Spark plug doesn't want to seat ?!

[Recreateme]

I just finished up my Carb work, and decided to check my spark plugs. I pulled out the right side plug smoothly, it looked good, i had no trouble putting it back in. I pulled out the left side smoothly and it looked good BUT

I went to insert it back in and started screwing it and it seemed to be pulling to the front of the bike (the left) and it become VERY hard to screw in ( i thought that didn't seem right) so i unscrewed it, and tried again. It did the same thing.

I decided to try very lightly just to screw it in without doing anything but turning it with my fingers and it doesn't want to catch anywhere, except when it pulls to the left.

Is this normal? If not how should i proceed?

After trying many times i gave up for the night... I didn't want to get frustrated and break something or make it worse..

 

[Greasey Fingers]

Sound like its stripped (spark plug hole) try retapping it, I had ti do mine and it worked fine. Failing that helicoil it.

heres an example of the retapping tool, just need to find the right size: http://www.ebay.com.au/itm/18mm-1-5...t=Motors_Automotive_Tools&hash=item20ccc35825

 

[Recreateme]

damnit...

Thanks.. I was really afraid of that.. it looks like only the first few threads that are damaged a bit..

Tomorrow I am going to pick up a m14 thread chaser and try to see if i can fix them, otherwise i guess i will need to get a tap and insert kit...

From what i can gather it should be an m14 spark plug hole, so any m14 kit should work right ? Also i see in my manual its a 3/4" reach so thats the size insert i will need right ?

 

[Greasey Fingers]

I don't remember sizes off the top of my head so I cant say for sure, but if the manual says so ill would run with that. Just compare your spark plug to the tread chaser too to get an idea. And don't worry if you loose the first few threads as long as you get the rest your fine. I lost about half my thread, but the rest came good and the plug goes in fine A good thing to do is put some grease on the thread chaser tool so any metal fragment stick on that when you pull it out. My head was off when I did mine so I didn't need too, but the mechanic I talked to said if it was on to do the grease thing.

 

[Alex_D]

Another good thing to do is to rotate your crankshaft manually so the piston sits at its highest point, that way you make sure no metal shavings fall inside your cylinder and once you are done you can just use a little magnet as a precaution to make sure you removed everything

 

[Recreateme]

Thanks guys,

I didn't think Aluminum was magnetic? (or do XS400s have a different material head?)

I plan on trying to chase with a greased up 14mm chaser... When i look through the hole i can see that only maybe the first 3-5 threads aren't in great condition, mostly on the left side (which is why it pulled left)

If i can just sort that out the rest should catch afterwards... This is so frustrating though! lol

I was done for the night too, ready to pack it in and thought "Ya know, i never did look at the spark plugs.." and then this happened... geez.

 

[frwinks]

m14 1.25 pitch

use grease on the tap and blow the rest of the shaving out either with compressed air, or just turn the engine over a few times..the head is al

 

[Recreateme]

Perfect, Thanks!

I can pick up a kit and grease at Canadian Tire on my lunch and try it out after work.

 

[willem]

duct tape a straw onto your vacuum cleaner end, and clean out your cylinder with that. Just in case

 

[Recreateme]

I'll see if I have a few crazy straws laying around lol Thanks for the tip, its useful and fun!

 

[Alex_D]

Thanks guys,

I didn't think Aluminum was magnetic? (or do XS400s have a different material head?)

Lol my bad!
I was going from experience on working on a car, that didnt have aluminium heads
The piston trick is still useful to do with the vacuum and straw I guess

 

[Recreateme]

No worries, I have read about cranking the piston a bit to blow the scraps out of the spark plug hole, that seems like a 'must do' just to be safe. I have also read that the aluminum is so brittle and flimsy that even if small pieces get into they burn up fairly quickly without causing damage anyway.. I would imagine thats only if a couple get in, not all of them haha

 

[Recreateme]

UPDATE:

Yesterday i bought a 14mm thread chase, and i didn't seem to do anything, it too just spun in the hole and didn't go it or catch anything.. So i assume this means it didn't work and i need to retap with inserts..

I have been looking at the Sav-A-Thread system (by helicoil) its a 14mm x1.25 pitch system with inserts, but i can't find anything stating the length of the inserts, i know i need 3/4" but am not sure if it comes with one of that length, anyone know?

Anyone know if this system works?

 

[frwinks]

the insert you're looking for is R5326-14L You can buy singles from NAPA if one doesn't come in the kit. When threading it in, put a THIN coat of JB weld on the threads

 

[Recreateme]

I called NAPA in my town and they have to order the kit but part source has a kit in stock so ill check that out and try retapping the hole tonight.

There is no way I can screw this up right? Lol

Centre the tap, screw it in slowly with some grease, back it out regularly to clean the shavings, install new insert on plug, slowly screw in. Done. Right?

Paranoid ill mess this up and have no bike :S

Posted via Mobile

 

[Recreateme]

Just to update, I bought as rethread kit from Part source, I only had to begin to rethread the first 5-6 threads, which were the damaged ones, this enlarged them to allow the spark plug to skip them and screw into the remaining threads. I didn't have to use the inserts at all yet.

 

[Greasey Fingers]

good job

 

[willem]

nice!

did you end up using the straw on a vacuum cleaner? I haven't tried it myself just wondering if it actually works

 

[Recreateme]

Willem, i did not try the straw taped to a vacuum cleaner trick as i didn't have to re thread the whole plug and as such i had far less shavings. Most of my shavings were picked up on the grease from the tap fairly nicely.

Some did get blown in, but I am hoping it wont be a problem...

I think maybe the straw would fair better being attached to a dustbuster, or even getting a rubber tube and attaching that to the dustbuster. It would be bendy to get in the there a bit better..

 

[xschris]

Good to hear you fixed it