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conman
10-29-2007, 03:19 PM
Yesterday I changed the plugs to the Iridium ones that were recommended and have noticed two things: first off the bike starts much easier without using the cold start button.
secondly, after I started it up and let it warm up it sounded like it was running rough on a cylinder. I put my hand behind the exhaust (GPR'S) and the left one(rear cylinder) is nowhere near as smooth as the right side (front cylinder) it almost sounds like a timing issue.....
any ideas, comments would be appreciated..

duc slayer
10-29-2007, 03:22 PM
how new is the bike and who set it up initially, basically I'm just trying to see if this was there 1st setup job or do they now what's what

orangerider2
10-29-2007, 03:25 PM
Make sure that the plug caps snapped on tight. It can run on one cylinder.:cigar:

conman
10-29-2007, 03:32 PM
Make sure that the plug caps snapped on tight. It can run on one cylinder.:cigar:

yeah, I will check that when I get home, only thing is though, I rode it afterward and it didnt seem down on power at all.
have you ever heard what sounds like the timing chain slapping against the tensioner at startup?
only does it initially until the oil pressure gets up it seems and not every time. usually only when I first crank it in the morning.

conman
10-29-2007, 03:34 PM
how new is the bike and who set it up initially, basically I'm just trying to see if this was there 1st setup job or do they now what's what

the bike has 2400+ miles on it now., it didnt sound like that until I changed the plugs though.

orangerider2
10-29-2007, 03:39 PM
If it`s running only on one cylinder, it can make that sound.:cigar:

conman
10-29-2007, 03:51 PM
If it`s running only on one cylinder, it can make that sound.:cigar:

it's a sxv 450 and still runs over a hundred mph. it seems hard to believe that it's only on one cylinder wouldnt you agree?
I will still pull the rear plug wire and see if it changes.
what about the valves? if they were out of spec couldnt they cause the popping and irratic behavior?

orangerider2
10-29-2007, 05:51 PM
Start with the easy stuff first.:cigar:

soyrico
10-29-2007, 06:14 PM
yeah, I will check that when I get home, only thing is though, I rode it afterward and it didnt seem down on power at all.
have you ever heard what sounds like the timing chain slapping against the tensioner at startup?
only does it initially until the oil pressure gets up it seems and not every time. usually only when I first crank it in the morning.

My bike made that same exact sound when got it home brand new from the dealer. in fact it did it twice, once when it had 2 miles on the speedo and a second time when it had 20 plus miles on the speedo. The strange thing is that it made that sound while I was riding at high revs. The good thing is that it hasn't made that noise since then and I have 200 + miles now.

My mechanic told me that these bikes will make that sound when the bike is just above the stalling RPM. I've also heard it from seasoned Aprilians owners as well. I'm still new to this forum myself and still learning.

orangerider2
10-29-2007, 06:21 PM
That sound at low idle, is from the de-compressors.:cigar:

RXV_Poor
10-29-2007, 06:49 PM
I've also heard it from seasoned Aprilians owners as well.

Seasoned, I never thought I'd be called seasoned maybe :confused::bangwall: :blah::crowbar::crybaby::nutts::bitchslap:ripass: but not seasoned.

waxxer
10-29-2007, 07:06 PM
Seasoned, I never thought I'd be called seasoned maybe :confused::bangwall: :blah::crowbar::crybaby::nutts::bitchslap:ripass: but not seasoned.

Garlic, olive oil, cumin, corriander, curry--now that is seasoned.

MickyC51
10-29-2007, 09:41 PM
Garlic, olive oil, cumin, corriander, curry--now that is seasoned.

How'd I get involved

Micky "Curry"

rednotch91
10-29-2007, 09:43 PM
Mine makes a similar sound when it's idling too low, like down around 1600 or so.....if that helps any

SLORider
10-29-2007, 10:03 PM
Could it be a weaker spark at low rpms doesn't fire, but at high rpm it jumps the gap in the loose cap or wire? Check the caps. I understand the rubber caps can break the resistor inside when tugged on. Feel if the bad cylinder cap feels broken inside. Better yet, replace them. They are like $2.50 USD.

Like orange says, start simple. Also, remember, it's probably what you touched that messed it up. Too coincidental otherwise.

conman
10-30-2007, 12:28 AM
Could it be a weaker spark at low rpms doesn't fire, but at high rpm it jumps the gap in the loose cap or wire? Check the caps. I understand the rubber caps can break the resistor inside when tugged on. Feel if the bad cylinder cap feels broken inside. Better yet, replace them. They are like $2.50 USD.

Like orange says, start simple. Also, remember, it's probably what you touched that messed it up. Too coincidental otherwise.

I agree, I tried taking off the cap on the rear cylinder and then the bike wouldnt even start. I guess it could be a bad cap or cable and cap. I am going to replace them tomorrow and see if that helps.
Thanks for the responses.,

conman
10-30-2007, 06:29 PM
well I changed the plug caps with new NGK Hard plastic ones and now it seems maybe even a little worse than before. :pissed:
I guess I could get some new SP wires as well and just change everything.
like I said before, the right side(dont laugh) is a steady - pop pop pop pop pop pop and lots of pressure out the back on my hand. the left side (rear cylinder) is kinda like - dededededePOPdedededePOPdedededededePOPdedede...et c etc.........
and very little pressure except when it "POPS"
I know this sounds juvenile and uneducated about mechanics but that is really not the case. I have been riding and racing MX since I was 5 years old and this is just the first time I have had a V-twin anything and with all the experience on this forum I didnt think there was anyone better to ask.
if the valves were out of spec, could that be causing the same kind of sounds and feel or would it seem more likely that the rings could be going?

orangerider2
10-30-2007, 06:36 PM
Before you screwed in the new caps, did you trim a little off of the plug wires? Also check the wires going to the coil, make sure that the connections are tight.:cigar:

Alice Racing
10-30-2007, 06:44 PM
Idle too low, throttle bodies out of balance ?

conman
10-30-2007, 06:47 PM
Before you screwed in the new caps, did you trim a little off of the plug wires? Also check the wires going to the coil, make sure that the connections are tight.:cigar:

yes, about 1/8" and I will go check the coil after dinner. thanks..

conman
10-30-2007, 06:49 PM
Idle too low, throttle bodies out of balance ?

it idles about 1700, and I have NO idea about the throttle bodies being out of sync.....
is there a simple way to check that or am I going to need them pressure tested?? thanks...

orangerider2
10-30-2007, 07:13 PM
It should between 1800-2100RPM`s.:cigar:

conman
10-30-2007, 07:26 PM
It should between 1800-2100RPM`s.:cigar:

well it is a little low then,
you know they say a picture is worth a 1,000 words..........check this out please: http://s170.photobucket.com/albums/u263/v2comp/?action=view&current=sxvcylinder.flv
or this if that one doesnt work:http://i170.photobucket.com/albums/u263/v2comp/th_sxvcylinder.jpg (http://s170.photobucket.com/albums/u263/v2comp/?action=view&current=sxvcylinder.flv)
you have to excuse the girl at the end - lol

TGK
10-30-2007, 07:27 PM
it idles about 1700, and I have NO idea about the throttle bodies being out of sync.....
is there a simple way to check that or am I going to need them pressure tested?? thanks...

You'll need a mercury carb stick (basically tubes with mercury on a scale) or they make digital synchronizers. You must hook it up to the throttlebodies at a vaccum port. Idle the bike and adjust the butterflies to get the vacuum equal on both cylinders. Pretty simple if you got the tool. I found it necessary to make my RXV550 managable at low rpms. And could be the cause of your symptom. One cylinder lagging behind at idle.

Alice Racing
10-31-2007, 04:35 AM
You'll need a mercury carb stick (basically tubes with mercury on a scale) or they make digital synchronizers. You must hook it up to the throttlebodies at a vaccum port. Idle the bike and adjust the butterflies to get the vacuum equal on both cylinders. Pretty simple if you got the tool. I found it necessary to make my RXV550 managable at low rpms. And could be the cause of your symptom. One cylinder lagging behind at idle.

Before you get that involved, get the dealer to ensure the closed throttle setting is correct. The linkage balance screw MUST be slackened to do this properly, as the rear throttle can hold the front off its stop, and the TPS is on the front one.
I disagree with setting using Mercury guages..........both throttles should open together. You do not race at idle !

conman
10-31-2007, 07:40 AM
Before you get that involved, get the dealer to ensure the closed throttle setting is correct. The linkage balance screw MUST be slackened to do this properly, as the rear throttle can hold the front off its stop, and the TPS is on the front one.
I disagree with setting using Mercury guages..........both throttles should open together. You do not race at idle !

what if the dealer is 5.5 hours away? can I do that myself without any special tools?

Alice Racing
10-31-2007, 09:55 AM
No chance, you need the Axone.

conman
10-31-2007, 10:24 AM
No chance, you need the Axone.

Go#$%&^%&^%*&^(*&(^%&&*:bangwall:

TGK
10-31-2007, 10:38 AM
Before you get that involved, get the dealer to ensure the closed throttle setting is correct. The linkage balance screw MUST be slackened to do this properly, as the rear throttle can hold the front off its stop, and the TPS is on the front one.
I disagree with setting using Mercury guages..........both throttles should open together. You do not race at idle !

Oh but I must disagree Alice. If your riding a Hare Scramble with an RXV your racing at idle ALOT! And if you synchronize the throttlebodies with a vacuum gauge at idle they will be openning the same.

TGK
10-31-2007, 11:36 AM
Go#$%&^%&^%*&^(*&(^%&&*:bangwall:

Hey Conman don't get all uptight now. Orange has the right idea just turn up the idle and enjoy that awesome machine you are so fortunate to own.

MickyC51
10-31-2007, 11:48 AM
[QUOTE=conman;1617888]Yesterday I changed the plugs to the Iridium ones that were recommended

What irridium plugs weree reccomended?

Micky Curry

duc slayer
10-31-2007, 12:03 PM
cr8iex I believe, I would also have to assume that AF1 has them listed in their shop online section

conman
10-31-2007, 12:12 PM
cr8iex I believe, I would also have to assume that AF1 has them listed in their shop online section

that is correct sir!

Alice Racing
10-31-2007, 01:02 PM
Oh but I must disagree Alice. If your riding a Hare Scramble with an RXV your racing at idle ALOT! And if you synchronize the throttlebodies with a vacuum gauge at idle they will be openning the same.

No, doing it with guages will mean they do not open together.

TGK
10-31-2007, 01:35 PM
No, doing it with guages will mean they do not open together.

Okay maybe a very slight difference in cylinder head to piston clearance or valve timing from one cylinder to the other would be compensated by vaccum and butterfly position. But aren't we splitting a very fine hair here?

Alice Racing
10-31-2007, 04:20 PM
No because the maps are very different for each cylinder.

TGK
10-31-2007, 04:56 PM
No because the maps are very different for each cylinder.

Why is that?

Alice Racing
10-31-2007, 05:01 PM
Just the way they are mapped from the factory............v twins always have the rear cylinder richer, but these are very different.
They run nicer if the throttles open together, and many are set a long way out from new..........thats the point i am trying to make.

orangerider2
10-31-2007, 05:31 PM
conman says that the bike was fine until he changed plugs, so my thinking is that his problem is somewhere in the wires, or even a bad spark plug, i have had new plugs that were no good.:cigar:

conman
10-31-2007, 05:45 PM
conman says that the bike was fine until he changed plugs, so my thinking is that his problem is somewhere in the wires, or even a bad spark plug, i have had new plugs that were no good.:cigar:

well maybe I mispoke to a certain degree, I didnt notice it so dramatically until I changed the plugs, but that could also be because I was only trying to get the bike to start easier and therefore may not have been that aware until then. I really dont know.
well today I fixed the micro rear turn signals that had broken wires that the previous owner had put on it. they work now., lol

I replaced the plug wires today and installed a new twinair filter too.
I used a friends manometer and made a very minor adjustment but am still not satisfied that they are the same. I increased the idle speed to between 1900 and 2000 as well. it does sound better, but definently still not as smooth as the front cylinder.
next is the valves tomorrow, just to check to see if they are in spec.:bangwall:

orangerider2
10-31-2007, 05:53 PM
Is your exhaust gasket leaking at the rear cylinder?:cigar:

conman
10-31-2007, 05:56 PM
Is your exhaust gasket leaking at the rear cylinder?:cigar:

cant tell, if it's a visual check I will try tomorrow morning.

RXV_Poor
10-31-2007, 07:36 PM
cant tell, if it's a visual check I will try tomorrow morning.

I suggest buying the Yamaha gaskets and grinding them down. Also while your at it replace the bolts with studs.

It was suggested awhile ago to me and I'm glad I did it. No leaks and no stripped heads. :plus:

SLORider
10-31-2007, 08:27 PM
replace the bolts with studs.

It was suggested awhile ago to me and I'm glad I did it. No leaks and no stripped heads. :plus:

I remember that post. Stripped heads, eh? http://www.thumpertalk.com/forum/images/smilies/eek.gif

RXV_Poor
11-01-2007, 12:00 AM
I remember that post. Stripped heads, eh? http://www.thumpertalk.com/forum/images/smilies/eek.gif

No I haven't stripped the heads, yet but better safe than sorry for $2.00.

TGK
11-01-2007, 10:13 AM
Just the way they are mapped from the factory............v twins always have the rear cylinder richer, but these are very different.
They run nicer if the throttles open together, and many are set a long way out from new..........thats the point i am trying to make.

I so get your point. The butterflies were off by quite a bite when I got my bike. I adjusted them using my mercury gauge. Now the bike is so sweet. For me it's an awesome woods bike. It has so much low end grunt which I can manage do to the G2 throttle cam and synchronizing the TBs.

SLORider
11-01-2007, 12:32 PM
No I haven't stripped the heads, yet but better safe than sorry for $2.00.
What did you use for studs? Remember the dimensions and source?

RXV_Poor
11-01-2007, 02:44 PM
What did you use for studs? Remember the dimensions and source?

I took the bolt out and brought it in. M8 x 1.25 I think and I got them off the shelf at NAPA auto parts.

I also ground down some the weld inside the pipes to help flow.

dazmotronic
05-26-2009, 06:25 AM
Hi if that is the exhaust mounting studs at the head, i'm sure that are M6x1x30mm. I just cut down bolts and used hi strength loctite to install them, the TX125 Yamaha gaskets are the schnizzel, just a bit of work to get them ground down.
I have cut a second sey of flanges out of 3mm stainless and split them through the centre and welded then onto the original flanges, stops them bending at treat.

proslider
05-26-2009, 07:28 AM
This may be a dumb question, but did you try putting the used plugs back in to see if it made a difference?