Das nightmare has returned lol

[jagco1]

Thanks for the tip! I might try that.

Update after more troubleshooting:

- If I start her up for a minute and rev it between 1-3k, then shut her off, I can twist the throttle to all the way open and see white fumes coming out of all four velocity stacks

- Also, sometimes when I rev to 2-3k and twist the throttle back down to closed, the revs stay up around 1.5k. And no it's not the throttle linkage because I looked and both things were sitting on the idle screw :ummm:

Haha any help is appreciated!

I run wd-40 through each black hose / vent hose 1 at a time motor running.

Motor will bog down a little, try this on each carb if your using the stock vmax carbs. And see if this help, I have dun the p-shooting thing to. I hate taking the carbs off to clean them.

This suck to pull the carbs. I been there so many times. I leave my gas drain hose longer to hang over the motor to catch in a cup. I hate gas run stains in the motor paint.

 

[Chopcor]

Not trying to make waves here but wouldn't it make sense to sell/trade these carbs for a complete stock carb/airbox setup that you can actually enjoy instead of messing with constantly? Bolt them on, fire it up, and get the V-boost rush we all love! :biglaugh:

 

[DigitalArts]

I was within seconds of accepting Sean's generous offer but I ended up thinking I was up for the challenge.

Part of me wants to keep these cabs for 135 potential hp and ram air (pointless but cool) and the possibility of buying a 1500 motor when mine blows up one day.

BUT realistically I probably should trade them... just seems more daunting than rebuilding these myself since I'd have to take off the crankcase vent, whole intake and linkage etc.

 

[DigitalArts]

Also, just brought it out for a late night ride and realized that there is a connection between how hard I run it vs how long till it stalls.

It all makes sense.

If I flog it at 7k for a quarter mile it will run perfectly for 100 yards or so then decline in rpm and die.

On the contrary, it lasts for 3x as long before it becomes difficult to accelerate if I run at 2-3k rpm.

So! With that, I'm thinking either the fuel bowls are overflowing/emptying or there is an electrical problem that can't keep up with the bike.

 

[95spfldmax]

Thanks for the tip! I might try that.

Update after more troubleshooting:

- If I start her up for a minute and rev it between 1-3k, then shut her off, I can twist the throttle to all the way open and see white fumes coming out of all four velocity stacks

- Also, sometimes when I rev to 2-3k and twist the throttle back down to closed, the revs stay up around 1.5k. And no it's not the throttle linkage because I looked and both things were sitting on the idle screw :ummm:

Haha any help is appreciated!

This is usually a symptom of a vacuum leak (leaning out)

 

[DigitalArts]

This is usually a symptom of a vacuum leak (leaning out)

Can you elaborate on this?

How do I troubleshoot?

I just re-confirmed, it shuts down after riding a certain amount of time (about a mile or two) then needs to sit and wait for a few mins to start again

 

[marsmax85]

Dude your a nut I live most likely 50 miles from you . Are you guy having some type of heat wave over there cause it's fricken witches tit cold here .. lol sounds to me your carbs are running out of gas .

 

[DigitalArts]

Dude your a nut I live most likely 50 miles from you . Are you guy having some type of heat wave over there cause it's fricken witches tit cold here .. lol sounds to me your carbs are running out of gas .

I think you're right about the carbs. And haha it's my only transportation right now so I'm stuck with it

I had to ride in rain and snow the other night

 

[Traumahawk]

How about a piece of advice? If its your only transportation.....it needs to be dependable. You might want to reconsider the offer from Sean.

 

[marsmax85]

Hope you have some type of bonnets or some type of protection for stacks .One grain of sand goes down into carbs you could be buying a 1500 sooner then you want .

 

[DigitalArts]

How about a piece of advice? If its your only transportation.....it needs to be dependable. You might want to reconsider the offer from Sean.

I really would like to but I'm not sure I can disassemble everything correctly or in a short enough amount of time that I won't be left without transportation during the swap.

It also sounds like the problem is probably getting fuel to the bowls now too, so I'm going to try and solve this since it would need to be done either way

 

[Traumahawk]

I really would like to but I'm not sure I can disassemble everything correctly or in a short enough amount of time that I won't be left without transportation during the swap.

It also sounds like the problem is probably getting fuel to the bowls now too, so I'm going to try and solve this since it would need to be done either way

You can be running lean due to A/F screws being incorrectly set. Ive been reading up on the Keihns......there is a low speed, part throttle screw as well. I had also said that it sounded like you were LEAN...not getting enough fuel

When someone says fuels bowls....depending on the carbs...that is a storage area on the side of the carbs......so even if your having problems with these....you can swap carbs....and not have the same issues.

 

[Traumahawk]

http://www.keihincarbs.com/tips/gate.html

Most people on here...myself included...havent messed with 39 mm keihins...is strictly guesses. your probably better getting the carbs to someone that has experience with them.

 

[jagco1]

I'm not sure on this but if this the bike that was sold in Brentwood / MT Rainer MD....
I went to see this bike, bike was dirty and the guy could not get it to run right when I was there.

keihins carbs I have had 2 sets, Is best to take the bike to a good shop that can work on the bike/carbs together.

There are not hard to work on keihins. But kinda need to no what your doing.

There's good shop on route 1 up the street from MU Collage on the right hand side about 5 to 6 miles up from the Collage There sale bike parts, There shop is around back for service. Just pass the Burger King.


They work on fz750 i had 10 years ago for me.
I don't remember the store name, I can ask few of my friends if you need the info.

If you going try to do it your self google the carbs and check youtube for more info.

 

[blaxmax]

I have used keihins of all sizes (37,39.41) and not much adjustments needed.
How many of you guys know that he is running a LAWN MOWER battery setting on top of the velocity stacks that cover the right two carbs?:bang head:

 

[alorio1]

Sounds like your bike's carbs are going empty. Those carbs are probably gas hogs and the stock fuel pump you have one there may not be pumping 100% at it's capacity. If I had those carb on my bike with all the symptoms you have, I would change the fuel filter and buy one of these;

http://www.ebay.com/itm/23138169209...em=&sspagename=ADME:X:RTQ:MOTORS:1123&vxp=mtr


I think it puts out 4 inch pounds of continuous pressure.

 

[dannymax]

Sounds like your bike's carbs are going empty. Those carbs are probably gas hogs and the stock fuel pump you have one there may not be pumping 100% at it's capacity. If I had those carb on my bike with all the symptoms you have, I would change the fuel filter and buy one of these;

http://www.ebay.com/itm/23138169209...em=&sspagename=ADME:X:RTQ:MOTORS:1123&vxp=mtr


I think it puts out 4 inch pounds of continuous pressure.

I'm thinking the same thing....are the floats adjusted correctly?

 

[DigitalArts]

Thanks for all the input, guys. I really appreciate it.

As for the battery, I have an Apex on the way! Hahaha.

As for the carbs, if I had to guess I'd also say the main problem is that they're going empty. Though once I fix that I'm sure they will need adjusting.

As for the floats, I don't have the tool to check the float setting so I'm not entirely sure

 

[DigitalArts]

I'm not sure on this but if this the bike that was sold in Brentwood / MT Rainer MD....
I went to see this bike, bike was dirty and the guy could not get it to run right when I was there.

keihins carbs I have had 2 sets, Is best to take the bike to a good shop that can work on the bike/carbs together.

There are not hard to work on keihins. But kinda need to no what your doing.

There's good shop on route 1 up the street from MU Collage on the right hand side about 5 to 6 miles up from the Collage There sale bike parts, There shop is around back for service. Just pass the Burger King.


They work on fz750 i had 10 years ago for me.
I don't remember the store name, I can ask few of my friends if you need the info.

If you going try to do it your self google the carbs and check youtube for more info.

I would bring it there (appreciate the recommendation) but I'm barely affording the parts I need right now haha, so I'll take it on myself. Poor college student mentality haha

I wish I could convince my dad or popop to come help, both are master mechanics but they don't have much interest in helping me with a motorcycle.

So far on the list I need to do:

Battery
spark plugs
fuel filter
fuel pump
clean bowls/jets

Can someone link me to a good fuel filter?

 

[wayne z]

Have you checked the tank vent for partial blockage? That would cause the symptom of quitting after a hard run. That Spitting and backfiring on some and not all carbs sounds to me like running lean from dirty carbs though.

You can physicaly check carb sync by blocking the throttle grip partialy open and check clearence between each butterfly and venturi with a dowel or butt end of an appropiate sized drill bit. Adjust sync until all have the same feel with the same bit or dowel.

I suspect though, It won't run right until the carbs are completly dismanteled and cleaned.