Starting problem - '87 430 auto

A month ago I decided to drag my bike out and check it over in anticipation of going for a ride. It had been sitting for about 2 1/2 years so it was about time. I pulled out the air filter and it crumbled in my fingers - very strange .
Anyway I put in a fresh batch of fuel at 33:1 ratio and tried to start it - no joy. Not even a cough. In went a brand new NGK B8ES - still nothing. A brand new Iridium plug - the same story. I eventually got it running when I used ether/engine start spray.

Last weekend I tried it again and it never ran at all !! All I managed to do was flood the cases with fuel - gunge was dripping out the exhaust manifold on to the exhaust and down on to the floor. I heaved it upside down and gunge dripped out the plug hole and sprayed out when I cranked it over. I left it sitting upright all last week with the plug out to let it evaporate and tried again today. NOTHING.

I think that 3 new plugs can't all be duds. The plugs are wet after a few minutes of kicking so I know that fuel is getting through but the bike just won't fire. I tried the ether spray again but no joy. I checked the ignition wires but nothing has changed from when it last ran. I am naturally left footed so I can get a really good swing on the kick-starter but it just won't talk.

I pulled the ignition cover off and checked the timing. It has an MZB ignition - the flywheel line and red dot (on the backing plate) line up at 2.3* BTDC. I can't find the original instructions for this system - is this correct? I reckon that, even if the timing has moved a little I should still get some sort of reaction.

Apart from an ignition problem I am stumped. Does anybody have any suggestions

I forgot to add that it does have spark at the plug. And I do get a tingle if I take out the plug, hold it in my hand against the head and kick hard. It doesn't kick me across the garage but I have never had this starting problem before - not like this.

Have you checked your earth/ grounds ? After 2 1/2 years of sitting there may be some corrosion preventing a good connection of them .

I would take carb off and clean and make sure needle and seat are sealing. you may be getting to much fuel in the base from bad needle and seat make sure petcock isn't leaking. Sounds like base is flooded.
Bill

I have just got home from work so I took out the spark plug, I used a long screwdriver to make sure that piston was at the bottom and turned it upside down. Straight away I had a pool of petrol on the floor as it ran out of the plug hole. I will let it sit upside down for an hour or so and then back upright again. Then I will strip the carby.

The tank petcock does not leak - I had it sitting on the floor all last week and no sign of any leakage.

Can you recommend any particular product for cleaning the carb or is it just a case of a good clean with degreaser (to remove all fuel and residue), thoroughly wash in clean water and then blow all galleries thoroughly with compressed air to finish the job. Removing the needle seat is a fiddly job - do they just need a good clean to remove dirt? Or it it worth just replacing the set with new?

My 88 250 used to do that all the time and so does my 87 430, sometimes after sitting just a few months. So I this and it hasn't happened since.



Takes forever to get all the gas out too. I roll it down a long hill then put it second with the spark plug out, seemed to work the best.

When you have the carb apart take out all the jets and then clean with Carb Cleaner, not degreaser. Soak the jets in cleaner, make sure you can see through them. Don't forget the little hole on the side of the needle jet. If I don't completely. disassemble the carb they never run right.

Rolling down a hill with plug out makes a mess on bottom of tank and frame if there's a lot of gas in cylinder and could start a fire if you don't have an ignition switch with an off position.

I take a Qtip and put in a drill with some rubbing compound on it and clean the seat with it. It polishes the seat nice and smooth.
Bill

can you actually bump start an auto???

No, Mine won't. I wasn't paying attention, didn't notice it was an Auto.

We I stripped the carby completely during the week and gave it all a good clean with carb cleaner. Back on the bike this morning and it fired up after a dozen or so kicks. it seemed to be running ok until I made the mistake of turning the choke off too early - it died and wouldn't restart no matter what I tried. Eventually I noticed the tell-tale drops of gunge on the concrete - the cases had flooded again. Upside down and another pool of petrol on the ground.
I removed the float needle and seat and gave them a good cleaning with cotton buds. I don't have any cutting compound so I used auto paint polish instead. Ok you can all criticize me for doing this.
I even rechecked the float level and it was 18mm. I have bumped it to 19mm and we will see what happens.

What I have now done is test if the needle seat really is leaking. I reinstalled the carb with a wad of paper tissues rammed into the throat on the engine side. The tank is on and the fuel tap is turned on. I will leave it for a few hours and see if the tissues are wet or dry. If they are dry then the needle seat is not the culprit.

Oooops I missed that it was an Auto...

Is the float moving up and down freely and not sticking if you tilt the carb back and forth. Try blowing into the fuel inlet and tilting carb to make sure the needle is sealing. does the float on your carb ride on pins in the bowl? Not sure if floats on that carb are solid or hollow if hollow check for hole in floats.
Bill

I have just taken the carb off and checked the wad of tissues that I stuffed into it yesterday afternoon. After sitting for 16 hours with the fuel turned on the tissues were bone dry. This tells me that there are no problems in the float bowl with the needle and seat or the floats.

The only thing that I can think of is that I have stuffed up an adjustment during my attempts to get it going. Yesterday I did find that I had not screwed the idle speed in far enough - it seems that the tip pushes against the slide and causes it to rise up. If the slide was all the way down could this cause the choke circuit to be working extra hard and sucking too much fuel into the engine.

I have the air screw 1 turn out from bottom - as per the manual. Can anybody suggest a setting for the idle speed knob on the left hand side? At least a starting point as I can't find anything my owners manual?

In the meantime I am going to check over all the electrics yet again.

I checked all ground points and all connections - all good. I then tried to start it again and after about 10 minutes I had to turn it upside down again and drain the cases. Only a small amount came out this time.

I decided to check the spark. With the plug out and holding it in my hand against the head (unpainted part) I could only get a tingle - even giving it biggest kicks possible. I always start it sitting on the bike so I know how to really swing on the kickstarter. I decided that I might have stator/rotor problems so I pulled the rotor and found what appear to be scrap marks on the inside. See the photos.

Yes the rotor has scoring marks on 2 opposite sides. I included a photo of a good part - and stuffed up the loading of them - sorry.
I suspect that my rotor might be out-of-round because the scrap marks and grooving are opposite. Would this be a possible cause of poor spark performance?

Looks like the flywheel or the stator came loose at one point and where rubbing. Usually that causes the stator to over heat and burn up one or all of the coils. Happened to me on my motoplat, now I run the Vape ignitions too. Here's the instructions but they don't say what the ohm values should be for testing.

Here are a couple of photos of the stator. As you can see all the coils have rusty ends except the 2 small black coils. They are nice and shiny on the ends indicating that they have been rubbing on the rotor. Are these 2 black coils related to the ignition function of the stator?

If so then do you reckon that this is my problem with a weak spark?

Looking at the second picture, the far right coil appears to bent? Inspect the inside the flywheel for missing or damaged magnets.

The magnets are all there. The rotor does have rubbing and some deep scratches (grooves) on the inside. It was on tight and the nut was done up tightly so I don't think that it had moved on the shaft.

This strange looking coil is as I got it when it was new and it previously ran ok like this.. When I was cleaning out the cases to ensure a good tight fit of the backing plate I did find what appeared to be a plastic powder - this fits with the scrape marks on the inside of the rotor. It would seem that some plastic coating has been scraped off the rotor magnets. You can see it on either side of the of the silver metal ends. This also fits with the 3 black coils in the second photo being bright while the others are brown and oxidized.

I had a thought while I was sleeping - Will the octane rating of the petrol make much difference? The manual states 95 or higher. I previously used 98 grade but this time I am using 91 - what I had available at the time. Would this really make so much difference that it won't even start?

Octane wouldn't make that much of a difference. You should have felt a really good jolt when checking for spark.

I still think its a Spark problem. Will it run on starting fluid? If not it's a spark issue. Check all your connections and grounds. Make sure the ignition coil has a good ground where it bolts to the frame under the tank. Disconect the kill switch wire at the coil.