Bogging down at 7.5k RPM

[TopCatGr58]

Hey there Jumper,

Well, at least that mystery is solved, you're running 79 carbs, which in itself is just fine. Just make sure you run those carb vent tubes up and are kept open, not clogged, possibly even a filtered cap on them if you're running Indy filters instead of the stock box. Many folks have had problems with poor performance, and came to find out their vents were clogged, either at the carb, the tubes going up from the vent ports, or even on the carb box where they attached, either plugged=wrong model/year carb box for carbs, or just crud/corroded closed. The new intakes will help considerably IF they were leaking to begin with. Good luck!
T.C.

[thumperjsa]

Thanks TC.

The new intakes are in UPSs hands and I should have them on Friday. Unless they come in the morning though I won't get to work her until next week because I need to be out of town next weekend.

I can't wait to get the carbs back on and get out for some riding again.

[thumperjsa]

Update

Got my intakes put on last night. So bike is up and running now. Now I am getting heat on all 4 exhaust manifolds instead of 3. Pickup is better but still not pull my arms out if their sockets yet. I still think I am missing something. It will get up to 7k RPM pretty quick but won't go more. I guess I can live with that rather than make it a parts bike from an exploded engine. After I took it out on the road for a bit the engine had lost power and I thought I had done something wrong. Fortunate for me (and unfortunate as well) I put on clear fuel filters and noticed one was not getting fuel to it. Turned out I put a kink in the hose. Undid the kink and I was back up and running. Funny how these bikes don't like running on 2 cylinders.

One other item I had to note. I opened up the air box and guess what was not in there. No air filter. I had planned to go to K&N pod filters but after waiting 1.5 months, I think the guy I was buying them off of on E-Bay has decided to keep my money and not send them. I e-mailed him several times and was getting responses in the begining and now, no responses. So I left him negative feedback and will see if he responds to that.

I also noticed that there is only one screw holding the upper and lower half of the airbox together so I will have to figure out how to close it up better and plug up the holes that are passed the air filter. So I guess I will be buying a regular air filter and fixing the air box next.

[thumperjsa]

Well, this weekend, thanx to a lot of reading on this site and tips, I decided to get brave on my bike again.

I decided to withdraw from putting pod air filters on and got a different airbox. My old one had so many holes in it from missing screws, covers and other parts that I felt it better to buy another off of Ebay.

I could not pull the old airbox off without removing the carbs. While I had the carbs off, I remembered the problem I was having with the #2 carb running a bit rich and thinking that was part of the problem of the engine bogging down as I tried to break the 7k RPM barrier. I pulled the #2 carb lower cover off and measured the floats. One was at 22 mm the other at 24 mm. According to what I read, if the floats are too low, it will cause the cylinder to run rich. I did not think the 2 mm and 4 mm difference would matter but I decided to adjust it. So I adjusted both so they were right about 26mm. I put the bike back together and even decided to put the crankcase pipe back to the airbox. Before when I had this hose hooked up, the bike would bog down to almost no power, but I said, what they hey and hook it all up.

I took the bike out and it had no more bogging down issues. Got to 8k with no issue and still wanted to go more. I decided to back off rather than chance having to pick up engine parts.

I took the bike out for the first time in about a month this morning and she is running better than ever. I have one problem to fix though when I get it back home. I am getting a little bit of a fuel leak from what looks like one of the hoses from the tank. I assume it to be the way I ran the hoses. Ever since I put on in linne fuel filters, it seems everytime I put the bike together, I have something causing fuel starvation or fuel leaking since I put them in. Got to keep toying with that till I figure out the best way to run the hoses.

I do have a request. One of the petcocks I have does not have a filter or the tubes (reserve tube may be important for long rides). I was wondering if anyone can part with these parts.

Thanks for all the help I have found on this board. About the only good thing the PO of this bike really gave me besides a challenge.

[nashville_bill]

I solved a problem with the fuel lines bending too far and limiting fuel flow by putting a spring over the lines, where they bend back up, close to the petcocks. The springs, that are just larger than the hose O.D., will not let the hoses crimp.

[thumperjsa]

Interesting idea about springs. That seems like it would work. I assume you used thinner wire ones so the hoses will still flex the hose a little.

[TopCatGr58]

Hey Thumper,

That's great!!! Don't know if you've seen this diagram or one similar, it shows a fairly large inline fuel filter, but the idea is similar, you can run your lines across/around the inlets to reduce the sharp angles, and either come back to the bank of carbs on the same side as the petcock, or even cross over and put them on the other fitting on the other side of the bike!?

Those springs can be obtained at local hardware stores, yes, you will want fairly flexible ones!

[thumperjsa]

Thanx TC.
I found something similiar looking through the carb modifications as well. I had not seen the one you posted though.

By the way TC, I hope you are feeling better now.

I took my tank and seat off when I got home tonight to figure out the fuel leak. I think one of the hoses were not tight on the fuel filter. I am going to get some more fuel line and try to put it together like the drawing.

I also had to trace out some electrical gremlins. My turning signals were not working on the way home. Turned out to be two issues. A little loose on the connection under the tank. But then the lift blinkers would not work. Saw the lights dim when I tried to use it. It turned out the the lamp connection inside the rear bulb was a little loose and was rubbing on the side of the bulb holder. Can you say run 12v to ground...

Got to love these bikes. Also does not help that a PO changed out the rears which should be a single wire to a double wire like the fronts should be. I also decided to power up the front signal second filament since I was running without a running light on the front.

[nashville_bill]

Yes, the springs are very thin and flexible.



I need to find a way to make these images smaller.