'83 shadow VT500c problems!!!!

[Tobias]

Oh, I forgot to mention, I changed the spark plugs and replaced the ignition coils. Coils were testing bad and spark was very weak.

[7s1amma7]

If its a flow issue taking it out may help. I noticed with my quad that in the summer it was staying open the whole time after it warmed up so why even risk it restricting or completely blocking the flow if it never needed to close in warm temps.

I bet that stop leak has your radiator all effed up and you cant push enough coolant through it fast enough to cool it. Or your pump isnt moving it fast enough. If its your radiator taking the tstat out wont help. If its the pump taking the tstat out will help.

[Tobias]

Well I'm not certain what was in the radiator, I just know that I took some gunk out of it. Guess I'm gonna go bust down the radiator and the thermostat housing again. Might go see if the bike shop down the road can pressure out the system before I do that, though. I can get it there easily enough. I'll be back later, folks. =D

[Earthling789]

You've got flow restricted somewhere... and my money is on the water pump not being able to push enough flow at speed like is should... You may need a new water pump?

[corvin]

Maybe coolig system is not your problem.Her is my story:
This winter changed pistonrings on my VT500.
Get almost new carb set. Cleaned them, mounted,my gasline from tank to T-jiont was rotted.Changed the line(leave a bit longer than needed)
started the bike easy,syncronyzed the carbs.Engine work like Swiss watch.No overheating,just like yours,when temp.gauge pass half way to red the fan kicked,cooled for about 30sec then turned off.thats ok
Tryed the bike in my street,low speed,go thru every gear,everything is ok.
this sunday go out to try on open road,then it started to heat up,ride it for one hour,then decided to try it a bit harder,go up to 130km/h.
Then noticed ,the bike performed bad,no power,at 8k rpm stopped responding on throttle.When I got home coolant seeping from expansion bowl.
So deciced to check what is happening,when I started to remove the gastank noticed the twisted(broken)new gasline.The rubber was ok when mounted,from engine heat the rubberhose softened and broke,restricting the fuel suply,not completly,enough to leave the engine running werry lean.Fixed the line,now it is running better then before.
So my advice check fuel suply,clean the carbs.
Maybe it is stupid but worked for me.

[Tobias]

Just got back from Heyser Cycle and the guy there said that (yes, you may laugh at me) I have the wrong oil in the bike. I did an oil change and the manual said 5-30 or some such so I ran down to the auto parts store and got some. I didn't know there was a difference in auto oil and bike oil. Now I do. $60 later I have bike oil and a new filter. Gonna grab lunch and go change it and see what happens.

The guy said that at the higher rpms the oil I have in it basically isn't doing all it should and something about the viscosity of the two types of oil being different (I took automotive back in '94 so I don't remember all the rules and properties of viscosity) and causing it to not lubricate as it should at the higher rpms. If this is my issue, I'm going to kick myself down the length of my street and back again. Twice. If it's not the issue, I'm back to messing with the radiator and thermostat/housing. I'll probably try running without a thermostat first go to see if that points to the pump or the radiator as Slamma said. More to come.

Earthling - If it's flow restriction, it's either in the heads or the radiator. There was gunk in both but I flushed everything out (my GF would say excessively) and had all the lines removed and gone over to assure they're clear. however, with the radiator, the hose pushed water through it easily once I got the obstruction out. It was coming out the other end as fast as it was going in. If there's a restriction anywhere, it would be in the heads. I didn't have a proper snake tool and was only able to snake in there about 4-6". Everything seemed to flow fine afterward, but it wasn't a "proper" snaking. Gonna check the oil theory after I grab a sandwich and see how that works out.

Again, thanks to everyone taking the time to offer tips and suggestions. <3
More to come as I play the trial and error game. *headdesk*

[7s1amma7]

clutch will start slipping to if you have the wrong oil. correct weight and make sure whatever you use is jaso ma certified. Hope you get it figured out.

[Tobias]

Ok, so I have a bad ground on the cooling fan. Sometimes it comes on and goes off as it's supposed to, sometimes it doesn't come on. No worries, I'll just trace back for the bad ground. It's ground because when I touch the wire connector to the frame the fan turns on. No big deal, just annoying. Wasn't going, then when I let it cool and had it idling, it worked again perfectly. Deceitful little thing! Anyway, that's not an issue, I'll fix that.

I changed the oil to the right kind and stuck a new filter on. Same issue. Was doing great until about 50mph. Threw it in OD and had it at 55 and the temperature went up again. Blew a little coolant out of the overflow/reserve but not much as I stopped the bike immediately on hitting red.

Corvin - Thank you. The carbs were just redone and I replaced the fuel line because it rotted out on me as well. Whoever had this thing before me did not take good care of it. The issue I had with my line was kinking as it turned to go to the T connector. I just added extra line and made it turn gently around the hose coming from the top of the rear valve cover and that fixed the kinking. I have power at high RPMs and I have good response from the handle. It was acting similarly to yours for similar reasons but that's been done. I appreciate your input. No input is stupid. I've learned that some of the "dumb" things that people said either triggered a realization in myself or someone else or turned out to be pretty close. I'll double check that tomorrow just in case. Thank you!

Slamma - I had heard that so when I realized I had the wrong oil in there, I changed it immediately. Which reminds me, I have a milk jug full of oil I have to get to a service station soon. Thank you!

So with having found gunk in the radiator and cooling system before and having so many people on here and otherwise tell me it's restricted flow, that's where I'm going to focus my attention tomorrow. First off I'm going to see if there's anything else in the radiator and maybe replace it just to be sure. If that doesn't knock it off, I'll probably try and find something I can snake through the heads to clean out the passages without removing the engine again. If that fails, full engine removal, tear down the heads/scrub passages, replace the water pump (just because) and then use it for target practice if it still won't stay cool after all that. Sound about right?

Thanks to everyone posting and checking back, I appreciate everyone's input. I'll post up more as it goes and check back here to see if any other suggestions pop up.

[Tobias]

So I'm on my bike now with a new (used) radiator. Short burst at 55 in OD and it maintained temperature so I got on the highway and it crept up juuuuuust to the red. I'm stopped at a gas station and the Coolant was mildly bubbling in the reservoir.

The old radiator had very fast flow and this one had trouble getting water from the hose through it at a high rate. Fan is doing all right so far. Could it have been that the coolant was going through the old radiator too quickly? The radiator that I have on now came from a bike that "ran great" before the cycle salvage guy pulled it and gave it to me.

So it's doing better but it's not perfect. Any other suggestions? I'll hop back on here when I get home. It held the right temp for a bit but then went up again. I'm so frustrated!!!

[Tobias]

Another question: Is there a good tool to say, snake through the cooling channels in the heads without removing the heads? Do I need to just remove the heads? I don't have a torque wrench to get them exactly back to spec.

I don't understand how one radiator flows through super fast from the hose and the other builds back pressure and sprays me but both work similarly well. The one with back pressure seemed to do very slightly better than the one that flowed freely.

I'm starting to think that even though the water pump checked out - no broken or bent fins, spun freely, etc - that I might need to try a new water pump in there. If I replace the water pump, I think that will make for the only part aside from the thermostat housing that I've replaced on the cooling system.