87 mufflers

[Docjava]

May need to replace my muffler cans for my 1987 Venture. The previous owner knocked out the baffles. A little louder than normal but not too bad, however, will this affect the engine performance??

[capn eddie]

Dennis it won't affect it , in fact it should breath a little better. I replaced my mufflers with some jardine rumblers and it runs much better and i didn't have to rejet. So you should be fine.

[Docjava]

Thanks, I hear you and that could save me some $$. The bike runs great, however, I do have a low end slugish problem. Stumbles on light throttle and the occational light cracking type backfire until I give more throttle. Didnt know if the open cans could cause or out of sink carbs. I was going to have the carbs sinked soon, dont know if they ever have been done.

[Venturous Randy]

Thanks, I hear you and that could save me some $$. The bike runs great, however, I do have a low end slugish problem. Stumbles on light throttle and the occational light cracking type backfire until I give more throttle. Didnt know if the open cans could cause or out of sink carbs. I was going to have the carbs sinked soon, dont know if they ever have been done.

 

Carb syncing should be done on ocassion, even if the bike is running fine. It is easy to do and if you check around, you may find a local member that will be delighted to do it for you. If you wanted to come toward Johnson City, I can do it for you. I also suggest that you check your carb diaphragms and your fuel mixture settings. All of this is in here and if you have not figured it out yet, this will be the best $12 you will ever spend on your bike by joining this group.

RandyA

[ctraylor]

Make sure someone hasn't drilled holes in the air box. I had the same problem and taped up the holes and the problem was gone.

[skydoc_17]

Hey Doc,

Because the back pressure has been reduced by the drilling of the stock exhaust mufflers,

You will need a slight change in your riding style to keep the motor from stumbling in the lower RPM range. Don't "chug around" in the 2500 RPM range when shifting gears, run the RPMs up to 4000 plus before shifting. When running thru town in a reduced gear like third or forth, keep the RPMs at a steady 3500 plus RPMs. This runs the Carbs. in the "Main Jet Circuit" exclusively, and cuts out the idle circuit completely. It sounds to me you may have a small amount of blockage in the Idle Circuit of your Carbs. ( 900 RPMs to 2500 RPMs) As RandyA said, a Carb. Sync., and a fresh set of plugs, would at least give you a baseline for Maint. on your bike. Have a good close look at the Air Filter, if it is the paper one, and it looks loaded up, and you don't know how old it is, REPLACE IT with either another paper filter or spend the bucks and get the K&N unit and never buy another filter for your scoot again. To minimize problems with the Carbs., install a new fuel filter as well. A few ounces of Seafoam in a full tank of gas, and regular riding will clear up that pesky Carb. blockage problem unless you chug around in 5th gear at 45 MPH and ride your bike once every two weeks. These bikes LOVE RPMs and love to be ridden regularly. These engines were "tuned" from the factory as far as the intake (air box) Carbs. and exhausts (Mufflers) goes, If one or more things are changed in this system, then some changes have to be made in riding style, or the mods become more of an annoyance than anything else for everyday riding. Because these Carbs. run rich by nature, the needle shim mod might be helpful. If the low RPM stumble persists, I have a set of MKII VR stock mufflers and the needle shim mod kit if you are interested. It sounds like lunch with Randy might be just the ticket to get your bike tuned up and running better, he knows his stuff.

Earl

Earl

[jasonm.]

These are very "flexible" engines. Low end torque w/ higher rpm HP. Sometimes I like riding mine at 2500-3000rpm in 5th because I know I am keeping the pilots cleared out. And it gets me 45mpg. Once a Venture is tuned properly they can run in 5th , smooth from 2000rpm on up. I took me a while to get mine to run this perfect. And after 20+ years on it. NOW, It's the best it has ever ran. An EGA machine(many dyno shops have) can solve and answer many issues. But they must use the exhaust "adapter" to read each cylinder independently. See adapter made from 6mm carb sync brass fitting and copper pipe.

[elmicko]

Carb syncing should be done on ocassion, even if the bike is running fine. It is easy to do and if you check around, you may find a local member that will be delighted to do it for you. If you wanted to come toward Johnson City, I can do it for you. I also suggest that you check your carb diaphragms and your fuel mixture settings. All of this is in here and if you have not figured it out yet, this will be the best $12 you will ever spend on your bike by joining this group.

RandyA

Randy did a heck of a job getting my bike running smooth last winter. He won't take money, but does like to be fed.