Question from the most non-mechanical guy you know!

[MikeAstringer]

I picked my bike up yesterday from my buddy's shop. If you haven't read my prior threads my buddy owns a shop where he builds custom hot rods and hot rod boats. He's built a few bikes in his time and offered to help me with all of the changes I wanted to make to mine.

One of the things we did was get rid of the stock pipes for a set of V&H pipes. Prior to changing the pipes I experienced a bit of popping (not much) but I've read others here complain about VT1100s of my vintage (mine is a 96') about popping. Yesterday the bike was not just popping but full on backfiring, BAD! My buddy adjusted the carbs to the point where it doesn't do it at idle but it's doing it bad when I'm riding and let off on the throddle. Additionally the bike doesn't seem to have the same power it did previously. This was never a race bike but it could put you back in your seat if you got on it before. It no longer feels that way.

When I ordered the pipes I also ordered the jet kit they recommended.

I'm going to do some riding this weekend (if the weather holds out) then bring it back to my buddy's shop on Monday before I leave on business travel so he can try to figure it out. Like I said, my buddy is a good mechanic but he's a car and boat mechanic.

Any suggestions on where to start? When I tell you it's bad - and loud - that is not over pleading my case. As soon as I let of the throddle to slow down POP POP POP POP POP POP.

[Floyd Dolin]

Mike, when you upgraded your exhaust system the air flow to fuel ratio usually is a little out of whack. Your bike may be running too rich or too lean. If too rich, you're going to have fouled plugs and some black smoke coming out of the exhaust. If too lean, then you're going to experience the backfiring popping noise on decel. Based ONLY upon the information you gave, I suspect you are running too lean. Did you install the jet kit that came with your exhaust upgrade? Let us know what your buddy finds out so that all of us can learn.

[MikeAstringer]

Thanks Floyd. We did install the jet kit. There is no black smoke so running lean is probably the answer. Frankly my buddy is a good car/boat mechanic but this might be a mission for the Honda dealer. I'm going to leave it with him this week but he's not a bike mechanic and I'm not convinced he'll figure it out.

[Schattenreiter]

Can't say for sure but I have read others on here say they experienced the same thing because of the exhaust gaskets. Did you use new ones when you installed the pipes? Are the bolts that hold them on torqued properly? Just a thought.

[xrayr]

Air fuel mixture screw....

[Floyd Dolin]

Originally Posted by MikeAstringer

Thanks Floyd. We did install the jet kit. There is no black smoke so running lean is probably the answer. Frankly my buddy is a good car/boat mechanic but this might be a mission for the Honda dealer. I'm going to leave it with him this week but he's not a bike mechanic and I'm not convinced he'll figure it out.

Mike, the dealer mechanics will surely square it away; however, they'll reach deep iinto your pocket as well.

Originally Posted by Schattenreiter

Can't say for sure but I have read others on here say they experienced the same thing because of the exhaust gaskets. Did you use new ones when you installed the pipes? Are the bolts that hold them on torqued properly? Just a thought.

Another good point.

[MikeB]

Clearly an overly lean condition (which you can verify by checking the plugs) but I'm not sure I'd hold out too much hope for getting it fixed by a dealer. They are used to dealing with OEM setups, not re-piped and rejetted engines.

Are you confident your buddy installed the jet kit? It sure sounds like he omitted that little detail.

This is really something you should do yourself. When you mess with either intake or exhaust getting the jetting right is a lot of trial-and-error, and it may require multiple visits ($$!) to the carb innards.

BTW, if you pull the plugs and find dry, white deposits (as I think you will) it could be hazardous to the piston crowns to ride it until the condition is corrected, whether it's a leak at the flanges or wrong jetting.

["Captain D"]

I have just a thought, a mechanic is a mechanic!!!
Whether automotive, marine, truck or motorcycle mechanic...
Good Luck,
Dennis

[Lukeduck]

Sounds like you are on a boat as many others have been. Most manage to get it sorted through jetting. Jetting and exhaust leaks seem to cover most of the problems. Take the time and/or money to get it properly sorted so you can be a happy camper. Have fun.

[siryan]

Im in the same predicament as you are right now bought a used shadow with v&h pipes and k&n filter and bike pops on decel really bad have it rejetted by a local bike shop took them a month and when they gave it to me its acting the same way.