Rectifiers

[Eikari]

Got a used stator from a 951 engine. Measured it and it´s around 0,7 ohm between wires. So the voltage is around 13,3 V at idle and increases as i rev it up. Should be ok for the next test ride.

 

[Sportster-2001-951C-Stock]

Excellent, sounds good. Was the original stator corroded? What max DC voltage did you measure, less than 15v? Was the 26v AC gone?

Nice project!

 

[Eikari]

Well, comparing them i noticed the original was very corroded on the inner diameter. So i think that was the problem. i only did DC measurement at idle since i didn´t put a hose on it. But when i cranked the engine, 12 volt low appeared. Is the mpem so sensitive for voltage below 12V that it displays a warning when the engine is starting up?

 

[Sportster-2001-951C-Stock]

Yes, those MPEM's are very sensitive. I'm confident they are even capable of determining rider gender somehow, they always seem to run a bit faster when the women are on them. ;i

 

[Eikari]

Went to a lake today and all went smooth. Engine pulling strong and no hesitation in acceleration. Almost finished with the first tank after rebuild. The only thing i can complain is the weather been not so good this summer..

 

[Mekanix]

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View attachment 20463

Went to a lake today and all went smooth. Engine pulling strong and no hesitation in acceleration. Almost finished with the first tank after rebuild. The only thing i can complain is the weather been not so good this summer..

So how long did it take you to go through that tank ?

 

[Eikari]

Well, when you have fuel delivery problems and also charging problems the ride is hampered by that. So the previous rides were just about 30 minutes. So finally, third test ride, it was a good 2 hours, i just called it a day by then. The weather was also not that good, rainy and windy.

 

[Eikari]

Few more pics. I installed a kill switch, no more need to unhook the battery after use. I painted the engine, exhaust system and carbs with Hammerite. And then plugs had a nice colour to them, so i think the carb tuning is at optimum.

 

[Sportster-2001-951C-Stock]

I feel plug color is somewhat dependent on fuel quality as well, seat of the pants feel is most important to me. No flat spots, a strong power band and yes, the plugs certainly should not be white! Carbon-free areas on the piston crown, especially 1/4~1/2 inch around the edges are the best indicator, a sign the piston isn't overheating from a mixture that's too lean

I never WOT ski's on the trailer but if I did, I'd want it to four-stroke.

Gordon Jennings' tuning handbook is here:

http://edj.net/2stroke/jennings/

Sounds like your ski is running well, very nice!

 

[Eikari]

I didn´t do a WOT on the trailer. I looked at the plugs after i had parked it in the workshop.

Interesting info from Gordon. Thanks for the link

 

[serkan80]

[MENTION=65504]Eikari[/MENTION], it's usually an issue with the rectifier, your battery is ok and so is the pressure. I hope changing the stator and rectifier would've killed your problem completely. Also, you might be measuring the current wrong since there should be current flowing through the wires. If the stator wasn't working at all you wouldn't be able to get these results, it wouldn't have even started, let alone the loose idling issue. Change the rectifier and buy one with at least twice the ratings that you actually require, just to be on the safe side so that it doesn't stop working anytime soon. Hope you get it solved soon.

 

[Eikari]

I actually bought a rectifier from SBT. But it wasn´t a a rectifier problem. The stator was shorted so i changed it. So the original rectifier is still working , always good to have a spare..