New bike (2007) Header question, and shock question

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vmaxer06

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In 2022 I sold my 2006 Vmax, with plans to buy an older model, just a runner, for a couple thousand less. After looking around all this summer, I decided I really did like the 06-07 bike color schemes, so on Monday I bought a 2007 in nice condition. However it came with what appears to be Cobra slashcuts, and I have read/known all the disadvantages of these pipes, as far as robbing horsepower, etc. So my plan was to bring it home, and take it to a local Vmax shop and have them put a 4-2 exhaust with jetting on it. I got home at midnight Monday night from driving 3 states away to pick it up, so I didnt have a real chance to ride it until last night after work. ITS FAST!! I was expecting a dog with those slash cuts but I am 100% sure its faster than my 2006. I know its been 1.5years since I sold my 06, but I kinda have an idea what fast is, as I have a 2010 Gen 2 with 187 rwhp, a couple 900 Eliminators that run perfect and are very quick, etc. I started off with bikes at 18, and rode through college, then got married and had 4 kids and didnt have a bike again until 2020 (age 57) when bikes were really cheap during Covid, and I bought several and started riding again. I take good care of my bikes and dont beat on them, but I had often taken my 06 on rolling start runs to 85 mph close to the redline.

Anyway after all this rambling, as we were waiting for a notary to show at the bank, it just kinda hit me when looking at the bike that the chrome headers on this bike seemed to be larger than what I remembered on my 2006, and I might just be forgetting also. One reason they caught my eye was that they had some discoloring in the chrome, and I didnt remember that on my 06. The person I purchased it from was the 2cd owner, and the first owner had the Yamaha dealership put the exhaust on and jet the carbs accordingly, so he didnt know the whole specs for what was done. So last night I took my calipers and measured the header pipes and they measured around 1.84 OD. I was wondering if someone that has stock headers on their bike, could measure the OD for me? I am curious to see if the original owner put headers on the bike, and that might be why these slashcuts seem to perform, as I read on this site that one of the reasons the Cobras dont perform is that they use the smaller factory header pipes. In riding the bike it seems to be quicker in the 3-5K range before hitting the Vboost, and because it seems to ramp up quicker, the vboost might not feel as defined, although the boost is there and fast, and that is what I read on this site that the cobras make the vboost a little mushy. Another thing that I did notice was that it seemed that the oil light would flash on quicker than my 06, as I got close to the redline, almost like I was getting there quicker. I know I will probably have to get it dyno'd to make a decision on a different exhaust. If it dyno's 100 hp, its gone. If it dyno's 113+ hp, I will keep it as is, as I dont want a Stage 7, just a little more than stock, like a Stage 1. In looking at the header pipe, it looks like it necks down before going into the slash cuts. The slash cuts have 1.25" OD exhaust pipe exits inside the chrome outer cans.

Another question is on the rear shocks. I noticed that the factory 2007's have a chrome top cap, whereas the one I bought has a black top cap. I am wondering if the previous owner possibly lowered the rear, as it seems to sit lower than I remember my 06 did. I always wanted to lower my 06, but never did, and I really like how this one sits. It does have a Corbin seat, and I have never sat on a Corbin on a Vmax, so dont know if that seat changes the height slightly or not. I measured the shocks at approx 13.25" mounting hole to mtg hole.

The bike came with newer Michelin tires, and it might be my imagination, but it seems to handle better in the corners than my 06 with Metzeler tires. Any comments on Michelin versus Metzeler tires for handling? They are not radials.

I was happy not to find "the Vmax wobble" in my riding last night. The guy I bought it from said it didnt wobble for him until he hit 130 mph, so since I will never ride it up to 130, I should be good 🙂.


I have attached a couple pics for observation. I have found the guys on this Vmax forum have a wealth of Vmax knowledge that I dont have. I rarely post, but read and enjoy the forum posts frequently.
 

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What I have gathered in the past is that if the pipes are discoloring then they are getting too hot. This may be a sign that the bike it running too lean. It would be interesting to see what the spark plugs look like to support this, if they have some miles on them.
 
The front OEM pipes are double-walled, so they don't typically discolor significantly. Aftermarket front downpipes are usually larger dia & single-walled.
 
Ok, thanks, I didn't realize that the factory headers would be double walled. If I can get a measurement of the stock header OD I will know for sure.
 
They are the stock headers as noted by the decorative clamp bracketry/covers. It also has Cobra slip-ons which are good for about a 10% power loss. Either install any other slip-on or the stock mufflers to regain that 10%. If you want another 10% above stock then you need a full aftermarket header.

Exhaust Comparison 2.jpg

Exhaust Compare 1.jpg
 
Thanks for the input. I will proceed with my original plan to take it to my Vmax shop (formally UFO) here in Ohio.
 
Thanks for the input. I will proceed with my original plan to take it to my Vmax shop (formally UFO) here in Ohio.
I heard the same thing about the cobra slasher pipes not being that great. My 02 came with a set of them as extra parts. Anyway i put them on and with the already installed stage 7, I think it's faster too. And it sounds like a race motor. Smells a little rich, I can live with that. Not sure if I'm going to put the factory pipes back on.
 
Cobras are awful. There is no such thing as tuning them. They are complete garbage and should never be used on a running Vmax.

In a museum, not running ever again, sure. They look fantastic.
 
UFO Quadzilla.
Evil
Wicked
Mean
Nasty

Wear the best ear protection you can find.

VMax friends tell their Vmax friends, "just say no to Stage 1 kits."

OEM shocks are 13" O.C. Going any more than 1.5" shorter is going to cause you even-worse grounding-out issues. I would not recommend more than 1" shorter, i.e., from 13" to 12". The sidestand will have the bike more upright and the centerstand may be impossible to deploy if you are smaller. There are aftermarket sidestands with adjustable height. Running shorter height 17" or 18" wheels w/lower aspect ratio tires will contribute to the problem of sidestand. & centerstand height and use.

Corbin seats (I use one) are lower but wider so if you're short they may be difficult for you to be flat-footed at a stop.
 
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I heard the same thing about the cobra slasher pipes not being that great. My 02 came with a set of them as extra parts. Anyway i put them on and with the already installed stage 7, I think it's faster too. And it sounds like a race motor. Smells a little rich, I can live with that. Not sure if I'm going to put the factory pipes back on.
Well I guess I can't live with it running to rich. I think I fouled a plug, not positive, but think so. I'm wondering if with the stage 7 installed, a different plug then the NgK DPR8EA-9 or equivalent would work better, a hotter one. I was stuck in traffic a little more than I normally am. I hoping it's not in the carbs, maybe a 3k since st.7 install.
Probably yard those plugs tomorrow, maybe just need a clean, but wondering what you guys have experienced. Thanks
 
Pal, you are absolutely desperate to cure the incurable. From the other thread:

Pal, if you are still running the Cobra pipes, there is nothing - REPEAT: NOTHING - you can do to sort that out. It will run rich, foul plugs and perform like shit forever.

The only possible fix is to get rid of those shit pipes.

Constantly looking for help with Cobra pipes is an exercise in futility. There is NO HOPE for them. They ruin your bike in every way except looks.

You can not tune a pipe that was never tuned to begin with. Cobra pipes are an aesthetic and that is it.

Analogy: you bought a square rim. It doesn't ride smoothly, so you're posting all over the forum about how to get a smooth ride out of a square rim.

There is only one answer: get rid of it. Buy a round one. @CaptainKyle and @one2dmax in all likelihood have several good, performance options used that you can get a good deal on.
 
UFO Quadzilla.
Evil
Wicked
Mean
Nasty

Wear the best ear protection you can find.

VMax friends tell their Vmax friends, "just say no to Stage 1 kits."

OEM shocks are 13" O.C. Going any more than 1.5" shorter is going to cause you even-worse grounding-out issues. I would not recommend more than 1" shorter, i.e., from 13" to 12". The sidestand will have the bike more upright and the centerstand may be impossible to deploy if you are smaller. There are aftermarket sidestands with adjustable height. Running shorter height 17" or 18" wheels w/lower aspect ratio tires will contribute to the problem of sidestand. & centerstand height and use.

Corbin seats (I use one) are lower but wider so if you're short they may be difficult for you to be flat-footed at a stop.
Thanks a lot for this information says this Newbie !
 
UFO Quadzilla.
Evil
Wicked
Mean
Nasty

Wear the best ear protection you can find.

Darren Kohls says:
Thanks a lot for this information says this Newbie !

https://starriderperformance.com/vmax-1985-2007/
Mike took over after Jon Cornell died. It was UFO under Jon, and Mike Lees now provides parts and services under Star Rider Performance.

Here's the Quadzilla. Note that while this has a superficial resemblance to the Cobra four into four, it is a complete header/mid-pipe/exhaust canisters system where the headers are enlarged.

https://starriderperformance.com/st...-quadzilla-mufflers-ceramic-coated-85-07-all/

I have the Dragstar 4/1 but I replaced the canister with one from a literbike to quiet the Dragstar end, which is nearly an open header. Some info on that mod: https://www.vmaxforum.net/threads/ufo-4-1-alternative-canister.29889/

My big canister UFO 4/1, which is able to be ridden without risking ear damage:
1715618356929.png

The Quadzilla from Star Rider Performance, formerly UFO:

1715617311587.png
The Dragstar 4/1 in all it's ear-splitting glory. Even the H-D aftermarket exhaust guys will cover their ears as a Dragstar-equipped bike hits VBoost rolling-by. "Whoa! Too-loud!"
1715617757777.png
The Dragstar, not to be ridden without ear protection!

A thread about the founder of UFO, Jon Cornell. Start at the beginning. It's good to know the history behind the development of the aftermarket support for the VMax.
https://www.vmaxforum.net/threads/jon-cornell-has-died.30139/#post-324211
 
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