Gsx250e regulator bogs down bike issue

[ukjules]

GSX 250e 1980
Cuts out after 2m every time .

I have had this same issue before which took me an age to sort. It ended up being a poor earth on the regulator assembly and in the end the actual regulator.

Consider the earth on the regulator plate solved.

The coincidence is that it seems the regulator is used as a replacement is now faulty ? Note also it was one I had for my gs550e , bought cheaply and never used. I managed to squeeze it into the GSX.

Suspect regulator because :
Charging test with good battery:
Battery off - 12.93
Ignition on - 12.60
Tickover - 13.8
3k revs - 13.8 or less
5k revs - 13.8

However when I leave to run for same sort of time it takes to big down after 2 miles , I noted voltage on battery jumped to 14.4 volts and bike shut off.

So could it be that this cheapo not specifically for the gsx is now faulty ? It must be so ?

Q) Can a faulty battery ruin a regulator ? I ask as I had a suspect battery in. I then swapped it out for a known good one (GS has same.batttery ) but as per my test it bogged down on my test whilst giving out 14.4v even with known good battery.

Q) Not knowing what regulators I can use , can anyone with same writing be used ? As indeed I did as GS one was cheaper than gsx one, which is now hard to find.
My next step is another regulator and has to be a cheaper one not a mega one for my gsx.

[Rich82GS750TZ]

I believe it was suggested to you previously to replace the R/R with a genuine Shindengen SH775.

[ukjules]

Can we forget the expensive option ! I stated I need a normal regulator not one for hundreds of pounds on my 250. My GS has a normal one that lasted 5 years so far.

Also the question stands with the analysis and for general info. Do you agree it is the regulator ? An odd coincidence after 6 months but possible.

Can anyone see a reason why this regulator would not work ?( Below eBay) I am thinking electronically would say this do something different to an original ? More voltage ?

https://www.ebay.co.uk/itm/Regulator-Rectifier-For-for-Suzuki-GS750E-KATAN-1980-1983-GSX750-KATAN-1980-/165237689860?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=710-127635-2958-0

[ukjules]

This is like the original. Madly small .

https://www.ebay.co.uk/itm/Regulator-JMP-For-Suzuki-GSX-250-E-1980-1981-/144416808539?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=710-127635-2958-0

[ukjules]

And this from a supplier in UK 70£
different shape.

https://www.wemoto.com/bikes/suzuki/gsx_250_ex/81/picture/regulator_rectifier

[Brendan W]

Is that a lead acid battery? 13 Volts resting looks more like a gel type?
Have you measured the + and - drops between the regulator output and batt + and reg earth and batt - ?
You could charge the battery, disconnect the regulator and run for a few miles and see what happens.
The battery should give plenty of miles without the R/R.
R/R can fail with a dead short internally which could be temperature related.

[ukjules]

Yes a very old lead acid battery was / is the original in it. The battery has for years been suspect but it works when all else is working . I.e when i put in the gs550. Just that I don't trust it .....as sometimes won't start bike. But never caused current issues alone.
BUT remember I have swapped the batteries and you are right the stats are with the known good gel battery ! So with a known perfect gel battery I got those stats AND it still bogged down or when stood I saw it jump after 7 mins to 14.4v and stop bike .....
it seems to be exactly the same issue as before . This where for months it was fine using this old RR that for some reason I kept ... From 6 years ago.

I'll have to get my notes out re tests for RR, but I am so sure that like last time it checks fine until possibly hot.

Logic says it has to be a coincidence and RR is faulty.
I will do the RR tests but notes not here where I am with bike.

[ukjules]

I also intend to buy this. The cheapest possible RR that if I put on bullet connections wil fit but is for a newer gsx model. My original was small like this not like the GS 550 one in now. Without my bike folders I am lost as to the technicalities but I see no reason why this should not work .......

https://carlightbulb.com/products/rectifier-regulator-for-suzuki-gsx250-gsx400-katana-gj76a-gk77a-1991-1992-generic

[Brendan W]

At that price I can see the attraction. I got my 775 from a local Polaris dealer before the prices went crazy. At the time I suspected the old R/R had fried my stator but as it turned out someone had wired it up inside the generator cover with bullet connectors and two of the phase wires had fried and were shorting to the case. At the time the local scrapyard gave me a bag of six used Suzuki regulators for free. Take them he said, maybe one works, they're all rubbish anyway.
The reason so many recommend the 775 is that it is a series regulator rather than the original shunt type.
The benefit is that when the battery is charged back up the 775 switches off whereas the original shunt type keeps on banging away at full chat and that extra energy is dumped back into the stator.
Over time this can damage the stator and they are expensive to replace. It's not black and white. Many members here have had no issues with shunt type regulators.
Avoid bullet connections. Spade if you have to or see if you can get a matching plug for that regulator.

[Nessism]

First off, a weak or malfunctioning R/R won't cause the bike to bog down and die, other than if the battery is discharged. I suggest you remove the battery, charge it using a trickle charger for a number of hours, then have it load tested for health. Most auto parts stores (in the USA anyway) will load test a battery for free. Or, if the battery is very old, just replace it now, and do a charging system check again. 13.8V is not horrible, and the bike should get down the road fairly decently at this level. Also realize, if the battery is bad and/or discharged, the R/R charge voltage will be low. On my bike, with a SH775, if the battery is discharged, the charge rate is 14.0V, but with a properly charged battery, it's 14.4 or 14.5V.

[fastbysuzuki]

I have a sh775 for sale in the items for sale on this site it’s in the uk used and tested ok on my bike

[ukjules]

I have 2 battery's
1- lead acid - suspect but works in GS but does go flat if left for a time. Let's ignore this one as for all tests I use the gel battery !

1 - gel - absolutely perfect works fine on gs550

Assume all batteries are always trickle charged ! And fully charged. I have lead acid ride on mower batteries that are 15 years old. I try to keep them well and seem to be able to do so with simple techniques.

The gel battery which is perfect on the gs550 is boggin down again when on the gsx.i swapped them as the same was happening on my old lead acid battery.
Incredibly the same issue as before which I fixed due to a bad earth on the RR plate assembly on the bike and swapping out the regulator (for another old one)
This worked fine until bike has been stood for months and I tried to run it .

it is a series RR bought for my GS550 but jammed in to the GSX. Remember it has worked fine for 3 months before I parked up the bike for winter.

The old problem was exactly the same a sudden RR gone bad and the poor earthing to the frame.

[ukjules]

And Assume that after the bike bogs down with the good gel battery fully charged , I put same battery back into GS 550 and will start bike and run forever perfectly .

WHere is best to put the earth wire from RR ?

[ukjules]

Update and final fix:

as we know the original issue was bogging down after a mile or so.

I had had the carburettors off many times but this had nothing to do with it in the end. Nor timing , plugs etc. . I had changed the pickups block connectors to spade connectors too.

still had the bogging down. changed the suspect battery to no avail.

after changing the regulator twice (for cheapo ones ) and making sure it's Earth was better than it is standard on a vibrating metal plate it still started to labour / bog down again at times in my 3 mile test runs.

I then tested the coils on a bench. now these coils you can't remove the ht lead and there are block connectors to join the loom. now testing primary and secondary windings (learnt off here or internet how to) I noticed I got sporadic results on primary (I have analysis if anyone wants it) I cut off both connector boxes as looked mildly corroded (40 years old) put on spade connectors and bingo good firm results. mildly out of spec but we all know it will still go.

so wired back in coils and never bogged down again. runs like a dream.

also note to test with new RR I used a 12£ RR off the net (but for bike). not missed a beat yet. Will inform when that goes but will keep it in. I never bought one of those mega ones even for my GS. (being broke al the time )

so I now forever suspect old block connectors. (as all know I am the worst ever electrical person)

cheers for help on this guy's. took me a year to sort this one as bench testing the coils was so sporadic due to the block connectors and I could not find any spare coil to test with.

[ukjules]

I will add I had also suspected the tank , breather , vacuum , petrol tap blocked hose ..... but none of these were the culprit.

although who knows it could have been a bit of each ?