Hello all. I'm new to your forum, and I actually found you when I Googled how to clean the carbs on my F4. Thanks to the great write-up I found here, I was finally able to complete the task!

Anyway, now that I've cleaned my carbs, I’m hoping to get some further guidance. My F4 only has 5K miles on it, and it hasn't been ridden in 7 years. The last season I rode (2006), I wasn't riding nearly as often as I used to, and I noticed issues with the throttle early in the season. Basically, the bike would fire right up and idle fine, but the bike would stall when I would give it throttle. If I keep the RPM’s up while starting, the bike runs great and I can get through the gears fine. The problem only seems to be when the bike is idling regardless of it being in neutral or not.

The issue seemed to slowly work itself out throughout that season, but being that the bike was 7 years old in 2006 and didn't get ridden that often, I figured this must be a carburetor issue. So, I planned to clean the carbs the beginning of the next riding season since I knew I would have issues again after sitting another winter.

Well, life got busy in 2007, and cleaning the carbs was low on the priority list, so I just decided not to ride that year. Then, 1 year turned into 7! So here we are. I finally got time to pull my carbs out last weekend, and to my surprise everything was clean. I pulled the jets out and those were squeaky clean as well. This was a bit of a disappointment because I had a feeling that this cleaning wasn't going to solve my issue. I cleaned everything up regardless, soaked the jets, put everything back together, topped off the coolant, change the oil and filter, put in fresh gas, and fired it up. Unfortunately, as I suspected, my original issue was still there.

So now what? I’m up for pulling the bike apart and trying some different things, but I don’t know what to chase next. Any advice or guidance would be much appreciated. I’ll also post in the General Tech area. Thanks in advance… Dave

 

Check fuel filter, fuel pump? I bypassed the pump and it was the reason my bike kept shutting off with throttle.

 

Check fuel filter, fuel pump? I bypassed the pump and it was the reason my bike kept shutting off with throttle.

 

Thanks for the quick reply. Out of curiosity, was your bike running well under higher RPMs, and only shutting off with initial throttle? It just seems so strange to me that the bike runs great if I can get the RPMs up. I would think that if it was a fuel issue, I would have issues with higher RPMs since there would be a higher demand for fuel. I didn't realize you could bypass the pump... I'll have to look into this a little more.

 

initially my bike was not having any issues at all and slowly over time developed what appeared to be like a misfire. over time it got worsebut mainly after riding on the freeway when I would come to a stop and go to take off again it would stall. on the freeway it would run fine but even that got worse where I started to notice the lack of poweruntil eventually the bike stalled out on the freeway at speed.I had had the same problem with a different bike however the gauges stop working and it was a rectifier. In this case you had already been replaced at all the electrics sceneto be in good working order.the progression from good like misfire to very bad took about1 month. I let the bikes it for a while and it would start up but as soon as I Road its would die this. Lasted a few weeks until I had some time I check the plugs it looks good air filter was fine put some seafoam in the carbslast but not least check the pumpI put a new filter on it and all the hoses were replaced the pump acted as if it was working however I don't think it was putting out enough fuel. So for 3 weeks my bike was almost unable to start and would die as soon as I gave it throttle and after I took the pump off it ran great I'll be ordering a new pump shortly but in the meantime all the problems it was causing are gone motor sounds perfectly smooth and there is no signs of any misfire exceleration is greatand smooth through the entire power band. My next step was to dismantle the carbs however like I said before the bike ran great so I didn't think the carbs were the main issue and I was correct they just weren't getting enough fuel. And I think it takes more fuel to get the bike moving then it does even at higher RPM's to keep the bike moving that's why there's more hesitation at lower rpm I'm not a mechanic so its just my thought hope it helps

 

Hmmm... your issue sounds a bit different from mine. My bike runs great with the exception of initial throttle. I can fix the issue by keeping the idle WAY up, but I know that's not a real fix. I'm not opposed to trying the pump bypass, but I'll have to do a little more research on how that's done. I've also been told that the next logical step is to try new plugs, so I might give that a shot as well.

 

I had already checked my plugs and they look to be in tip top conditionkeeping the RPM's up I believe relates to a higher current being generated so you're right it could be electrical in nature. I was given advice once to put a multimeter on the battery and Rev the throttle if it showed more then 14 volts the rectifier was likely bad if it was below 14 volts that it could be the stator both which have an impact on exceleration as well as your bike maintaining a charge.

 

Thanks... that makes me feel a little more confident. I bought the plugs last night (NGK)... just need to find some time to put them in. I'll report back with the results either way!

 

I know you arn't really displaying symptoms of this but when was the last time you synced your carbs? Hopefully after you cleaned them right . TBH I don't think its your filter or pump; seems more like carbs, dirty throttle cables or crudded up plugs. I would double check the ignition timing too than as a very very very last resort check valves.

 

Update... I'm now more confused than ever!

And, thanks for the reply, CJardine. I did not sync the carbs because the carb cleaning thread led me to believe that wasn't necessary. Maybe I need to revisit that.

Anyway, I changed the plugs over the weekend, and things seemed to be a lot better. The bike fired right up, and the throttle issue seemed to be 90% fixed. Previously, I would just touch the throttle in neutral at idle and the bike would stall. Now, as long as I was slow with the throttle, all was good... not perfect, but at least ridable.

So, I let the bike idle for a few minutes and then decided to take it for a quick ride. I rolled out of the garage, popped it into 1st, slowly gave it throttle as I let out the clutch... and it died. I couldn't get it started again and eventually flooded it. I finally got it started after I let it set for awhile and started it with the throttle open, but it ran extremely rough for only a few seconds and died again. I haven't gotten it to start since.

What happened??? I tried bypassing the fuel filter and pump yesterday to rule that out, but I still couldn't get it to start. I believe it's getting fuel because it smells like the bike is getting flooded after repeated attempts to start. I've got to believe I created an ignition issue somehow by changing the plugs... seems like I solved the first problem (temporarily), but I created a new one. Should I clean up the old plugs and try those again?