Front Spark Plug
 

Hiya,

I've searched the forums to try to help, but some of the threads have been deleted, so I thought I'd try posting - apologies if it has already been covered...

I wanted to change the plugs today - the previous owner did all his own maintenance and according to the schedule shoudl have been replaced 2k ago, but I though I may as well...

Undid the front rad bolt, moved it forward to get access, got a socket onto the plug, and it was very stiff to undo - got it off in the end. Put the new one in, and tightened it up, definately wasn't cross threaded, but, it was staying the same tightness - couldnt get my torque wrench on, but didnt feel too tight. The rear was smooth, and nipped up nicely - but the front was different...

The old plug had quite a lot of crud around the thread - maybe I should have applied some wd40 to the new one???
It runs fine though - but I want to get it right - didnt tighten it too far as obviously didnt want to cross thread it.

What should I do? Leave it? Or take it out, clean it up and lube?

Cheers all.

Billy.

Re: Front Spark Plug
 

I use coppaslip on plug threads since watching my mate writhe the head off one in a ford OHV block...

If you do play with it be very careful, heads are expensive!

Re: Front Spark Plug
 

Good idea - got some coppaslip in the garage - knew it would come in useful!

Does / has anyone else had this problem? or am I just a numpty? Actually I know the answer to the second question...:(

Re: Front Spark Plug
 

The plug recess had some crap in it which you've likely just wound down the plug thread, pull the plug out a few turns and with an air line blow out the recess completely, then pull the plug out and check the thread carefully. If there's any damage chuck it away and fit a new one, grease is a good idea but won't counter any crap in the hole.

Re: Front Spark Plug
 

You could also try wash the crap out of the threads with WD or whatever, but the last time I tried this it resulted in one impressive backfire even after leaving it overnight to let the solvent evaporate... (not on an SV but was still an engine...)

Re: Front Spark Plug
 

Thanks Sid - havent got an airline, but I'll figure something out.

Just a question tho - how easy is it to strip the thread? When it happens, do you know about it? Is there a crack followed by it turning easier?

Sorry for the novice questions, just want to make sure I do it right.

Thanks.

Re: Front Spark Plug
 

If you strip it, it usually follows crossthreading, so it feels tight, then all of a sudden spins as the threads get munched out of the way...
Wind the plugs in by hand to make sure theyre going in properly thats how I've always done it, seems the safest bet.

Also possible to strip by using too much torque, but that takes more effort than the crossthreading...

Re: Front Spark Plug
 

Was thinking of doing that...maybe not now...lol - Worried about crap getting into the cylinder too.

Hope thats the reason for it not nipping up - thought Id really messed up my pride and joy!

Re: Front Spark Plug
 

Don't think Ive managed to cross thread - I was pretty careful at first, and didnt use the ratchet - just by hand.

The other thing is that the cap at the end of the spark plug lead - the one that fits into the cylinder head recess - doesnt seem as deep as the rear cylinder - I think water could easily get in - again pointing to the fact that the plug is prob not in enough - mind you, still runs ok...

Re: Front Spark Plug
 

Specifically in the case of a plug, which is steel, (harder), and the cylinder head which is aluminium alloy, (softer), the thread in the head goes first unsurprisingly, which is why it's so important to be careful, if there's ANY resistance to the plug turning by hand until seats, stop immediately and find out why
If the thread truly is stripped then it'll just turn uselessly and not tighten at all, but realistically you should never get to this point - if it's not turning easily you wouldn't continue. Yours doesn't stripped - yet. But there's clearly something amiss, if the thread has some damge now, you'll need to be sure that it's treated very carefully when removing the plugs in future. Very carefully remove it as I said above and make sure it goes in right.

Re: Front Spark Plug
 

don't talk to me about spark plugs. still attempting to find someone out there who supplys plug caps for the raptor

Re: Front Spark Plug
 

Well...I took the plug back out last night - and with WD40 and copaslip re-inserted it, took it out, cleaned the crud off - did this about 6 times, and finally got the plug in a lot further - the rubber cap now fits into the recess of the plug hole on the cylinder head much better now.

When I was tightening, you can hear the crunching as the threads get caught up in the crud - i was careful though and didnt tighten it up too much. Just wondering if anyone has used one of these for cleaning out the crud from the threads of the spark plug hole?

Spark Plug Thread Chaser 10 & 12mm
Code: Sealey VS524http://www.sealeytools.co.uk/uploads/small/VS524.jpg Spark Plug Thread Chaser 10 & 12mm

Specification

Model No:VS524
Plug Size:10 & 12mm
Price: £8.52

<< Back To

Or are they for re-tapping a threaded hole?

Am tempted to use vaseline on the rubber cap to try to stop anything else getting in there too...

Re: Front Spark Plug
 

Well, silicone grease is much better than vaseline and cheap enough from maplin.

A thread "chaser" is for finishing or cleaning threads, the only problem is I doubt it will fit down the hole, and if it will then a socket to get hold of it probably won't.

Try a small bottle brush or something like to clean the threads, that and **** it with WD, the backfiring doesnt do any harm (IMO) and has only ever happened to me once.

Re: Front Spark Plug
 

Cheers Chris - what about the crud going into the front cylinder - I was going to do that last night, but didnt want to do the valves any damage.

I'll get me hands on some silicone grease - in the meantime I've got silicone spray which will have to do...

Re: Front Spark Plug
 

Well that does concern me, but whats worse? accelerated wear of cylinders and valves (if at all) or an engine that doesnt run at all?

Re: Front Spark Plug
 

Yeah fair point - thought the engine runs fine - definately runs on both.

Mind you...backfires on no throttle at about 3k when decellerating...nice little pops!!!

Re: Front Spark Plug
 

Yeah mine does that since I put the Fuel can on it ... lurvely :D

Edit: when you screw the plug in does it actually seat or no?

Re: Front Spark Plug
 

not as much as my two do!!!!!! usually a bit of a damp start makes em do that or crap in the petrol. mine needed fuel yesterday and did it until I had a fill up. Having a couple of erhem..noisy exhausts never harmed anyone!!

Re: Front Spark Plug
 

Am pretty sure it doesnt - it goes in finger tight for maybe...4 turns or so, then need to use the ratched - but still really loose, then starts to tighten, but not like the rear which nipped up - and you can hear the grit in the threads grinding - thats where I stopped! I have a torque wrench, and although I cant fit it on the plug, I have a feel for the correct torque setting, and I dont think that the plug is quite there, just a bit looser - but obviously dont want to keep tightening and do some damage to the threads.

Just as a matter of interest, how far in does the plug have to be to ignite the fuel efficiently? - The bike runs fine - well, prob better that before I replaced the plugs - still some snatchiness at low revs, and a bit of a surge when I open the throttle but am putting that down to; TPS mod req'd, throddle boddies requiring sync etc.

Dont think this is related to the plugs? do you?

Re: Front Spark Plug
 

lol no - example of a discussion the other day with my girlfriend:

me: I wanna get a new exhaust
her: Why? whats wrong with the one on it?
me: I want to hear the rumble of the v twin engine - and it'll look better...
her: oh...think its a waste of money
me: and its safer too - cos motorists can hear you, if they might not have seen you...
her...hmmm...whats the loudest one you can get? is the fuel loud enough? I think you should go louder...if it means you are safer

Gotta love her!:thumleft:

Re: Front Spark Plug
 

It has to be in the chamber properly, 1 or 2mm further out won't harm the ignition, but id be worried about any exposed threads getting hot and causing preignition (but im mechanically paranoid, ask dizzyblonde lol)

If it goes in most of the way with finger pressure then you're most of the way there anyway.
you do know that the washer on a new plug is supposed to be "squishable" by about half a turn anyway? (new ones only, ones already tightened nip up straight away)

Edit: from your earlier post, new plugs probbly mean better combustion and a bit smoother, but probably nothing to do with the snatchiness.

What I would do is; bottle brush the threads, forget about any crap in there, will only be a tiny bit, lots of WD40, then add coppaslip to the plug and tighten it as you normally would.
Once the thread is in a fair way then the normal torque will not strip it even if there is some **** in there

(All IMHO, and my favourite tool is a big hammer, you should probably consult a suzuki dealer and give them lots of money. Right thats me fully disclaimed!)

Re: Front Spark Plug
 

Thanks for your help - yeah know that the washers compress, I reckon it is sitting about 1 or 2 mm proud of the washer seating against the cylinder head properly - I could keep turning it but dont think its a good idea. I'll try to get the rest of the crud out and see how I go.

Re: Front Spark Plug
 

Billy, a trick for cleaning crud out of threaded holes is to hacksaw a few slots along the length of a bolt (in your case use the old plug), when screwed in the slots collect the crud, it acts a bit like the flutes in a tap when tapping new threads in a hole.

Re: Front Spark Plug
 

I totally agree! and NEVER use a wratchet to start always start by hand, get a bit of plastic tubing over the end as an extention. Basically you can't cross thread if you can turn even half a turn by hand. Once you've gone as far as you can by hand remove the tube and get the wratchet on it. I've never used a torque wrench just seat the plug by 1/8 turn once it's hit bottom to compress the gasket on the plug then back it off and reseat once reseated, go 1/8 turn. After running at temp it a good idea after cooling to repeat the last bit. It's always worked a treat for me.

Re: Front Spark Plug
 

Not a bad idea but the word hack saw and threads is alarming just make sure you tidy up the threads before you put them in the head a few nasty burrs can really **** things up :smt103

Re: Front Spark Plug
 

well...did the tps mod today - thought everything was ok.

Let the bike cool, then thought I'd start her again to see how she would run from cold - the tickover was all over the place, then started running on only the rear cylinder. In my mechanical ineptitude, thought it must be the TPS mods that caused the cafuffle... so reset that, still no joy. Put my brain in gear and removed the front plug (which I knew wasnt seated properly), and it was soaking wet (prob after a rather exhuberant cleaning session which involved cutting the paintwork, polishing then auto glym high gloss protection - around 4 hours of my life gone!) - thought it would be a good idea to clean the threats in the cylinder with a toothbrush and WD40 - did this, and removed loads of crud - the plug goes in a lot sweeter now - I reckon only a turn or so from fully nipped up.

So nowI have a bike running on 2, but with no TPS mod ! DOH! - Job for the morning I think!

Unfortunately we have the (to be??) inlaws up, and the gf want to go the the Eden Project with them tomorrow - tried to explain that I really want to go out on the bike (looks like the first dry day for a week) - went down like a sack of s**t!!

Muchos grovelling to do me thinks...

Mind you - still not idling great - im putting that down to the newly installed Fuel can...

Chin up...

Re: Front Spark Plug
 

Did you get the fire belching from the WD40? lol

Have you tried; clean threads, screw plug in carefully, remove plug, clean threads again, repeat...

Just something I'd try to get it that bit further in to get the compression up...

Re: Front Spark Plug
 

Ooooohhh yes....done it about 15 or 20 times now - every time a little bit further...

Still gets a bit tighter at the end - about the weight of my arm on a 6 inch spanner - not forcing it - too scared of stripping the threads - but not seated yet - mind you, the plug cap fits almost as good as the one to the rear pot tho - I think I'll keep doing it over the next few days, then once its in change the oil, just incase and crap has gone in....shame as I only changed it 200 miles ago, but not worth the damage for 15 quid of Silkoline...

Re: Front Spark Plug
 

IMO you can use more force than that, especially with so much thread already engaged

Edit: but still, keep washing it out, its better to get a clean engagement

Re: Front Spark Plug
 

Oh yea, was funny, the outlaw, sorry, father in law to be (sometime in the not time-defined future) was stood behind as I started her up after putting half a gallon of WD in the front pot - nearly took his eye brows off!!! - dont think he'll pay for the wedding now....every cloud has a silver lining....lol only kidding!

Re: Front Spark Plug
 

Lol! nice one!

My mate shat his load when I cranked his cage up after the same trick, that was Duck oil penetrant spray too, bit more volatile :smt077

Re: Front Spark Plug
 

You reckon? - its definately not threaded - have maybe done 10 turns easy...but is starts to...errrr...creak, I think is the best way of describing the noise....as I turn the plug in - there is resistance, but not that much - strangely enough, if I kep turning its ok, but if I stop, then start, the initial resistance is much higher...

Re: Front Spark Plug
 

Bet his pants needed some Vanish!!

Re: Front Spark Plug
 

That could well just be corrosion left from the old plug, after 10 turns you would have to be a real gorrilla to bugger the threads.

Vanish? they nearly needed the fire brigade, he was stood right next to the exhaust! teehee

Re: Front Spark Plug
 

you reckon it could be ok to exert a bit of force then? Obviously so worried about stripping the threads, but my common sense tells me that so much thread is already engaged, that it is unlikely.

The plug I took out was not in the best of nick (thread wise) so I think you could be right.

Re: Front Spark Plug
 

A bit more force, obviously don't stick a cracking bar on it, but you can use more than the weight of your arm, you could even be feeling the washer beginning to crush.

Re: Front Spark Plug
 

Aye, you could be right - just comparing the force when I changed the plug on the rear - that went in dead easy (obviously no road crud in there!)

Just dont want to hurt the old girl!

you done the TPS mod then?

Re: Front Spark Plug
 

Mines black and curvey, next is to cut the middle of the air filter out and increase the jet size.

(See, jets, nice brass things, fluid mechanics, none of this electrical jiggerypokery :D)

Re: Front Spark Plug
 

F#cking hell, listen to me... you wouldnt know I'm only 18!!

Eeeeek!

Re: Front Spark Plug
 

lucky bugger - stop bragging!