2019 Beta 390 (350-430-500) RR-S - Engineering & Experiences

Discussion in 'Thumpers' started by motobene, Apr 8, 2019.

  1. motobene

    motobene Motoing for 51 years Supporter

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    After taking the MOSFET regulator-rectifier (R-R) unit to my shop in another state to modify it to fit the Beta and provide clearance to the fork tube owing to more steering degrees:
    Modified MOSFET SF-021-006035.JPG

    ...I was able to test stock and new R-R on the 2019 Beta 390 RR-S in The Land of Enchantment.

    SUMMARY RESULT: Recommended. The MOSFET R-R provides higher charging voltage and thus resting battery voltage will be higher by roughly 1/2 volt. This inexpensive mod plus using a lithium battery (they have higher voltages than lead-acid batteries) will help with crisp, authoritative starts and longer cranking time before starting rpm slows.

    One source for this part:
    https://www.ebay.com/p/16037701654
    (or search using the below part number)

    VOLTAGE STUDY RESULTS

    Stock R-R SH640KA 8.4091 F
    With lithium battery, after sitting weeks, key-off voltage was 13.32
    Key-on voltage during fuel pump pressurization, no headlight was 13.16
    Key-on voltage after fuel pump pressurization, no headlight was 13.20
    Key-on voltage during fuel pump pressurization, with headlight was 13.02
    Key-on voltage after fuel pump pressurization, with headlight was 13.04
    Cranking voltage with a long-cranking start, headlight on, could drop voltage to ~11
    (most of the time the bikes starts, BAM! fast)
    Cranking voltage just before in immediate-responding start was ~12.5
    Idling voltage was about 13.2 and after 20 seconds charge time climbed to 13.4
    Voltage would drop from 13.4 to 13.2 when rev'd above idle, an unexpected result. (Regulator clipping? FI current demand with respect to clipped voltage?)

    MOSFET R-R (unmarked - on the box SF-021-006035)
    I did not do an extended charge with the MOSFET R-R, so key-on voltages might have been slightly higher with the new R-R.
    Key-off voltage was 13.22 after many starts with the stock R-R
    Key-on voltages were about the same as with the stock R-R.
    Starting voltages were also about the same.
    The differences were slightly higher idling voltage with a steeper voltage climb with respect to rpm raised moderately off idle. Revving in general produces a voltage rise instead of a drop, up to clipping off at ~13.9V

    BACKGROUND
    I wasn't having problems with the stock R-R on my 2019 related to low voltage from poor grounding or oxidized connector contacts, and my wiring harness seems good. There was no reason other than curiosity behind fitting a MOSFET R-R. I had in setup silicone greased every electrical connector and every ground, and both battery terminals. When I noticed low cranking voltage, I chucked the heavy lead-acid battery for a lithium battery (Shorai LFX14L2-BS12, 14Ah, 210 CCA).

    What problems I did have with starting were not voltage-related, but from the FI having some kind of transient parameter problem (momentary lapse of reason). This pretty much always during hot starts. I had to learn that any time the bike would not fire right off, instead of cranking away, to turn the key off and back on again.

    With electric start only and FI, one should take care to assure good voltage. I added to my headlight cowling an SPST switch on the low beam to reduce key-on, pre-start load... if I ever needed to.

    The result of fitting the MOSFET I suspect will make an already good situation better More voltage is better? Worse? Thunderbutt reports 'better', but I'd have a hard time knowing for sure given no problems. If anything positive or negative surfaces related to this latest mod, I'll let you all know :thumb
  2. Thunderbutt

    Thunderbutt Been here awhile

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    Thanks for posting your well documented results. You have shown us how much the MOSFET R R can improve or at least benefit our bikes charging system.
    I learned long ago that electronic ignitions as well as EFI systems perform much better with the higher voltage rates. It might also prevent some of our members from having to do the walk of shame due to a low voltage battery.
    Tanx again!
    motobene likes this.
  3. motobene

    motobene Motoing for 51 years Supporter

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    Had a bit of time over coffee this morning so I edited the MOSFET results posting to make it more comprehensive.
  4. Trail Runner

    Trail Runner Been here awhile

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    HELP! Leaving in the morning on a trip. 2017 Beta 500 rrs running fine yesterday but now I get nothing when I turn the key on. No lights, no FI starting, nothing. All I have done is change air filter today and add dielectric grease to outside of electrical connections. Battery is showing 13.7 . Any suggestions at all?
  5. shortman

    shortman Beta 500 RS, X-Trainer 250 Supporter

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    Check those connectors. Sometimes the grease can prevent it from making a connection. Check your battery terminals. Maybe they are loose.
  6. Trail Runner

    Trail Runner Been here awhile

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    Terminals are good, rechecking all connections and fuses again.
  7. Trail Runner

    Trail Runner Been here awhile

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    Looks like I will have to ride the WR, good to have options!
  8. Trail Runner

    Trail Runner Been here awhile

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    Well I can’t say I’m not disappointed. I have been prepping my Beta 500rrs for a 4 day trip and have made some changes over the last few weeks. One of the first things I did was add a over sized fuel tank to help with range. I decided on a Cush hub rear wheel and installed that with a new rear tire. I made the R/R change and got an increase in idling volts. I wanted more lighting and some protection for my gps etc. so I added a fairing / tower and 2 Baja Designs squadrons up front. Last a dash mounted volt meter/ charging port and my Zumo XT. Bike has run and tested well until yesterday. I prepped by adding a little dielectric grease Outside connection and replaced my air filter. So I turn the key on and Nothing, no noise, no light up, no dash, not a peep. She ran fine the day before, so only changes were air filter, dielectric grease and charged battery on tender. All fuses good ( checked twice), all connections look good, battery showing 13.7. After hours of checking with no success the Beta will spend this trip sitting on my lift. The old Yamaha WR is loaded, gps switched back…… I will need to address the Beta on return, any suggestions will be greatly appreciated.
    Cheers!
  9. NoelJ

    NoelJ Long timer

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    Absolutely nothing when you turn the key on = incomplete circuit or totally dead battery. After all that fiddling by the headstock, I'd start at the ignition switch with a multimeter looking for voltage. It's getting interrupted. There's a wiring diagram in this thread that will help you think it through. 90% likely to be something simple, and something you did!
  10. motobene

    motobene Motoing for 51 years Supporter

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    Sucks to be hard up against a trip and have something requiring more diagnostic time then you had. No power at all is something big, even if it is from something little!

    I recently diagnosed a bad connection on the odometer circuit. The connector was among all the ones greased in 2019. The odo worked for months, then quit and I was too lazy to diagnose it. It wasn't until this year that I did, and I was expecting to find something more major. Assume the simplest things first is always a good rule, however, so I pulled the connector apart and put it back together. It felt a little loose so I bent the male terminals slightly and had to fiddle with it. That's all it was! A very low voltage connection so no tendency to mini-arc across a poor connection. I suspect the problem was 'perfect' male-to-female terminal alignment with insufficient clamping by a female terminal.
  11. Trail Runner

    Trail Runner Been here awhile

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    Update on 2017 500rrs, after chasing my tail for hours the Beta is back up and going. I still have not solved the mystery but it’s time for some check rides. I was getting no power through the switch, had power at connector to switch and switch checkout ok. Thinking it might be a battery issue I plugged in my air pump to the battery pigtail to put a load on battery. Ran the pump for a short time and saw no big change in battery. Turned the key and heard things come back to life?? Bike is running fine and so far I have not had a reoccurrence. Maybe someone here might have an idea.
  12. shortman

    shortman Beta 500 RS, X-Trainer 250 Supporter

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    I think the act of unplugging / plugging the switch connector fixed it... Just as @motobene said with his speed O cable..... It's always the little things that seem to get ya...
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  13. Pipeman

    Pipeman Been here awhile Supporter

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    Probably going to replace this left side radiator, sucks it's the first thing to hit when lack of rider skill comes into play ! radiator.jpg
  14. motobene

    motobene Motoing for 51 years Supporter

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    Epoxy on some pull tabs, or carefully drill an tap some threaded holes (say, three). Make up a slide hammer to impact pull the curve back out close enough. If the radiator doesn't leak after the repair you're golden until the next crash! :pynd

    A new radiator will just be a big target for a repeat :1drink
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  15. shortman

    shortman Beta 500 RS, X-Trainer 250 Supporter

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    Send to ICW radiators and have him fix it... He does fantastic work!

    ICW Radiators.JPG
    Buildzall, motobene and NoelJ like this.
  16. Pipeman

    Pipeman Been here awhile Supporter

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    Both excellent ideas ! I already ordered a new one but I will try to repair or send out the damaged one. Thank you
  17. DeadGuy

    DeadGuy Been here awhile

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    Hi, Question on the exhaust side low strap anchor point for the MoJave Bags.

    Is it just around the frame? Was thinking about same spot, but only about 3-4 mm from strap to exhaust pipe from inside the frame. No issues with heat on the strap? Did you use heat tape on the pipe in that location?

    My 2020 390 may have less clearance than your 2021 430. Thks
  18. EricNew2NM

    EricNew2NM Adventurer

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    Yes, just around the frame. No heat tape, no issues.
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  19. DeadGuy

    DeadGuy Been here awhile

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    Thank you. Looks like the frame/pipe clearance are the same on the 2020 390 and 2021 430, prior to 2020 I think they are different.
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  20. motobene

    motobene Motoing for 51 years Supporter

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    Way up in this thread you will find the little steel doohickey I fabricated to for sure keep the strap away from header pipe heat under sustained loading riding with low cooling scenarios.

    Was the part really necessary for the Mosko strap? Don’t know because I never melted one.