Spark Issue

[embrelleur]

Hi,

 

I just got this TY175 that was given to me. It sat for a couple of years and the last time the previous owner tried to start it, it wouldn't start. He told me there was no spark, and that when he opened the mag cover it was half fll of water. I started diagnosing with the knowledge I have and information found on the internet. First thing I found is that the ingnition coil is dead, open on the primary side, son I bought an aftermarket one. Installed it, cleanet points and set points gap and now I only have weak intermittent spark.

 

I will order new points and condenser, is there anything else I should check?

[embrelleur]

Is there a way to adjust the points gap tithout removing constantly the flywheel?

[shakennstirred]

Is there a way to adjust the points gap tithout removing constantly the flywheel?

only if there are slots in the flywheel ?

which are there on some bikes so you can adjust the points with the flywheel on

Edited June 2, 2016 by shakennstirred

[feetupfun]

while you are trying different points settings, set the clamping screw just tight enough to hold it in place. This makes it easier to make changes through the slot in the flywheel. When it is set right, you can then tighten the clamp screw fully

[feetupfun]

for weak spark after changing the stator coil and points, check that:

The coil laminations are not touching the magnets

The coil laminations are well earthed

The wire up to the HT coil has no broken or hard sections

The HT coil has a good earth

[embrelleur]

Tonight, I removed the stator plate, and cleaned it good, as well as the mating surface on the engins, so now I'm confident that my grounds are good. I ground down the paint on the HT coil mounting surface and replaced the wire between the condenser and HT coil.  Still weak intermitent spark. So now I have to source points and condenser I think, if I cannot get them locally I will order on the Internet, takes longer to get them though

[embrelleur]

I did change HT coil but not stator coil, as it looks good

[embrelleur]

I just ordered my ignition tune up from www.tytrials.com, should get within a couple of weeks, can't wait to see it running !!

[2stroke4stroke]

It is not uncommon for elderly TY 175 low tension coils to be kaput. I got mine rewound rather than go to what people have found to be an unreliable electronic system.

In its day the TY set up was regarded as very good so I saw no reason to abandon it. The modern rewind uses better materials than were available in the day.

[embrelleur]

is it expensive to rewind a source coil?

Edited June 3, 2016 by embrelleur

[feetupfun]

Last one I had done was about $AU100 (by a local auto electrician)

[feetupfun]

not sure of this applies to your source coil, but I have fixed a couple of TY175 source coils by unwinding the last few turns, to remove a corroded section of the winding. There are other ways for the coil to fail though apart from corrosion at the outer end. The winding might have a break/crack or have corrosion that can't be seen.

As for the electronic option, I have had a good run with ignitions from John Cane with TY175 and TY250 motors. Both ignitions are many years old now and had no issues. I do live in a dry climate though which might make a difference to reliability

[feetupfun]

another thought for your weak spark is to check the strength of the flywheel magnets

[johnjsy]

Very often engine to frame mountings become corroded,giving a poor earth return. Bypass this possibility with a heavy section of wire with a soldered on terminal each end, from an engine bolt then to the coil mounting bracket. Easy to do,but easy to overlook. Hope this helps,John.

[dadof2]

Very probably the low Tension / source coil is faulty. They are usually about £30 to £40. If you can't get them you can rewind them yourself.

 

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