cylinder #1 cutting out

[905teg]

I just picked up a gsf400 with 38,000kms on it and it's got 2 issues.

issue #1
I rode it for 10kms and it ran ok, get it up to 100km/h and then slowed down, as soon as I came to a stop it died. The bike will start again with some throttle but will stall as soon as you let off the throttle. I checked the exhaust and found cylinder #1 cold, #2 warm/hot and #3 & #4 hot. So the bike is running on 1 possibly 2 cylinders after 10kms.

I searched and think it might be the carbs. I dropped it off at another shop to diagnose so hopefully its nothing major.

What are the possibilities?

issue #2

The bike also hesitates in 2nd gear between 3-7k rpm. I can select 2nd fine and it doesn't jump out of gear, I just get a ruff acceleration at that rpm. If I take first to a higher rpm before shifting to 2nd, I don't feel this hesitation.

could this be a carb issue? 2nd gear issue? or something else?

[gixxer]

If the bike has okay compressien, there are two possibilities.  Fuel or ignition. 
Try to spray some "easy startgas" into the carb of the sylindre that does not run.  If that sylinder starts to fire, its an carb issue. If there is no response, it is probalby an ignition issue.  Replace sparkplugs/sparkplugwires.

[greatmoorred]

My guess would be carb' issues. I think most people on this board have had trouble with them.
A new set of plugs would help too. And check your tank for rust and general crap in the bottom.
I find that if mine has had a long lay off it tends to run like crap for a few days, until it gets back into the spirit of things 

[mademiriam]

my guess would be carb issues as well... but then thats the easy answer on any carburated bike. Once the carbs have been given a good cleaning, and maybe the petcock and fuel strainer too, you can see if the problem persists.
I don't know how good shops are in your area... but I'd be mighty careful what you let them do.

[905teg]

Thanks for the input

A little more information about the bike

When I first picked up the bike I rode 10kms before it stalled. I towed it back to the shop that safetied the bike, they said they looked into the issue but I know it sat there for a week with nothing done. So I tell the shop to F*#k off and not touch the bike so I can take it to another shop. I pick up the bike and they say that they had a "quick" look at the bike and installed new spark plugs. They said its probably the cdi acting up if it happens agian. From searching this site, cdi's either work or dont work.

I take the bike and try to ride it home when approximately 10kms again the bike stalls. Try to start it again, only starts when giving it some throttle. check the exhaust and cyl #1 is cold 2,3&4 are hot.

I'm waiting for this other shop to give me a report on the bike, hopefully today! (they said they would try to get it in Monday)

This site has alot of great information, I almost wish that I took the bike home and diagnosed the issue myself.

I'll post again when the shop call me with an update

[simon.h]

Also make sure your vacuum hose to the petcock isn't leaking and is attached.  I was testing my bike without the tank on the other day and was frustrated that it was only running on three cylinders till I realized and plugged the vacuum line with a finger whereupon it picked right up.
 -Simon

[905teg]

Ok I have the worst luck with these shops.

I leave the bike for 3 days at another shop and finally get a call back. He says he rode the bike for 45mins and it hasn't stalled on him once. Says all 4 cylinders are firing fine and can't duplicate the issue. He says that he did feel 2nd gear jerk and said its the 2nd gear on its way out. So basically he can't diagnose the bike until it starts acting up.

I get to the shop today and look at my bike, I notice that the trip odometer has only moved 2-3kms (45mins bullshit). I don't know what's wrong with these shops, don't they want to make money. I want to get this bike on the road and enjoy Toronto's short riding season.

I got there just before closing, so I told them don't worry about diagnosing the problem I will just pick it up tomorrow and fix it myself.

I really don't have the time and experience but I would rather try myself with some tools, manual and this forum.

So i need as much advice possible diagnosing this problem.

keep the tips/help coming!


I have owned this bike less than 2 weeks and it has been such a headache.

[mademiriam]

ya, don't be surprised that what the shops are like, at least in my experience, so it's not just you.
You'll learn a lot trying it yourself, and while I know nothing about the B400 there's a few gurus here who I'm sure could help you with the specific issues.
Personally I'd take the bike home,
clean the carbs
check the spark plugs
check that all the hoses to the carb and petcock are connected properly...
and then try it again, that would get some of the easy issues out of the way, thats how I'd approach it anyway.
Let us know how it goes!

[905teg]

I picked up my bike and made it home with no stalling issues I have put about 30kms and it won't act up (wtf). Nothing has been done to the bike at now it runs without stalling.

It still has the jerking/hesitation in 2nd gear.

Should I start looking for things or leave it until it acts up?

[interfuse]

I think both of your issues are carb related... are you actually in T.O.? I'm right downtown if you want someone to look at it... but I'm crazy busy right now cuz I'm getting married in 23 days... I've got a GOOD mechanic too if you want his info.

[905teg]

I think both of your issues are carb related... are you actually in T.O.? I'm right downtown if you want someone to look at it... but I'm crazy busy right now cuz I'm getting married in 23 days... I've got a GOOD mechanic too if you want his info.

I live in Mississauga. Right now I would rather play around with the bike myself than see another shop. I'm sure if your recommending him, he's knows his stuff. If I get into something that's beyond my mechanical ability I'll have to take it to him. (pm me his info)

My 2nd issue with the jerking/hesitation feels to harsh to be just a crab issue. I am going to take the carbs out just to see what they look like and clean them if necessary. I have already adjusted the clutch tension and that didn't help. I read a post where you spent 3 hours before getting it right, maybe I just haven't set it right although I set the play at 4mm.

[interfuse]

If you're not already a member join up on gtamotorcycle.com pm kneedragger88. He's the only person I trust with my bike... straight shooter. He will pickup and drop off your bike and last I had work done it was at $25 or $30 an hour... which is a bargooon compared to most places. He picked up my bike and brought it back a day or two later... Do a search on gtamotorcyle nothing but stellar reviews.

I think my clutch is toast... it's been nothing but problems for me this year. But I can't really justify fixing it this year... :(

[905teg]

thanks interfuse, I emailed kneedrager88 on GTAM

So I've been riding the bike overs 100kms now and it has not cut out once. My guess here is that the bike was not ridden by the previous owner and had old/bad gas. When I picked up the bike there was very little gas in the tank, but did not at reserve. I have added 5 liters of gas, so I'm guessing it was bad gas causing the stalling.

[PitterB4]

If it does it again, I'd bet on a brittle plug wire making intermittent contact to the plug boot.  Or as was also suggested, you could have a problem with the vac hose where it connects to the #1 carb. 

Good luck!

[mademiriam]

If you feel that fuel may have been it...which could be, or as others here think carb issues, and you don't want to take them off right now. You could burn some Seafoam through it (available at Carquest), it's snakeoil and I always wonder if it REALLY does work, but for $8 you don't have much to loose. If there's been bad fuel in the bike, when you get around the cleaning the carbs I'd do the petcock too it doesn't take but a minute and is nice to know that at least it's working and clean.