98 VTR1000 Fuel/Electronics/Both?
 

Hey folks, new to the site and new to Superhawks. I picked up a '98 VTR1000, and believe everything is stock with 68,000 miles. The previous owner said it overheated on him and he didn't want to pump any more cash into it. I'm pretty sure he layed it down and got gunshy. The battery is junk and with a jump start it runs for about 15 minutes but eventually dies out and won't restart even with a jump. My multi-meter showed high (but weak) 12's for volts prior to starting, then with a jumper pack it'll start up just fine and run at about 1500 RPM showing mid 13's for volts. When I give it gas the volts drop immediatley to mid-low 12's and stay there, let off the gas, RPM back to 1500 volts back up to mid 13's. RPMs will wain and it will run rough but with some gas it will stay running until eventually it dies out and won't restart for 20-30 minutes. I removed the spring and cut the drain blocking portion out of the diaphragm so the petcock is just an on/off valve now. The symptoms occurred before and after I modified the diaphragm. Gas also leaks overnight out of the exhaust fittings at the center of the bike both before and after the diaphragm modification indicating float stickage I reckon. Wondering if stuck closed or stuck open or both could cause it to starve for fuel. Sounds like an intermittent miss while it's idling for the 15 minutes it runs too? Any ideas? I know the hydrolock situation at hand, great fun, gas in the oil and such, I'll be sure not to bend any rods. Thanks for the help.

Wow, you lost me at hey folks. Thats a lot of......words.

I'll wait for the concise post.

Welcome to Superhawkworld

Sorry about that smokinjoe, the skinny is: I can't keep it running for more than 15 mins even after modifying the petcock to be wide open and it leaks gas so much that it comes out the exhaust overnight. The things I've noticed if it helps diagnosis are in the original post. I know i have fuel issues but maybe electronic issues too? Thanks again.

No, you just hooked up the vacuum line to the wrong nipple. Not sure what words to search but it also sounds like you may have a stuck float valve. No electronics would cause anything like that.

So does the gas just flow out of the petcock freely with no vacuum? If so then my first comment was wrong

Welcome to the forum, seems you have a rough start though, don't know the whole story, but I think you should look into replacing the diaphragm in the petcock. It's known issue to cause gas leeks as well as making the bike not run correctly. use the search option and you will find plenty of info on this, it may be a very easy fix.

Where does it come out the exhaust? If it is filling the cylinder you should be real careful to avoid trying to start it: that could cause hydrolic lock which can damage the motor.

Thanks for the replies. The petcock was allowing fuel to flow originally, but for diagnosis I cut the center out of the shutoff nipple and plugged the vacuum line and capped the vacuum port on the petcock (the back side) to allow gravity to do the work. Thinking the floats aren't stopping the flow when the bowls are full, so gas fills up the cylinders and goes out the exhaust, eventually leaking out of the joints at the center of the bike. It leaked out the exhaust prior to the bypass so I knew I had to rebuild the petcock eventually. Just want to get it running for longer than 15 mins. Stuck floats=starved for gas eventually?

As Joe mentioned, you shouldn't run it in this condition until you get the petcock to work properly first, the gas should not just flow with gravity alone, the vacuum hose is there for a reason same as for the diaphragm, also it seems like the carb's need some attention as well, I would strongly recommend to at list clean them up

The float in the carb should actually float on the gas going into the carbs to stop flow of gas. I think I am right about the gas filling the cylinder so dont just go hitting the starter. It will lock up the piston and bend something major.

Really you need to replace/ rebuild the petcock and remove the carbs to free up the floats. BUT with the petcock fixed you should only get gas flow when the motor is running so you can stop the exxon valdez thing.

Sounds like a winner on all sides. Seems like most petcock rebuild kits on eBay are around $40. I'll just have to tackle one front at a time. Both outlets that come straight from the tank are breather tubes? No leak there, just curious of their purpose.

Overflow and breather - make sure they're clear by blowing them

You could even just get a whole replacement petcock for cheap 00 Honda Super Hawk VTR 1000 Fuel Petcock BH | eBay

Once you do the petcock, you just attach the vacuum line and suction to the line (you can just suck on the tube) and fuel should flow from the 2 larger tubes freely with vacuum applied.

Thanks for the link, I ordered a K&L rebuild kit for the petcock earlier today though. I've had the bike for about 2 weeks now and have a tough time trusting even a slightly used petcock. Curious about the difference in prices for r/r, from hong kong they're $20, from the US it's closer to $70. I'm thinking about the mofset installation I saw another member talk about. Worth the trouble?

Yeah you kinda have to do the RR. I had to push the bike for miles when mine went. You can use an R1 unit. They are bulletproof.

It's more along the lines of replace once, or replace once a year... ;)

It's a small difference in cost really, for me it was more an issue of time spent fixing the issue over and again...

It sounds like the running problem has nothing to do with the carbs but everything to do with battery voltage. Or maybe I missed somehing? I would get the battery/charging fixed and move to the carbs second, but that is just me.

Good luck!

This is overcharging and has probably fried the battery. Best to replace both the battery and R/R. Put the petcock back to standard. Make sure the vaccum goes back on the right place as this is a common mistake, then everything should be fine.

(:-})

I read that as "back to 1500 [rpm], volts back up to mid 13's". I'm pretty confident he did not mean 1500 volts.

Oops my mistake your right Jamie, I just re-read it. volts back up to mid 13's. Doh. Lets see what happens when he sorts the petcock out.

(:-})

Good catch Jamie, def not jammin 1500v to the toy of a battery. Waiting on the UPS man right now.

Sounds like a bad R/R to me. Different RPMs place different demands on the rectifier. It might do it's job when at light load (lower voltage and amps) but fail when it gets more amps (and heat).

tsp
My blog: Motorcycle Touring

update
 

Thanks for the insight all. I've been at it slow and steady. So far: rebuilt petcock, cleaned carbs (float shutoffs were stuck open), new R/R and a new battery. took it out for a ride and it was quite a bit more sluggish than I was hoping for, but then thanks to the TPS adjustment walkthrough (I got it right at 500 ohms magically), now this monster lifts the front wheel when going from half throttle to 3/4 throttle at 45-50 mph. it seems like it's governed at 120 mph, is this the case or is it a symptom? any way to bypass the governer? because 6th gear seems almost useless if you can't. I picked the bike up for $200 and threw another $200 at it and now it really only needs plastics. the wife wants me to sell it but it is so freaking awesome!!! Thanks again, and any feedback on the governer or if there is one on the '98 model would be great.

No there is no governor, what's your gearing?

Not sure, bone stock '98 "1000" cc. Great through gears and great throttle response until 120 mph, doesn't matter which gear I'm in when I hit that speed, it acts like an electronic governer is engaged.

First check kickstand switch. Sometimes the stand is a little loose and at a certain vibration it will disengage momentarily (killing the motor as if the kickstand were down) and then re-engage, seemingly just like a governor. You can bypass it and take it out to quickly check it off the list, or have a very easy fix.

If that's not it, next guess is airbox/carb issues.

disabled the kickstand switch, same result. Thanks for the idea, I would've never thought to check it though, easy enough test to rule it out. thinking carb tuning and sync is one of the last things I have to deal with. I did have one symptom come up that I haven't seen before though, after I first started, i put the blinker on and it was slow and dimmed the headlight on the flashes. new battery and new R/R, it starts easy, just curious if anyone ran into the same thing.

You should check the funtions/connections of the batt & rr. My buddy just had similar issues & wanted me to look at it. Popped the seat and saw that the RR was totally unplugged..

Dont rule something out just cuz you just did it. It sounds like a charging/voltage issue so check voltage while off then runnng to chk charging. Also while slightlty reved.

Usually that's an issue with the grounding, high resistance causing low voltage to the front of the bike, the cluster and all lights share the same groundpoint, so when there isn't enough for all, this happens...

Agreed, double check, then triple check...