Hey I'm a bit frustrated right now so pardon me being for being emo..... So I was riding my bike home from work because I've been using the hawk every day so I can fix my car. Anyway I was at a high R.P.M. in 6th gear on the freeway and it started to break up. It lost power and I kinda sounded like one piston was stronger than the other but both were firing.... The break up was sorta random because I would nail the throttle when I was in town and it wouldn't fail on me but then I was able to get on a good length of straight road I was in 5th gear I believe and then it happened again. It's not over heating at all but when I twist the throttle all the way when the issue happens it's not responsive at all and when I push the clutch in it doesn't die when the rpms comes down like 30 to 45 seconds it starts firing correctly again...... Could it possibly be an intermittent main jet possibly having random debris and lodging and dis lodging???? I was going to pull the carbs off and clean the jets while I trace a coolant leak under the carbs because there is a decent noticeable smell in that area. She has 43.000-ish miles on her and a full black widow exhaust on her. Black widow said it doesn't need to have the jets changed. When I can I'm going to check the spark plugs and should I check the timing chain as well?? Also another slight issue is when I first warm her up and I'm moving at low speed like 15 to 25mph and in 1rst gear she hiccups sorta like it misfires where it feels like it stalls a piston and feels like it wants to lock up but it doesn't. if I'm in 2nd or 3rd it's fine and once it gets to operating temp it doesn't do it at all. I also have manual cam chain tensioners also. This problem was happening before I put the tensioners in. I know this sounds like a bunch of issues but I want to get all of this out and not multiple messages. Please I need some advice on any of the issues.... she still runs good but I have gremlins and it's really beating me down. This is the worst week of my life with the engine breaking up on me and needing to fix my car asap... I can't have both my machines down........ Sorry if I'm typing a novel here. I'll understand if no one answers back because I'm messaging all these problems and the message I post is droning on. Thank you in advance for anyone that gives me advice I really will be grateful for this. I just need something to go right... Oh also could the ECM be going bad? Okay that was my last question.

 

High RPM in 6th, hope you have a working relationship with LEO's. Joking aside.
A little history of the bike might be helpful.
Has the tank or carbs been off prior to the start of the symptoms?
sounds fuel/air related. Check the petcock. See if it flows fuel when vacuum is applied. Other possibilities, but start there.

 

No the carbs were not. I will also check that as well. I took the carbs off to replace the intake boots about 4 months ago. It runs really well it just happened Thursday morning out of nowhere....

 

I had a similar problem and it turned out it was a slight tear in one carb diaphragm. Ran fine in mid-range then stumbled badly at high rpm. You would have to pull the carbs and lift out the diaphragms to check this, so maybe it's not the first thing you want to test. Mine had this problem at 56k miles.

 

Okay I'll do that as well. It may be the battery because my vfr800 when I had it kinda did the same thing. This problem is not consistent though. When I was in 5th gear going to the freeway it started to do it but then went away. I went at a higher r.p.m. and it was hit or miss I was thinking about this for a day or 2. The battery was also flat about 9 months ago and somehow I got it to charge. I believe it may be a damaged cell. The battery is a duraboost cycle gear special in other words? A cheeky cheap battery... I'm getting another one for now and if it doesn't happen again I'll let you all know. I want to get a yuasa agm because they are a great battery.

 

Also one other thing I need to ask? I have a coolant smell under the carbs. Are there any lines I should check if the carbs have preheat? Also if it coming from the overflow tank it should be the bottom line because I don't see any residue on the top one. How often do the overflow tanks last before they get brittle?? That's if they do.

 

I don't know why it's not letting me reply back to you that or I'm stupid but I didn't check the diaphragm yet and I will tomorrow for sure.because it will be 4th of July and I have it off. I have a set of sliders coming from eBay just because they were cheap anyway. How likely would it be the diaphragm? Also should I get a petcock rebuild kit just in case? One of my friends said it also could be the strainer for the petcock as well. I also need to know the rear vacuum line is on it for it also. Is that okay or should I block it off and find another vacuum line?? Sorry if I'm asking you so many questions...

 

The "other possibilities" include carb diaphragms. Do the simple things first. Check to see if the vacuum line to the petcock is good and attached to the correct port on the petcock. Unless you have a setup for balancing the carbs on permanently, there will be only one vac line from the base of the rear carb to the petcock. Yes there is coolant going to the carbs. Good or bad, I removed those lines on mine. I do live in a warm to very warm climate, so YMMV. I had to replace the coolant expansion tank on my bike. It had a crack in the molding seam on the bottom of the tank. If you decide to rebuild the petcock, use only the original Honda part.

 

Sorry for the late update I had some health issues. So I checked the diaphragms and it didn't have any tears. I did take the choke cable assembly out and oiled the cables and noticed a little wear on the cylinder plugers.i also changed the spark plugs and it's still having that issue. I tested it and under load at 7000rpm in 5th gear it starts acting like it's running out of gas then dies. I pulled over and pulled the choke and it started up again.

 

Symptoms suggest a fuel delivery issue.

 

I agree with Xeris. Maybe a float bowl not floating (or bent) or a chunk of dirt in the fuel line (even stuck partway into the carb itself. This must be frustrating, but I think you're doing all the right things.

 

I found the problem. I wanted to check the petcock and to drain the gas and I sucked on the vacuum side of it and nothing but gas fumes.. so I was a little dazed LoL. I took the petcock out and yup? The diaphragm has a tear. So I'm going to order another and give you all an update. I know now this was the issue

 

Congratulations!

 

I'm happy to let you all know I installed the rebuild kit and tested it on the freeway last night and she's back the way she was which is a huge relief. Without a doubt it was the petcock. I went though all gears and rpm and no problem now. Thank you guys for helping me. It means a lot. If anyone has this trouble this may help. Hope you all had a great weekend.