01 RM250 broken plug

R

Rickster

Member

Aug 21, 2005

12

0

• May 24, 2006

• #1

I have a problem with the ground electrode breaking off in the above bike. It is supposed to have had extensive modifications, but the previous owner was very vague about them, so I took it with a grain of salt.. Has a br9ev plug in it. Any tips as to how to check the squish and what the min acceptable squish spec is? Is there different thickness headgaskets available for this bike? I`m thinking squish is too close, but any other ideas to check would be appreciated! ( I mix 40:1 belrayhr1 w/93 octane fuel)Thanks.

 

oldfrt613

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Member

Jun 29, 2005

443

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• May 24, 2006

• #2

Check your manual - I believe that RM requires a special plug with a heavier electrode. If the head has been milled, it very well may need a plug spacer.

 

sick 96 250

Damn Yankees

Member

Jul 16, 2004

1,207

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• May 24, 2006

• #3

I run a br8es in my 99 rm and in my 96 rm when i had it with no problems. Whatever is causing your situation needs to be situated ASAP though

 

oldfrt613

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Jun 29, 2005

443

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• May 24, 2006

• #4

If I remember correctly, ( and this is the case with the newer CR's ) on some models due to combustion turbulence the electrodes on standard plugs will break off. In any case - see what the reccommended plug is from a Suzuki manual or Suzuki dealer NOT a general parts retailer - my local parts dealer shows standard plug for my CR which is not correct.

 

robwbright

Member

Apr 8, 2005

2,283

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• May 24, 2006

• #5

My RM takes a $23.00 plug. I believe the 250 is the same. It is specially designed for the bikes. It may not be completely necessary, but given the stories I've seen of the electrode breaking off, it's worth it to me.

I used one for 9 months last year with no problems.

 

oldfrt613

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Jun 29, 2005

443

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• May 24, 2006

• #6

Honda's special plug is $5.00. It does have a heavier electrode. I contacted NGK to get an irridium cross over and was told to only use the heavy electrode unit. Since I am of the opinion that broken metal pieces in an engine is a bad thing - I'd spring for the $ 20.00, somehow I think it would be cheaper in the long run.

 

R

Rickster

Member

Aug 21, 2005

12

0

• May 24, 2006

• Thread starter
• #7

The manual shows the factory plug as being a BR8EG. The only difference from a EG to an EV plug is the material used in the center electrode(nickel vs gold) if I am reading the ngk chart correctly. If there is an updated plug # I would love to have it, as my local dealer tells me the same thing my book does. I am still concerned that I should be verifying the squish while the head is off.I have never done a squish measurement(or had to) before,what is the best way to check it? Thanks again.

 

C

chevy383cid

Member

Aug 26, 2005

307

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• May 25, 2006

• #8

Smear a small amount of oil on the piston top and bottom of head, apply a small amount of molding clay to the piston top-smear it out evenly-move piston down in the bore about an half inch(but stop before the egxuast port!!!) install the head gasket,head,and plug and snug the head bolts down-Now move the piston up in the bore(slowly)by hand using the flywheel -to top dead center and back to the half inch below tdc just as before assy.you can use a majic marker and make marks from flywheel to case so you know just where thease two spots are!!-remove the head gently and use a pair of calipers to measure the squash area_look close at the area that your plug intrudes into the cylinder!!Do a search on squash clearance min.for your bike.

 

M

muddy226

Sponsoring Member

Sep 14, 2003

271

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• May 25, 2006

• #9

I thought that the Suzukis had to have the special plug due to the harmonics or whatever causing just that sort of breakage. They are very expensive but seem to last for ages, I've never changed one through necessity, but usually put a new one in when changing the piston.

 

sick 96 250

Damn Yankees

Member

Jul 16, 2004

1,207

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• May 25, 2006

• #10

Never heard that about all zuki's? I have never used anything but the br8es from pepboys and always had good luck. Could the head gasket be to thin or something maybe?

 

M

Micahdawg

Member

Feb 2, 2001

503

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• Jul 10, 2006

• #11

The suzuki's call for an "R" plug to protect the CDI or coil or something. The resistor in these plugs does protect the electronics. But I think you can run different flavors of R. Like a BR8ES, BR8EV, BR8EG, etc... My manual calls for a BR8EG which is just the a finewire (more expensive) electrode. I use the BR8ES's because they are cheaper and I already had some on hand. But I would definitely not use a B8ES....just make sure you get the R's.

Micah