Bike not running properly
 

Sorry for wall of text, just thought it would be easier this way instead of answering 99999 questions later.

So today I was going for a ride and had been driving around the area for 1 hour or so and set course for home. While rolling down a hill, I could suddenly feel the bike did a small "bump" or something, no sound, I just felt it in the bike, same feeling as when you get a really loud backfire all the way into the headers.

I tought it was just that, I had just let up the throttle, so I didn't think about it until I reached the bottom of the hill and applied the throttle again, then I noticed that the bike ran really crappy, lagging and coughing, so I pulled over to figure out what just happened.

The bike idled just fine, as soon as I applied throttle, it would cough and just die off. I managed to get it going like this and crawled my way in 1st gear at 3k rpm to try to get home (was only about 1km or 3/4 miles out) didn't want to push it all the way as it was all uphill. Managed to get like 1/8 mile in snail pace until I felt another "backfire" and then it just stalled out on me.

I could still start it like nothing had happened and it idled fine, it just died off as soon as I touched the throttle, so I had to push it the rest of the way. Did get a good cardio session tho...

So now it sits in my garage, starts an idles fine, cant get it to rev above 2k rpms unless I pull the choke lever/button thing, then I can get it up to 5-6k barely and then it just spits and coughs.

I have checked:

Spark plugs, they look ok and works
Fuel tap(?) under the tank, inspected vacuum membrane, looks fine
Rear carb, checked vacuum membrane, looks fine


Messed about with the carb pistons a bit to see if one of them would slide easier/faster than the other, they seem to work exactly the same, think that means the front carb vacuum membrane should be fine as well.

I also put some more gas in the tank just to make sure it wasn't close to empty and the fuel light had failed or something.
Vacuum lines also seem fine.


Has anyone ever experienced something like this?
Running out of ideas here, it really seems like there is a fuel/air related problem because of that choke thing.

Appreciate all suggestions and help, I'm quite new to this whole bike world.

Do you have manual or (stock) auto CCTs

Did the vacuum hose that leads to the petcock fall off? The petcock is vacuum operated. There should be a vacuum hose the leads from underneath the carbs to the back of the petcock, not to the bottom of the petcock. This could be possible fuel starvation.

What about your R/R (Regulator/Rectifier). Is it stock? Is it finned? This could cause these issues as well if it is on its way out. Check the R/R's connector for burnt wires. Are you handy with a multimeter?

Also, it might be a CCT (Cam Chain Tensioner) that let go and the timing chain jumped a couple teeth and the timing is off. But usually stock CCT's don't break and then keep a little tension. FYI, this is an interference engine, so your pistons will hit the valves if the timing is way off.

The CCT has already been swapped out by the previous owner, so that sould be ok.
All vacuum hoses were in place, petcock is the one under the tank, right?
One hose was broken off, it went straight into the tank and out under the bike, looked like it was just for ventilation or something, also from the looks of it, that hose had been off for a long time already, will try to find out what it's for tomorrow.

'99-'00 has the petcock attached to the tank. '01-'05 has the petcock attached to the frame.

What about your R/R? Look on the subframe on the bike's right side (just underneath and behind your right butt cheek, while sitting on the bike obviously).

RR looks fine as well, no crispy wires or sockets or anything. It's just flat on top, not finned, so it's probably the stock one.

That's the one I got

From experience I can tell you that should be on your short list of "change sooner rather than later". May not be your problem now but it WILL be eventually and usually at the worst possible moment, while destroying most of your charging system.
Plus don't make the mistake of just using the finned version in place of your non-finned version. At the very least go mosfet, do a search, there is quite a bit of info on here. May even be a stickie, if my memory serves me correctly.
Good luck with your bike.

I didn't know the RR was a weak spot, my bike has 34k on it (about 20k miles I think), should I worry about this anytime soon?

How many years does it have on it and yes.

Just a thought, but what if the previous owner didn't set the tension correctly on your manual CCT's and the timing did in fact jump a couple teeth? However, before tearing into your engine, check the simple things first. Follow the K.I.S.S. rule. Make sure your petcock is actually working correctly. Once you checked out your fuel system, lift the tank and open your airbox and take a look and make sure everything looks okay. Once you checked your fuel and air, then check the spark. Do you know how to use a multimeter?

The petcock itself should have three hoses on it the two larger hoses are fuel supply tho the carbs, the tiny one is the vacuum supply to the diaphragm to allow fuel to flow. There are two other hoses that attach directly to the tank, the larger one is the fuel overflow from the filler area of the tank, the smaller is the fuel tank atmospheric vent that allows outside air to enter the tank as fuel is consumed.

Just to clarify, there are four nipples on the petcock. The two large ones (1/4" if I recall correctly) are for the fuel lines to each of the carbs.

There are two small nipples (1/8" if I recall correctly). There is one that points down, and this nipple vents to atmosphere. No hose attached to it.

There is one on the back of the petcock that points dirrectly to the back of the bike. This nipple gets the vacuum line to the carb.

Okay, so I gave the petcock e little blowjob and fuel poured out everywhere, so that's obviously working just fine.
I also switched the spark plugs front to back, but it made no difference whatsoever. The rear cylinder is dead, that's why I tried switching the plugs.

Next step should be cleaning the carbs I guess, how do you guys do it quick and easy?
I have been a car guy mostly (injection) and the previous bike I had would just run forever, so I haven't really got a lot of experience with this kind of maintenance.

Did you try switching the ignition coils to see if the problem switches to the front?

I just did.

Then I reconnected the fuel tank to fill up the carbs because I have been testing a bit without a fuel supply. It turns over, starts spluttering and coughing.... and voilà, it's alive!

I don't know what happened or how it just came to, but it seems to run just fine now. Will take it for a short test ride to see if it's actually okay now or if it was just 20 seconds of luck.

PVLIR ;)


https://www.superhawkforum.com/forum...es-pics-22048/

Don't know what that means but I found the cause of all this misery.
Fuel indicator light is dead... I hav run it empty.
Will check tomorrow if it's the LED itself or the tank sensor. Does anyone know if there is a way to get a proper fuel gauge on this bike? It's a 98mod Firestorm (EU model)

Well done - its gets easier and you've learnt a bit about the bike underneath the tank:-)

Is the fuel tank sensor plugged into the connector near the battery. Otherwise undo 3 bolts retaining the clocks to access the back and replace the bulbs.

And sort out manual CCTs and R/R sooner rather than later!

The sensor is plugged in, will try to short out the plug to see if the light comes on.
CCT's were done not long before I bought the bike a few weeks ago.
As for the R/R I don't really know what is good and bad. I read that the stock Honda one is pretty much crap, so what should I buy? I have been on a Ebay shopping spree lately, so why stop now?

Mosfet FH020AA R/R > www.vtr1000.org ? View topic - what have you done to your "bike" today

Look at the part number on the stock r/r, "sh1t". I'm sure the manufacturer knew it was poop when they put it on the bike.

I got a bit lost in all the options for mosfet RR's, they seem to come in all shapes and prices, would someone be a gent and post a link to a RR that will work fine odna maybe even plug in directly to the wiring loom?

As a reminder, my bike is a 1998 Firestorm.

https://www.superhawkforum.com/forum...27/#post397120

Got a mosfet RR for an SP-2 from a guy on the norwegian Craigslist'ish type site. Set me back a grand (150 dollars maybe, not sure of the currency rate atm), so I hope this works forever.
Also, I have plans about painting the bike Candy Cobalt Blue, does anyone here have a Hawk og Storm with an awesome paintjob? Just curious, need inspiration for my winter project.