Early H1 Stator Rewind - Alpha Test - COMPLETED!!

[triplepoweredgpz]

Bump, I know he's got his hands full walms...but can't you get someone to do this? We got a place in Hamilton called black brothers that does stuff like this

[Walms]

Apparently Jim Hobbs will make coils as well... Since mine checks out resistance wise, I'm guessing it's a weak pickup. It would be nice to have a test that could be performed tho... Maybe there is?

[Jim]

I can supply the low speed magneto coil for an H2 or H1D stator, and for the KH400, Andrew. I don't have any of the others because they fail so rarely. I occasionally hear about someone getting the whole stator rebuilt by a motor rewinding company, but I don't have any specifics. If I needed to get one done, I'd call around, and maybe send photos to some of those companies and see if any would do the job reasonably.

A coil can measure OK with an ohm meter, but fail in use when it gets hot, or just when the voltage gets high and faulty insulation allows an arc. You might try putting a meter on your LS coil, and poke it in a few places, seeing if the resistance changes. I had a failed one that you could do that to, and the resistance would go all over the place.

[Walms]

Actually, we deal with a motor company that reconditions the old DC spindle motors when the customer is frugal, maybe I'll bend their ear the next time they are in.
In speaking with John, he was telling me that 4 of the coils are for charging and there is only 1 high speed coil and 1 low speed coil... If that's the case, most likely a pickup is the culprit, but at this point not even so sure it's just 1 cylinder.

[Jim]

A pickup could be the problem, but that's not what I'd suspect first. Don't you have EGT gauges? If it's only one cylinder misfiring at high speed, I'd think that would show up as lower EGT on just that cylinder. Then you could swap pickups and see if the problem moves.

The pickups operate at low voltages, so they're not particularly susceptible to insulation problems, and they put out more signal as the engine speeds up, so I'd think a pickup problem would be worst at idle. I'm just speculating.

Of course you could put your pickups on the borrowed stator and know if the problem is with pickups or stator coils. I realize that's not a 2 minute swap, however.

Something to keep in mind: The low speed coil is still putting out power to the CDI units at high speed. There is lots of overlap between the LS and HS coils. It's not impossible that a bad LS coil could be involved in your problem, especially if it has a bad spot in its insulation and arcs internally at high speed, but works fine at low speed. I'm not suggesting that it's the most likely culprit, but I wouldn't rule it out completely.

[Walms]

Yes, the temp sensors are a good tool and I need to get busy swapping parts out again now that jetting is confirmed.
The cold cylinder could very well have been jetting related.
I guess time to bust out the wrenches instead of procrastinating! Lol

[North]

Jun 28, 2016 5:58:26 GMT -5 Walms said:

Apparently Jim Hobbs will make coils as well... Since mine checks out resistance wise, I'm guessing it's a weak pickup. It would be nice to have a test that could be performed tho... Maybe there is?

I would drop test the coils (apply 100 volts DC and measure the voltage at each coil) and all coils should have close to identical voltage readings, bad ones are obvious. Other than that I would megger the coil(s) to ground as I would suspect insulation breakdown over time having these short to ground or turn to turn. If both of these tests (and resistance readings are ok) then your problem is elsewhere.

Thinking once I get settled in with my tools out of storage and what not I may set up a workbench to fine tune the rewinds into something really nice (and relatively cheap).

Daffey, wish I would have got your stator out but it met the same fate as the rest of my stuff in the trailer


P.S.

For the DC drop test it would require opening the connection and temporarily connecting all the coils in series with only 2 leads out... I know, I know. Not exactly what everyone would be bothered to do

[starsky]

How did you remove the stator windings from the housing? There are four machine screws to be removed, but the stator is still solid. Please help if you can as I am stuck.

[zambia]

As I recall, there are no more screws holding it - you probably need to heat with a heat gun and tap it with a rubber mallet.

[starsky]

Hi Zambia, thanks for the reply. I followed your advice and with gentle use of a drift, the stator came out fairly easily. So, big thanks!