Vance and Hines Cruzers popping on decel carbed vl800

As the title says.
Things ive done:

Disabled pair valve (blocked the 2 bottom pipes)
Changed exhaust gaskets
Disabled pair valve further by blocking the 3rd pipe (the top one of the 3 on the valve) and removed the 2 into 1 pipe peice, and plugged the fuel pipe directly onto the tank

The very last thing i can think of is to tighten up the exhaust bolts. I used long allen keys like these:

http://www.toolstop.co.uk/components...99e59ca639.jpg

And did them up finger tight using the short end of the key (not the long which would tighten them up more).
I cant find any torque settings and its threading into aluminium so i dont want to strip the thread. Maybe there is a way i can check for exhaust leaks? I can feel air puffing near the front exhaust manifold but it kind of feels more like its coming from behind the air box on the right hand side of the 'football' (side closest to the front pipe)

I shouldnt need to rejet should i? Ive not heard of anyone else rejetting with a stock intake. I live more or less at sea level.
Thanks

If you have 'air puffing' its to lose, the torque setting of the bolts is 16lb. I just did mine up by only feel with the same tool as you and to be honest I very much doubt you could strip those bolts by doing them up by hand with an Allen key.

Im trying to use a torque wrench but there isnt enough clearance on the left hand bolt to do it up to spec ( or any room on the other pipe). I have the wrench set to 14Nm and even though its quite tight when turning, its still not reaching 14nm. Im assuming its crushing the gasket. Here are some pics

Might be worth just popping out and getting some sealant, other than that sorry I dont know if everything including the threads and bolt holes are clean

thnx anyway

I'd imagine if someone tightened them enough to bend that flange, the threads would strip.
They're v&h cruzers not stock. If that is the cause I suppose I could try and reshape them but they are very strong

That bottom picture shows a distorted header clamp.

I'd say you've not tightened them up enough if you've only done it with the short end? I did mine finger tight like you then used the long end for more leverage to fully tighten, The flanges on my pipes are straight but the ones on the straight shots I have are slightly curved like yours (probably from being over tightened), If you've put new gaskets in they'll compress quite a bit too, so could be worth nipping them up a little more, I'd only use an allen key though and not the socket set.

I've since tightened them and they still pop.
Urgh so another £400 for a new set of pipes then.

I've had my Cruzers off and on a couple of times without changing the gaskets, and have no leaks at all.

Are you sure you dont have a leak somewhere on the pipes to the PAIR valve ?

As you can see my Cruzers flange is also a bit distorted, but no leaks.

I would look at the gaskets again, and maybe use a bit of exhaust sealer.

It's too early to give up and buy new exhausts  :disagree: 

I can feel air puffing in that location. Yours are nowhere near as bad as mine. I don't think they are removable either. Could try and figure out a way to bend them back but that would weaken them.
Could check the hoses to the pair valve too but don't know how to get to them

Try using a barbeque lighter to pinpoint the leak.

Somewhere on the left near the airbox.
Took the pipe off and unfortunately the flanges aren't removeable.

I used these gaskets

http://www.ebay.co.uk/itm/like/221320828359?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&device=t&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=108&ff19=0

Is it normal to feel a little air puffing in that area? I cant tell if its the exhaust or the airbox

Have just been looking at your photos and the flange is well bent, looking at the clearance around the head it looks like it would be no problem to fit studs with nuts instead of of Allen bolts, this would be stronger and less liable to damage the threads in the head when tightening them up, also you could probably fit another flange that has been cut in half as this would spread the load and help prevent or minimise distortion, will have a look at Mr Intruders exhaust and get back to you, regards Doc Cox.

Thank you

EazyDuz wrote:

Is it normal to feel a little air puffing in that area? I cant tell if its the exhaust or the airbox

No it's not normal to feel any air puffing in that area, the straight shots I had fitted to mine had bent flanges and didn't leak gasses at the headers neither does the pro pipe, I'm not sure you would get any pulses of air coming out of the air filter either? unless it back fired through the box, I'll suggest loosening all the bolts front and rear, then applying some sealant around the headers before doing the flanges up finger tight as square as visibly possible, then nip them up before tightening the can hangers up at the rear.

  

Maybe the gaskets are at fault and I should have got OEM ones?

I am wondering if a badly fitting gasket could be so bad as for you to feel the blow, seems the fit is just not anywhere tight enough to me

To update:
I wasnt sure if the blowing was coming from the pipe or somewhere behind the airbox. So i took the airbox off and made sure all pipes were fully secured, i also loosened off the pipe and repositioned the gasket and put it back on.

One of those things got rid of the air blowing in that area as i cant feel it now.
Anyway, i still have popping, though not as bad. It just does it when coasting in gear. BUT, if i add a tiny bit of choke, or even 5% throttle, or increase the idle speed a bit the popping all but goes away. Instead it just kind of gurgles which i think is a characteristic of the V&H Cruzer exhaust. If i drop the idle low it pops like mad even in neutral.

So my question is, could there still be an exhaust leak which is causing it? And all the things which stop it popping are just compensating for the leak? A guy i know could straighten the flanges for me for a better fit if it would help.

For my three pennorth why not take the pipes off the heads again & use some silicon sealer, let it dry overnight & that should sort the exhaust 'popping' out no problem.
If it still pops then I'd suspect the airbox area or something as it should not do it after the seal is siliconed up.
Why may I ask do you need to alter the choke or throttlle, is it not set up correctly? eg idle set too low???

peardrop3 wrote:

For my three pennorth why not take the pipes off the heads again & use some silicon sealer, let it dry overnight & that should sort the exhaust 'popping' out no problem.
If it still pops then I'd suspect the airbox area or something as it should not do it after the seal is siliconed up.
Why may I ask do you need to alter the choke or throttlle, is it not set up correctly? eg idle set too low???

Im going to get the flanges flattened. Two new gaskets, new studs, bolts and sealer then. If that doesnt work i give up!

Is there a particular brand/type of sealer i need? And where do i apply it, on the gasket itself or just the flat metal surface of the pipe where it meets the head?

Any bathroom sealer will do as it goes hard when it's got hot believe me! If it works on my 500 Velocette it will work on your VL800.

Im confused Peter what do you mean by bathroom sealer, corking or Silicon or grout? that sounds bloody strange. 
I think I would just buy something meant for the job, won't be very expensive either way

Grout every time! Don't be using the cheap stuff though!      Silicone really!   on a side note though? Silicone sealant is acidic and promotes rust and corrosion! I'm not sure about the automotive stuff though? gasket sealant and the likes so could be worth reading up on  

Maybe he means toothpaste, I grouted a few tiles around my fire place with some of that years ago when I had nothing else and it went rock hard  

Seeing as Simbo has answered i'll say nothing else on the matter except this. I used ordinary bathroom/window silicon sealer on the Velo exhaust & it lasted 5 years ok.

I have known people use high temperature copper silicones but normal bathroom sealant I have never known used. Even Loctite's copper based 5930 max's out at 350 Celsius. Gotta experiment a little with that when I get a minute.

So where do I apply it?

peardrop3 wrote:

Any bathroom sealer will do as it goes hard when it's got hot believe me! If it works on my 500 Velocette it will work on your VL800.

Silicone bathroom sealer is a very useful product which can be used for many types of sealing, filling gaps etc, it could also be used how peardrop3 has suggested.

On the gasket?

EazyDuz wrote:

On the gasket?

Yeah  

Glad you got it sorted    nice sound on those cruzers!

Good on ya, simple fix then. just glad your sorted  

Pleased it was so easily fixed, the photo said it all for me. Well pleased for you, simple shite can at time cause a big headache.   

Sorry Peter   

I have an apology to make with regards to a jest remark about using standard silicon sealant on the exhaust for sealing the gap.
I have now researched the comment with regards to using silicon for this purpose a bit more & also spoken with Doc Cox. It would seem that this is not as Arthur Daley as I at first thought.
So as I am never one to avoid eating humble pie when I need to, here goes....................   

You learn something new every day  :shock:

I obviously knew you could use silicone bathroom sealer for exhaust sealant   Like fuck I did!   

On a more serious note though? Don't use acetic cure silicone on metal as it causes rust and corrosion! just check with the silicone manufacturer that it's neutral (none corrosive) cure silicone.

Dave no apology required mate as I was amazed when first introduced to the fact by a friend who has built his own V-twin Velocette sidecar outfit 'The Vulcan'.
He did me a little job on a previous Velo I had & when I picked it up he said 'wait till tomorrow when the silicon on the exhaust is set before starting it up', puzzled look & explanation asked for & he told me it was something they used down the pit to seal the exhaust on the underground diggers etc...
CC & Sim, yes you learn something everyday guys!

Funny that some are getting rid of the popping on overrun while I wouldn't mind some   

Just when I thought it was gone it seems to be returning. Noticed it pretty soon after I filled up with tesco fuel but surely that wouldn't cause the problem? Its still not very loud but a more regular put put put on engine braking most noticeable in 4th it seems.

The gear your in will make absolutely no difference to the popping to some extent, only the the engine RPM at the time of the engine brake will encourage or discourage it. It can be noticed more in higher gears simply due to the speed you are doing keeping the momentum going.
How exactly did you end up getting the initial desire result? Was it by flattening the flange a bit, fitting gasket and then using a sealant of some description to give a perfect fit? Flattening the flange, fitting gasket & directly fitting it without any sealant. or other
More detail needed to stop the guess work.

Flattened flange and new gaskets, no sealant. I have been running redEx through it too if that would make a difference?
The gaskets aren't OEM though, they're from 'gasketsman' on eBay. Still, wouldn't have thought they'd lose a seal if untouched

It has got worse still.
Guess I'll need to fork out £20 for the OEM gaskets and try again. All aftermarket ones ivr tried are very poor quality. What a bore! It makes the bike run way too hot.

Have you tried silicone sealer?

simbo wrote:

Have you tried silicone sealer?

Not yet, would it even work on already crushed gaskets?
Plus I've heard its a nightmare to clean off and reapply if I ever need to take the pipes off again. Also I'm not sure how much or where exactly to use it.