Project The Second Fizzer

Yep you're right on the money there. Couple of hours charge now I'm getting around 13.8V at idle. Probably a bit high, I expect it to drop back when the battery settles a bit because I basically pulled it straight off the charger and threw it in.

In other news I went into the carbies again (it's a fizzer thing!) and checked all the jets. Everything's correct and clear so we're good there. The only issue I found was that something still isn't right between Blair's Litetek seals and my floats. It's happened before, but I'm puzzled why I am getting compression failure. All the other seals in other areas are fine, but all four of these are buggered. No issue though, I threw in the keyster ones instead and reassembled for now.



I took her for a ride, she goes really well up to around 10-12K and then bogs again. I played with the choke and the idle to see if making it richer then leaner made a difference but it didn't. So that leaves one thing left - spark. Everything else seems fine, must have a plug or two that aren't pulling their weight. The plug leads are still relatively new from last time I changed them and I know the coils go OK so let's see what I find there next. Wish me luck!

 

Yeh, this is the correct (smaller set). I still have the larger set. Last time Blair wanted me to measure the diameter of the opening and let him know so he could check against his records, but unfortunately I don't have anything precise enough to measure it (my dodgey digital caliper is cheap and nasty). I'll have to get something better and do it at some stage though.

 

No I didn't, but then again I didn't have an issue with the keyster ones they just went straight in...?

I'll have to move onto float heights next. It feels really lean so maybe its something to do with that, or blocked in the bottom of the tank or something...

Also has anyone heard the GT250R prior to 2010 uses the BDST26 carburetor, the same as the FZR? I stumbled across a thread (lost it now) that suggested that was the case...? If so this could be a seriously important piece of info...

I wonder if needles/jets/emulsion could be sourced through hyosung.... I checked the service manual and it's definitely BDS26 but a double as opposed to inline 4...

 

So I tried a few things today. New plugs, changed the EXUP motor out to my spare and started snipping HT leads back. It is better, around 12K now, but doesn't want to go much higher. Still feels hindered...

I suppose next step is to make the needles richer... or simply swap them out for the keyster ones and tubes. Starting to mess with a lot of things now it's going to be hard to put the finger on one cause.

 

Nah not yet, It is on my list of things, I wanted to try what I thought were the more obvious issues first. It certainly seems to go well up to 12K now... I need to push it harder to see what it does.

I do have a question about that process though, is it a matter of getting a hose and marking a particular length on it to line up with the marking on the carburetor bowl? Otherwise I imagine the variability as to how hard you "pull" the hose would influence accuracy. The second mark is around 9mm above that line (can't remember exactly I need to look it up again).

 

Thanks mate I did see that in another thread my question is how long is your piece of hose? Did you mark the first position relative to the end that is attached to the carb? Because I'm sure you could slide that up and down with your thumb and gain or lose a few mm on the measurement (also it looks like your hose is semi pinched, is this an issue?).

Just trying to get a feel for potential variables.

 

Ah ok great thanks for the clarification. Hopefully i have the right size hose (will check my brake bleeder kit) and I'll do that this evening.

The bloody thing sounds pretty bullet proof now it's quite annoying to not have it 100% perfect

 

Hmm so playing around today I think I've found the source of the problem - the fuel pump. The fuel filter seems to be running 1/4 full or less which I think is strange, you'd think the fuel filter would run full. The previous universal one I had did. Checking the suction the fuel pump sometimes seems to work and sometimes doesn't... it's weird. I thought there was air in the system so I cleared it and thought everything was working fine... but the pump didn't seem to be running when the bike was running. Also it seemed to only prime part of the time.

It sorta makes sense if there is an intermittent issue here that under mid to full load the fuel supply would be starved if the fuel pump isn't working properly and/or is sucking 3/4 air and 1/4 fuel.

I'm going to try a chinese pump (see how it goes) and see if that rectifies the issue. Any recommendations? I've seen some for about $25, but I don't know how long they last.

 

Yeh that's the one I bought... see what it does. If it fixes the problem then I know it's that for sure. I haven't done the fuel levels yet as I'm not sure the carbies are filling up correctly

I was actually gearing up to do them after I was testing the fuel circuit heh...