballast, plug caps. BTW, are the coils 81 or 81?

You can find the solder fix instructions here: Randy's XS Page

Also, with an 80 engine and a 4RO TCI, you'll have about 20 degrees TOO MUCH advance at 4000 + RPM. Pull the pickup mechanism and wire tie the advance weights so they don't move. If you don't, the resulting detonation wil eventually bang holes in your pistons.

Another alternative is to get a rotor from an 81. Basically, the rotor and the coils need to match the TCI box.

80 = 2H7 TCI, Mech advance, 1.5 ohm coils, ballast resistor

81 = 4RO TCI, no advance, 3 ohm coils, no ballast resistor

Keep us posted on your findings

[Angie]

Maxim revisted

Ok here's the scoop my the Maxim, I tested the coils which test fine. Also decided to test the thing a ma jing that shuts down the engine if the bike goes down, also kick stand..... you know everthing. NOTHING, HELP any ideers?

[ratbyk]

?

Angie, more background is going to be needed to help you. I assume that your bike does not run? It takes 3 things to run;
1. A reasonable amount of compression. (have you done compression test?)
2. A reasonable fuel charge. Are you sure that you are getting fuel into the cylinders?
3. A good spark at the right time.
Make sure that these three factors are present and get back to us on what is missing. From there we may be able to help you.
Ken/Sooke

[Angie]

maxim

Hi Ken, Yes it is getting gas, there is spark but it seems weak. The coils test out good, pick up it fine as its the maxim system which is alot better imo. It seems to me to try and start and fire. Its acting like a Vulcan I borrowed once and the clutch safety thing a ma jig thought the clutch wasn't pulled in, the bike would burp and fart but wouldn't run, of course I checked these things out also, this is getting to be a big Mystery, that puppy might be going back in the back for summer LOL

[TopCatGr58]

Okay Angie and Ratbyk,

I merged her first thread with this one, and after reviewing what she had posted earlier, there are still some questions that need to be answered.

She says she swapped an XS engine into the XJ, but sounds like she didn't change the TCI, and Randy already posted that the Pickup Coils for the XS won't work with the XJ's ignition!

So....Angie, what engine series is in the Maxim, and what ignition system are you running, the XJ's 10M box, or did you also get the proper XS TCI, either 2H7 or 4RO to go with the engine??

You may be mixing apples and oranges here if you haven't swapped the pickup coils on the XS engine for the ones the XJ uses, and if it's a 78-80 XS, you're getting cent. advance kicking in as well, and the XJ's TCI incorporates both cent. advance and vacuum retard in it's electronics, again adding more timing problems using the XS's !? So....until we know what's in the frame, we really can't make truly educated suggestions!
T.C.

[Angie]

Hi TC, Its a XS motor I believe a 80, and the pickup coils are from the Maxim, which is a 82. Hope that helps, this is getting alittle frustrating considering the bike was running in October and now its time to ride and it won't run

[ratbyk]

Used to run?

Whoa, back the truck up. If this bike was running OK in it's present configuration last Oct. then all this talk of missmatched black boxes, pick up coils etc will not apply.
Go back to the basics. Pull the plugs and do a compression test. Clean the sooty plugs or put a fresh set in. Drain out the old gas and put fresh fuel in it. Recheck that you have a decent spark at each plug. Start the bike making sure that the kill switch is not in the off position.
If still no fire try some ether starting fluid. Be carefull the stuff is dangerous (explosive and will make you drowsy in closed garage.
If it has compression,spark and fuel it will run.
Ken/Sooke

[Angie]

Hey Ken, Tried absolutely everything this is why looking into something electrical, maybe moisture? The bike is in a barn all winter with a cement floor but not heated. I don't have a book on a Maxim just the XS , I know they are pretty much the same other then in the electrical department. Well guess I'll have to keep trying, not much longer though LOL.

[Jerry]

Just to recheck....

The side stand switch is often a culprit. Put the bike on the center stand, then wiggle the side stand near its down position. If the place is quiet you will hear a click as the relaty cuts in and out. When you hear the click the bike will start. It will probably happen just before the stand is in the full down position.

Next is a clutch switch built into the left handlebar. This switch is to keep you from starting the bike while in gear with the sidestand up. It is a simple plunger device activated by the clutch lever and 2 wires that go into the headlight shell. Mine broke soon after I got the bike (since replaced) and all I did was jump the 2 wires together. This makes the safety circuit think the clutch lever is always pulled in. Caution: with this mod you will be able to crank the bike while it is in gear and clutch engaged!

3rd interlock is a gear position switch...the one that shows the green Neutral light when you are in Neutral. Does not often go bad, and if your light comes on normally I would suspect one of the other interlock switches. However, if it is bad it will act as an interlock (with the clutch switch) to keep the bike from firing if it thinks the bike is in gear with the clutch out and sidestand down.

The side stand switch can be eliminated by following the wires up to a connector just behind the fuel tank. Unplug the wires, then jump all 3 bike-side connectors together. I made up a 3-way jumper with 1/4 in female spade terminals and a small bit of speaker wire. Again, caution is in order, as bypassing the switch will let you fire up the bike with the stand in the down position.

The side stand switch is no longer available from Yamaham BTW.

If these switches look OK and the mods don't help, the last is a strange situation where the battery has enough power to crank the bike but not fire the TCI box. New battery is the only solution for this scenario. Good Luck!

[randy]

Angie,

You say you've tried "everything", but have you tried to re-solder the connectors inside the TCI? This is a universal problem with any year XS or XJ and will cause weak spark. Take a look at my website for instructions:

randy's Xs page

[ratbyk]

Miss Match Ignition

With a mixture of XS/XJ ignition parts another possibility may be:
Is there ballast resistor on this bike? It sits under the left front corner of the fuel tank. Bolts up to the frame rail just behind the horn location. It is about 2 1/2" long, silver in colour. Flat on one side, oval on the other. Held in place with one bolt that a 10mm wrench would fit. It has 2 red wires with push on bullet type connectors. You can by pass by simply disconnecting the two push on connectors from the resister and connecting them back up. This will eliminate the resistor from the circuit and allow full battery voltage to flow through the pickup coils and onto the coils. If all else fails it is another step in the elimination of possible problems.
Ken/Sooke

[ratbyk]

Ballast Resistor

Further, you can by pass the resistor without removing the tank. There is enough handroom up there to do it. Awckward but doable.
Ken/Sooke

[TopCatGr58]

Hey Ken/Ratbyk,

She's using the XJ's ignition system, no ballast resistor used on that model.

Angie, on the engine, you're using the XJ's pickup coils, does the engine still have the vacuum module on the timing plate? IF you're using ALL XJ ignition parts, then the XJ uses a Vacuum sensor box under the tank, it sends signals to the XJ's TCI about vacuum load and changes the advance curve accordingly, BUT IF YOU STILL HAVE A VACUUM HOSE connected to the vacuum module on the timing plate, AND also to the little black box under the tank, then you need to UNPLUG it from the timing plate unit, just plug it off, otherwise you're getting double ignition retarding effect with both the vacuum box and the timing plate module connected!!!

I hope this is it, i know how frustrating it is to have an engine that just won't start!! T.C.