2006 Suzuki Boulevard C90T Back fire

[Dan Janousek]

I purchased a brand new C90T April 26, 2006. It back fires when I let off the throttle. I have 540 miles on it. It is completle showroom stock with no after market air breathers or pipes. It is back in the dealers shop at this time for the second time right now for this problem. The dealer keeps telling me that there is nothing they can do about it as the timing is preset and cant be adjusted,and that this is characteristic of the C90T. I cant belive that Suzuki built this bike to back fire but thats what the dealer is telling me. I was just wondering if anyone has had this problem and if you solved it how did you solve it. At this point im very un happy as i spent $12000.oo plus on this bike and it back fires and all im being told is thats just the way it is and I'll just have to live with it.

[PENJO]

Originally Posted by Dan Janousek

I purchased a brand new C90T April 26, 2006. It back fires when I let off the throttle. I have 540 miles on it. It is completle showroom stock with no after market air breathers or pipes. It is back in the dealers shop at this time for the second time right now for this problem. The dealer keeps telling me that there is nothing they can do about it as the timing is preset and cant be adjusted,and that this is characteristic of the C90T. I cant belive that Suzuki built this bike to back fire but thats what the dealer is telling me. I was just wondering if anyone has had this problem and if you solved it how did you solve it. At this point im very un happy as i spent $12000.oo plus on this bike and it back fires and all im being told is thats just the way it is and I'll just have to live with it.

have you contacted Suzuki directly? have you check with another dealership? I am not the most experienced person about it. I have a C90T and before and after buying it i have been here snooping around to learn more and more, never read or heard about this back firing. The only time I have heard/seen back firing is with aftermarket pipes in C50s and Volusia among my friends. I personally would not settle for such an answer from the dealership, especially if I bought it from them. This is when my dark side comes out.

if interested and not already familiar with it, check this forum http://forums.delphiforums.com/n/mai...FRLCMC%2Fstart

The above is about LC1500/C90 lots of good info. Is this problem something that will go away or get worst? i just got my 600 check up done and so far have never experience anything like this.
Good luck to you. Hoping you can resolve it without loosing. Take care.

[intimid8er]

Dan....these things are set to be "lean" from the factory. A backfire on decel is indicative of a lean condition, but this seems too lean. Although, I have heard of some stock M/C 50's coming from the dealers in this condition, more often than not, it's not a factory problem rather it's the dealer's malfeasance.

Try checking things one at a time, and they are real easy. If you are not mechanically inclined, it's easy enough to do, so you can reduce your dependence on the dealer.

First place I would start is look at where the exhaust bolts to the engine. Do they appear aligned properly? If you have the right Allen Wrench (I don't know if they use Allen bolts on the C90's exhaust.), or if not an Allen, the right size socket, test the tightness of the head flange. If it's REAL loosey-goosey, tighten it up and take it for a ride. Check all of them if you are not sure, tighten them a bit. They only need 12-13 lbs of torque (which isn't much) you could either borrow a torque wrench or buy one.

If that doesn't solve it. It may be an improperly seated exhaust gasket, or improperly seated exhaust flange. Again fixed by the same method as above. Usually, if that is the problem though tightening them up should make it go away. If it doesn't......check back with us.......

[intimid8er]

Caveat.......

Before you do the above...I forgot to mention.....simply fire the bike up and put your hand near the flanges....and check for leaks. If they are leaking, good chance that is your culprit.

[PENJO]

Intimid8er,
Thanks as well from my part. Something new for me to know in case of ever the matter with mine. However, wouldn't this be something easy for the dealer to recognize and address? Just like you explain it, it seems like a no brainer.
Just on the little we know based on his post, i tend to be doubtful of the dealer's attention

[intimid8er]

Originally Posted by PENJO

However, wouldn't this be something easy for the dealer to recognize and address?

Crazier things have happened dude!

My bike was delivered with 46 or so lbs of pressure in the tires. This caused a severe wobble over 52 mph. They all told me I was crazy, there was nothing wrong with the bike. Air out...problem went away.

Dealers do make mistakes.

[Sgt Mike]

Dan, it sounds like there is an exhaust leak at the header gasket/flange area, and it doesn't take much of a leak to cause backfiring on closed throttle decelleration. If it's still in warranty insist that your dealer checks the header gaskets, not just the bolt torque. Let us know how you make out.

[PENJO]

Originally Posted by intimid8er

Crazier things have happened dude!

My bike was delivered with 46 or so lbs of pressure in the tires. This caused a severe wobble over 52 mph. They all told me I was crazy, there was nothing wrong with the bike. Air out...problem went away.

Dealers do make mistakes.

Hey bud you're right!

The bothersome thing is the response he got from the dealer about this being characteristic of the C90 and nothing they could do. Hummm. It sounds a bit incompetent or poor in customer service.

Well, the one great thing is that in the end here is you guys with the tons of experience and always willing to help, ALWAYS THANKS!

[moccasin]

Blame it on the EPA. Years ago, Suzuki figured out how to beat the EPA regualtions for importing their bikes into the US...They invented the PAIR VALVE! That's the ugly little critter that lives in your fake air filter on the right side of the engine.

First, check that all your header pipe nuts are snug, and if they are, then open that pair valve cover, slip the two rubber tubing connectors off the bottom of the pair valve and plug them with a round head screw.

The pair system on these bikes is an artifically induced exhaust leak, designed to flood the exhaust fumes with enough fresh air to fool the EPA inspectors. Problem is, it don't work, and the funny part is, they don't even test privately owned bikes for emmissions here (they only make requirements for manufacture)

Here's some more help for you:
http://www.moccsplace.com/images/pair/c90/c90.htm

[intimid8er]

Originally Posted by moccasin

Blame it on the EPA. Years ago, Suzuki figured out how to beat the EPA regualtions for importing their bikes into the US...They invented the PAIR VALVE! That's the ugly little critter that lives in your fake air filter on the right side of the engine.

First, check that all your header pipe nuts are snug, and if they are, then open that pair valve cover, slip the two rubber tubing connectors off the bottom of the pair valve and plug them with a round head screw.

The pair system on these bikes is an artifically induced exhaust leak, designed to flood the exhaust fumes with enough fresh air to fool the EPA inspectors. Problem is, it don't work, and the funny part is, they don't even test privately owned bikes for emmissions here (they only make requirements for manufacture)

Here's some more help for you:
http://www.moccsplace.com/images/pair/c90/c90.htm

Ahhh damnit Mike!!! Ya stole my thunder!! If the exhaust wasn't the deal, I was gonna send him your way for the PAIR deal!! Didn't want to bombard him with too much at first!! LOL

[mikenredding]

Do you know where I can buy the pair valve kit? So I can remove it totally. It does it on my bike to, like there is a hessitation when you 1st give it gas and sometimes it sounds like a small cough. I only have 300 miles now on my 2006 c90t.

[intimid8er]

Originally Posted by mikenredding

Do you know where I can buy the pair valve kit? So I can remove it totally. It does it on my bike to, like there is a hessitation when you 1st give it gas and sometimes it sounds like a small cough. I only have 300 miles now on my 2006 c90t.

Go to post #9 above you Mike. Click on Mocc's link there.

[mikenredding]

thanks

[Dan Janousek]

Thanks for the information, I do belive that the pair valve is my problem, and obviously the dealer wont do anything about my problem if the pair valve is causing the problem and im sure it is. I ordered the kit and will let you know how it works.
Thanks
Dan Janousek

[stp1971]

One other thing. You don't have listed where you live and at what elevation you live at. Higher elevations can drastically change the parameters of the air/fuel mixture. If the bike is already runing lean and you live in a higher elevation then that could be making the problem worse.

If it is running too lean check the pipes at and near where they bolt up for discoloration. Discolored pipes are a sign of a lean condition. Basically the bike runs hotter.

The bike has a computer on board that can be re-mapped if I am correct and it is quite possible that the mapping is screwed.

But I am with Mike,, the PAIR valve is probably your culprit. By the way,, I still need to order that kit for mine,,, lazy I guess. One of these days Mike I am shooting you an order,,, I promise!!!

[moccasin]

Originally Posted by mikenredding

like there is a hessitation when you 1st give it gas and sometimes it sounds like a small cough.

This is NOT a pair valve issue. If your bike is totally stock, this is an intake or fuel injection issue and should be looked at by a competent dealer that believes bikes shouldn't act that way.

The pair valve does not effect performance in any way. The annoying popping and gurgling noises that it creates occurs during DECELLERATION. If you have issues with ACCELLERATION, then you may have an air breather loose, or a possibly your FI system needs to be reprogrammed.

[stp1971]

Well I had to do the LC shuffle this morning. AAARRRGGGGHHHH!!!!!

[intimid8er]

Originally Posted by Dan Janousek

Thanks for the information, I do belive that the pair valve is my problem, and obviously the dealer wont do anything about my problem if the pair valve is causing the problem and im sure it is. I ordered the kit and will let you know how it works.
Thanks
Dan Janousek

Dan...What is your experience with bikes?

[Dan Janousek]

Thank you i instaled the pair valve removal kit and it totaly solved my problem, I would recomend that if you have a Suzuki C90T to do this. It doesnt increase the performance but totaly eliminated my back fire and poping problem on deceleration and made the engine run alot smother.

[Rog]

Mine SOMETIMES backfires if I don't give it enough throttle when taking off from a dead stop. It also seems that when I use mid-grade gas (Name brand gasoline) it does it less frequently. Does yours backfire only when taking off?

Rog