Stator and r/r question

[posplayr]

Apparently, some folks are still using original 30 year old stators and r/r's - I just replaced my 81 stator ,but left the original r/r on, since it was working well. The stators are subject to alot of heat and heat gets worst as rpms go up- basically the ac frequency increases and adds to heat build up. No need to get discouraged- you just need to check output once in a while to ensure the charging system is working correctly. I'm skeptical of some of the aftermarket r/r's I've seen- the heat sinks seem too small. A member on here sells used honda r/r's ( actually Shindengen brand ) which have a robust heat sink and tend to be reliable- plus they have a sense wire to better monitor voltage output. These units are used on millions of bikes, atvs, snowmobiles. outboards, etc. Hey, all things wear out!

The primary determinant in whether your stator R/R lasts for 50,000 miles is if you put put around or drive it hard for extended periods.

Nearly all motorcycle changing systems with SHUNT R/Rs' are marginal at best and when pushed will result in a burnt stator. Some are better than others if they are able to disappate the heat in the stator which is a function of:

• rotor magnatisim
• heat conduction path efficency
• cooling oil flow to the stator (so keep oil level topped up).
• weak function of stator windings

That is on a good day with good connections. It goes down hill from there.

[tom203]

The primary determinant in whether your stator R/R lasts for 50,000 miles is if you put put around or drive it hard for extended periods.

Nearly all motorcycle changing systems with SHUNT R/Rs' are marginal at best

Well, sure, as I put put around at 2500 rpm I like/need a decent charging output; meanwhile you're at 7500 rpm , resulting in an ac frequency increase of three times. Fortunately your stator core is saturated- at some point counter emf fights back, but heat build up is fierce. Using the series r/r certainly makes sense- no argument there- but the shunt systems worked. The problem wasn't unknown to the engineers- yamaha and others used revolving field alternators to limit stator output just like our cars. They had their own set of issues; let's face it - we're dealing with a large rpm range here.

[bwringer]

Looks like JP Cycles stocks the Cycle Electric unit:

http://www.jpcycles.com/product/382-744

And Dennis Kirk:

http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=&store=&catId=&productId=201017&leafCatId=&mmyId=

I mention these two specifically because they appear to show stock levels; many online stores leave you guessing as to when they might ship your part.


Also, FWIW, my GS850's stock stator lasted 102,000 miles. (Even when I rebuilt and installed a different engine, I re-used my original stator.) The stock R/R was working fine when I replaced it with a Honda R/R at about 45,000 miles, and I likewise cleaned all the connections on the bike pretty early on. In other words, the stator never experienced the strain that many do of coping with bad connections and other failures. More than 100,000 miles may be some sort of record...

[posplayr]

Looks like JP Cycles stocks the Cycle Electric unit:

http://www.jpcycles.com/product/382-744

And Dennis Kirk:

http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=&store=&catId=&productId=201017&leafCatId=&mmyId=

I mention these two specifically because they appear to show stock levels; many online stores leave you guessing as to when they might ship your part.


Also, FWIW, my GS850's stock stator lasted 102,000 miles. (Even when I rebuilt and installed a different engine, I re-used my original stator.) The stock R/R was working fine when I replaced it with a Honda R/R at about 45,000 miles, and I likewise cleaned all the connections on the bike pretty early on. In other words, the stator never experienced the strain that many do of coping with bad connections and other failures. More than 100,000 miles may be some sort of record...

Did your stator show any evidence of excessive heating?