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Gremlins

Posted: Tue May 11, 2021 11:11 am
by zoidberg
So the new to me Falco is having some teething problems. It runs absolutely perfect u til you wind the throttle on up to about 8k then all power dies. The dash goes off etc. A moment later it will come back to life as if nothing happened.

The charging display on the dash shows 12.7v which I'm not happy about.

Is there a particular part that fails on these? I'm going to test the stator and reg/rec later. It has a recent lithium battery on it which is fully charged.

Re: Gremlins

Posted: Tue May 11, 2021 11:18 am
by zoidberg
13.3v idle charging at battery after start up and responds well to load lights etc. Battery voltage drops to 11.6 when firing up. So that all seems good

Re: Gremlins

Posted: Wed May 12, 2021 2:59 pm
by mangocrazy
It wouldn't be something that would be affected by vibes at a perticular rpm, would it? Perhaps wiring to the main fuse or the main fuse itself, or even the tip over switch under the seat?

Re: Gremlins

Posted: Wed May 12, 2021 4:35 pm
by zoidberg
I never thought to check the tip sensor. Would that result in a complete shut down of electrical power?

Re: Gremlins

Posted: Wed May 12, 2021 9:59 pm
by Falcopops
zoidberg wrote:
Wed May 12, 2021 4:35 pm
I never thought to check the tip sensor. Would that result in a complete shut down of electrical power?
It will, but I thought you need to cycle the key off and on again to get a restart

Re: Gremlins

Posted: Wed May 12, 2021 10:05 pm
by zoidberg
The first time it happened I did that. The second time it came back life life as quickly as it went off.

Re: Gremlins

Posted: Sun May 16, 2021 7:24 am
by katie1
Had a similar issue on a GSXR - turned out the wiring was melting due to a dodgy connector. Could be the fabled melting connector issue?

Re: Gremlins

Posted: Sun May 16, 2021 8:28 am
by zoidberg
Thanks for the reply. Which connection would that be? I checked the brown connection to the reg/rec and it looks ok. I did go get myself some contact cleaner to go through everything I just haven't had chance yet.

Re: Gremlins

Posted: Mon May 17, 2021 8:23 am
by wrenched
That sounds v familiar. The first thing I found I had to do on buying my RST (a good while ago now) was to replace the regulator. After some testing and reading around I concluded that an Aprilia original just wasn't worth the risk and fitted a Honda VTR regulator. Its produced a nice constant 14v ever since. Previous owner, as I suspect many others do, had it practically permanently wired to an Optimate but I don't find that necessary. It can stand for say a month without charging but batteries dont last long. On average Ive struggled to get better than two years.

Re: Gremlins

Posted: Mon May 17, 2021 1:59 pm
by zoidberg
Thanks. Is the regulator plug and play from a VTR?

Re: Gremlins

Posted: Mon May 17, 2021 3:36 pm
by katie1
zoidberg wrote:
Sun May 16, 2021 8:28 am
Thanks for the reply. Which connection would that be? I checked the brown connection to the reg/rec and it looks ok. I did go get myself some contact cleaner to go through everything I just haven't had chance yet.
Yep, the brown one. Definitely worth checking to see if it is undamaged

Re: Gremlins

Posted: Tue May 18, 2021 5:50 am
by wrenched
Hi, I don't honestly recall if I had to do some soldering to fit the VTR regulator but judging by the non standard tape around it I'd say wasnt pnp. I posted that as mine ran at something around 13-ish volts which actually went up slightly under load but it clearly wasnt keeping the battery up. I think the batt on the Fut is pretty small for an engine that starter-unfriendly added to which it lies half horizontally! Your rev-related symptoms imply something else going on so more investigation needed. Ironically I jumped on my Ducati 851 yesterday which hadn't been ridden yet this year and a mile down the road it cut out dead,!!! Due for MoT safety test this morning so I wheeled it out 99% confident it would be fine🤬!

Re: Gremlins

Posted: Tue May 18, 2021 6:06 am
by wrenched
The fog of time/age is clearing a bit and I now remember that the hole separation of the VTR regulator us different do I made an adapter plate to fit it to the Futura.

Re: Gremlins

Posted: Tue May 18, 2021 6:07 pm
by zoidberg
Sorted. Well seems to be. I cleaned all connections and secured the tip sensor and all seems well so far

Re: Gremlins

Posted: Wed May 19, 2021 11:35 am
by mangocrazy
Glad to hear that. On the subject of reg/recs I've been a big fan of Shindengen MOSFET R/Rs since swapping to one on my old (1988) VFR750. That had been through two R/Rs and a combination of moving the R/R to a location in the airflow and fitting the MOSFET unit seems to have cured the problem.

I'm not sure what type of R/R is fitted to Falco/Futura/Mille models but I suspect it will be one of the older shunt type units. Apparently now MOSFET is yesterday's news, and an even better type has been developed, but as the MOSFET type works for me, I've not investigated it.