fried reg/rect plug?

1982 xj650 appx 25k i've owned 1 year. when i first bought the bike occasionally the headlight would stop workign so i looked at the fuse box and it was in bad shape so i put all the fuses in "inline" holders and this resolved the problem. i've rode the bike almost everyday since then without a problem and have done nothing to it (except fluid change, safety check when i first got it) over the past month she's started acting up a bit. i think i have two problems perhaps? first, it will just bog down when i'm cruising at a steady speed (not really when accelerating). i know "bog" is vague term but the exhaust sound changes to a much deeper tone, i have to give it a lot of throttle to keep it going, and to confuse me even more it doesn't do it all the time. when this first started to happen it was only in fourth or fifth gear while cruising at a steady speed. now it has gotten progressively worse to doing this in all gears and while accelerating, not just cruising. three things seem to make it temporarily go away. 1) if i drop the clutch and let the rpms go to appx normal idle speed, the sound and power loss goes away and i can take off again...only for it to return minutes later. 2) if i hit a bump, i regain full power and the deep exhaust note disappears. 3) if i park it, and come back to it later, it's ok...for a little while. the second problem i'm having is that i recently started blowing fuses...and the only one blowing is the one to the headlight. i searched through old posts on here recently about "blowing fuses" and saw where a couple of times it was due to a bad regulator/rectifier. so today i parked her and started having a look. i knew this before but now it's really evident. the PO has done a total hackjob to the electrical system. wires just dead end, splices everywhere...it's a mess. the white plug going from the reg/rect to the harness was melted shut...i pried it loose to see the connections for the red wire completely fried/black and the white plastic melted. so, after as much background info as i could think of...where do i go from here? are the problems related? just a bad reg/rect or did something else cause that to go bad? any help would be appreciated

 

I bought an 82 750seca with all the same problems. Everywhere i look on my bike someone messed around mess being key, back to your bike tho I got a reg/rec from wisconson cycle salvage for like 10 dollars. If that conection is melted its fried. Run your bike for just a min and see how hot your reg/rec is, its not supposed to be really hot, my old one would sizzle when you spit on it. my conector was a little burnt not bad tho i cleaned it up and it still works fine. I also replaced my altinator brushes and cleaned up in there. A new battery is probably a good idea now too. the reg/rec might be messing it up, mabey im not positive about that. That might help with the elec. problems, not sure about the deep noise problem it might be part of the same thing or it could be something eles about to go out. i would check the bolts on your exhaust first who knows might be loose.

 

battery tests 12.5V with bike off. i haven't done any tests with the battery under load though.

 

try riding with the gas cap closed but not latched, there's a vent in there that might be plugged
the melted connector says heat caused by bad connections, try just putting new connectors on and see what happens, your going to have to do it anyway

 

i recently read a forum post about messing with the gas cap while the problem was occurring, just as you're suggesting. while riding and having these issues i would pull the ignition key out and open the gas cap to vent it...no change. didn't seem to help the issue. i clipped the red wire on each side of the melted plug and spliced them to bypass this bad connection...no change either. all other six connections in the voltage reg/rect plug look ok.

 

I had charging problems on my bike due to burned up connections in the rectifier/regulator plug. I cleaned them and treated them with electrical grease and they've been OK since.

I think you should clean up or replace the plug/socket regardless, but, if this were the cause of your power problem, I think you'd find that you'd be having drained battery problems as well.

 

ok, plug connections have been cleaned and greased...still no improvement. battery checks out with no load.

 

The bit about coming good when hitting a bump is intriguing......I don't suppose the battery terminals are shorting on something?

Have you tested the voltage at the terminals when running? Should be rising to 14V with increasing revs.

What do the plugs look like?

 

Do a flow test on the petcock. Disconnect from carb, use a catch can, apply suction to the little tube. Compare to "PRI".

I had a melted connection - the 3 white wires from the ALT to the REG, 2 were actually crossed inside the melted gob that was the connector. Amazingly, it didn't ruin anything and the bike still ran and charged the battery.

 

yeah, it's pretty crazy to hit a bump at sixty and your bike takes off again. wierd. just checked the battery again. 12.5v with no load. easily rises to 14v when revving. terminals are clean and tight. petcock checks out, it pours out on pri but nothing comes out when on "on" or "res". suction applied does not cause any to leak here either so petcock is good i think.

 

yeah, it's pretty crazy to hit a bump at sixty and your bike takes off again. wierd. just checked the battery again. 12.5v with no load. easily rises to 14v when revving. terminals are clean and tight. petcock checks out, it pours out on pri but nothing comes out when on "on" or "res". suction applied does not cause any to leak here either so petcock is good i think.

 

Sounds to me like the main problem is a sticky float or float needle, or something else mechanical that's blocking fuel flow.

Don't suppose you have access to a dyno, where you could recreate the problem and then tap things to see when it goes away?

 

clarification...in the first post i said drop the clutch...i meant depress the clutch lever fully so that rpms return to near idle...this would allow the bike to run right temporarily. another update, i pulled the plugs and 1,4 are real lean...whitish...2,3 are black with soot, not oil. looking more closely at the airbox to carb boots, 2,3 has a slight gap where the boot is clamped to carb body improperly, allowing unfiltered air in. 1,4 are seated and clamped properly. of course i can't blame this on the PO, i've owned the bike for a year so i guess it's time i pay my dues for overlooking things. fun fun. as far as access to a dyno, no...not even sure what that is. i'm a little new at all this...really the only things i know are what i've read on this site so i'm learning as i go. thanks for the input.

 

just did a compression check as per instructions i was given in a previous post. 1-4 are 113, 117, 115, 123 i think these are good numbers???

 

For Pennsylvania (not very high elevation), I'd say those number are a bit low. I'd expect 120 or higher for all cylinders. But, they're pretty close to each other, and not VERY low, so I don't think that's your problem.

A dynamometer (dyno) is a device that allows you to run a vehicle under load and at speed, as if it was on the road. It's used for measuring and adjusting engine management parameters, like fuel injection maps and carb jets.

Sounds like the old story of "clean the carbs, maybe replace float needles and seats, set float heights, synch carbs, etc..." is what's needed here. The plugs seem to say that the floats in 1 and 4 are too low, or the floats or float needles are sticking and preventing enough fuel from getting into the bowls, or the jets are obstructed, or maybe all three.

 

yeah, i figured i was going to have to clean them. not knowing how long it's been since they've been cleaned what would be recommended to replace as far as part within the carbs?

 

the carb issue wouldn't make me blow fuses though would it?

 

No. Probably a different problem. Which fuses are blowing?

 

i'm not sure which but it's a 10amp and when it goes so does the headlight.

 

The Melted Regulator Plug means your Charging System was overloaded.
Measure the Voltage at the Battery with the Bike running at 2,800 rpm's or above.
The Voltage reading at the Battery needs to be: +14.2V ~ 14.5V.
Any value not within that parameter indicated a Charging System problem.
( A reading of +14.8V or higher ruins the Battery )

Your Carbs need to be removed and Cleaned.
It sounds like the Diaphragms are sticking.

Bogging occurs when the FUEL Supply is insufficient or NOT sufficiently atomized.
If the Diaphragms aren't lifting, ... the Bike starves for Fuel.
Revving-up to cause them to rise feeds more Main Jet Fuel -- But, if the Emulsion Tubes are Fowled -- that extra Fuel can't Burn with Power because it fails to Mix with the air.

Inspect Alternator Brushes
Inspect Alternator Rotor
Evaluate Voltage Regulator
Clean Carbs
Refinish Carb Piston Bores

 

thanks everyone for the input, now i have a starting point.

 

Actually, it was supposed to flow pretty good with suction.
The petcock flow test doubles as the cap vent test, if you think about it.
but - on to the "clunk test" and a complete carb cleaning.

 

timetoride, thanks. i didn't know it was supposed to flow...but when i think about it that obviously makes sense. so, what does that indicate...no flow? i guess while i'm cleaning the carbs i might as well rebuild the petcock and gas cap...are these relatively easy to do. thanks again everyone.

 

I used to recommend REBUILDING the Vacuum Petcock.
I don't, anymore.

All too often I have encountered a Rebuild Kit that didn't fit and leaked.
Therefore, it is my opinion, you are better of getting a NEW Petcock.

My rationale is based on the amount of time and effort expended in rebuilding the Petcock with disappointing results; against simply refitting the New one.

 

I've had good luck just taking them apart, cleaning the internals with carb cleaner, and reassembling with a bit of silicone grease. The problems I've seen with them sticking is usually related to the same varnish and gunk from old gas the gums up the carbs.

 

All very useful but I go back to his original comment:

"if i hit a bump, i regain full power and the deep exhaust note disappears"

It must be an electrics issue!

 

Hitting a bump and having performance change seems more like a Carb problem to me.

Especially,if the Exhaust note changes.
You probably jar a stuck Diaphragm Piston to rising.

 

Sounds like poor/ dirty electrical connections. Start out looking for white powdery stuff in the plastic connectors then buy a 12 pack and sit down and clean them all.

 

I'll split the middle, clean the connectors and the carbs for good measure.

 

alright, i'm back. tomorrow, i'm ordering a manual, valve shim tool, and anything else that you guys recommend. although i probably should find the exact problem and fix it before i move on, i'm just going to go over everything i should have when i bought it. first thing i did wrong...when i took the compression test, i didn't let it warm up first...so disregard those numbers. since the consensus seems to be valve check/adjustment before any effort on the carbs, that's where i'm starting. i found a 32 blade set of feeler gauges at napa today and popped the top to have a look. first, i'm new to this...but you guys make it look easy so why not. following bigfitz52's thread on valve check/adjustment i took some measurements today. however, the set i bought has large gaps between the smaller sizes. here's what i found:
intake 1 .076mm fits-.102mm does not
intake 2 .102mm fits-.127mm does not
intake 3 .102mm fits-.127mm does not
intake 4 .102mm fits-.127mm does not
am i right in assuming that i need more feeler sizes and that #1 is definitely out of spec with 2-4 potentially out of spec based on more checking with different size feelers???
exhaust 1 .127mm fits-.152mm does not
exhaust 2 .127mm fits-.152mm does not
exhaust 3 .152mm fits-.178mm does not
exhaust 4 .127mm fits-.152mm does not
does this mean 1,2,4 are definitely out of spec and that potentially #3 is???
hopefully these clearances aren't too small to cause any damage? while i have the cover off, is there anything else i should be looking for, checking, or cleaning in general or because of the shim numbers i have?
also, i removed the carbs....going to attempt cleaning them. i'm still reading and getting organized based on what rickomatic's threads recommend. i want to be thoroughly prepared both in a knowledge and material sense before i attempt this so it may take me a bit longer than most. i'll also clean and check all electrical connections. it seems most people recommend dielectric greasing and heat sealing all connections. are there any connection points i should not do this to or are they all ok to do that to? thanks again for everyone's help.

 

Dielectric grease should be fine once you get the corrosion removed, I would avoid using hot melt glue to "seal" your connectors as this will create difficulties in getting back into them, negating their usefulness.
Another suggestion in cleaning contacts is to use a mini blaster with baking soda to remove corrosion. Simply extract the contact, clean and reinsert. Quick and cleans up easily with alcohol or contact cleaner.
Garbage Freight sells an inexpensive mini blaster for about $30.

 

I'll check that out. Thanks