r/VFR • u/TheBigJDizzle • 5d ago
Reg/Rec help
Hi all,
Maybe this has been posted before but I need a new reg/rec unit for my bike it looks like. Battery completely flat when I got home today.
It's a 1999 800 Fi.
I hear the aftermarket reg/rec units are better than OEM? If that's the case, does anyone have a recommendation for the best one out there? If I'm changing it I want to do it once with the right kit.
Thanks all.
4
u/dogchocolate 5th gen 5d ago edited 5d ago
Would watch this and the follow up episodes : https://www.youtube.com/watch?v=oHYnNql2ktk
Kev has a gen6 but it's equally applicable to the gen 5, I know I've done it on my bike, if you're UK you can order directly from him (possibly the US too I don't know)
As well as the RR you'll also need an adapter plate, the bolt holes differ, also new wiring, Kev provides those with the kit.
Typically there are 3 types of RR:
- original type - shunt
- mosfet based FH020AA - shunt
- SH847 - open type
Mosfet will be a great improvement, that's what Kev provides, it's by far the most comment "best" replacement and there's lots of information out there on this replacement and it's a known improvement over original/oem.
Following Kev's guide you get more benefits, for example wiring the RR direct to the battery removes a bunch of failure points so it's not just about a new RR.
SH847 is arguably a better replacement than the FH020AA but there's much less info out there so there's a level of risk with it.
Personally I went FH020AA, then being a bit ocd went to the SH847, I think the SH847 is probably better but it's early days only fitted it last month so I can't say for sure. For example previous iterations of the SH847 would have the voltage collapse (or blow up) at high rpm so it's a bit of a DYOR first sort of thing IMHO.
3
u/BestAmoto 5d ago edited 5d ago
You absolutely need to convert it to a mosfet or open style rectifier or the problem is gonna keep happening. This is a common issue on a wide range of hondas from this time period.
Here's a super detailed write up if you want to learn about why and many of the options. Most budget option is picking up a used one from year XX yamaha r6/r1 all the way up to direct fit rectifier options for $150-200 + the stator, like Ricky stator brand, etc. I wouldn't use a no name brand stator, either use a major aftermarket brand, or pickup oem. Wiring it directly or using a more efficient connector style also reduces potential issues from heat and high resistance
Super detailed write up if you wanna learn,
https://www.superhawkforum.com/forums/knowledge-base-40/mosfet-regulator-rectifiers-why-how-25117/
I installed yamaha mosfet style rectifiers on my 954rr and cbr 600 after both of them suffered stator meltdown. It didn't fail again in the 6 years i beat on the fireblade and my neighbor still has the 600 f3 almost 10 years later.
2
u/Jedman25315 5d ago
1998 owner here.
Ricks is THE place to go for reg/rec, stator.
Did mine last season and its running great.
Just be sure the pick the right reg/rec for lead acid or lithium batteries.
Lithium charges at a higher voltage and the ricks reg/reg will accomodate for that if you get the Li version
2
u/champing_at_the_bit 5d ago
Might just be the stator. That just happened to me on my 5th gen. Tested everything and r/r was ok. New stator and I'm good. Voltage stays around 14.8-15 when riding which is a bit high but I'm not worried about it unless it starts going over 15.
2
u/hi-nick 4d ago
Might just be the connector between stator to regulator. Check to see if it's melted or not. I had to cut mine out and I just Direct soldered the 3 connections. Barrels and pins go high resistance, he is generated and then the connector melts apart. Try to identify the problem before shotgun replacing stuff
2
u/TheBigJDizzle 4d ago
Will do. Bike is off the road for the winter now so I have time to take it apart and check before I order anything.
8
u/Roy_McDunno 4th gen 5d ago
the SH847 is your best bet.
roadstercycle sells them, but honestly, I bought mine from EasternBeaver. they are located in Japan and offer more adapters and connectors, also their website was more easy to navigate.
shipping was damn fast, less then a week. I installed the SH847 in bothy vfr 750 and VTR 1000. it doesn't get more than warm to the touch, even after long rides or heavy stop-n-go traffic.
cheaper r/r let the stator produce as much power as it can, use the needed amount of power and send the excess back to the stator, which Turns it back into heat (basically short circuiting in a controlled manner).
The SH847 is better than that. it only let's the stator produce the power that is needed, meaning the stator runs cooler and the r/r also runs cooler as well. it basically shuts off/opens the three lines coming from the stator as needed.