Triumphrat

zippythehog

INTRODUCTION:
The Subject is a 96 Sprint. So I thought it best to change the airfilter. You must take the carbs off to change the airfilter....hmmm. Well while I'm here I thought to adjust the valves, and check the plugs.

BODY:
After pulling the plugs, I find them all the wrong heat range- all cooler. The one and three are 9ea-9, number two cylinder is 9ea. The middle one has a lot of soot and a weird grey/brown mass on one side of the electrode. Only number three looks sort of normal.

QUESTION: Anybody have any idea why the previous owner or mechanic did this? Mileage is mediocre at best (36mpg).

Also, has anybody heard anything wrong with using used shims (measured & confirmed thickness with a mic) on the motor?

Thanks,
Zip

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Cerberus

cooler plugs reduce the likelyhood of pre-ignition or electrode melting. the middle cylinder normally would be hotter becuase of it being surrounded by hot cylinders, so it is not unheard of to run cooler plugs in inboard cylinders, but it is normaly not neccesary.

36MPG implies that is running a bit rich, and that may be because of the air filter(s?) being dirty.. I wouldn't make any adjustments to your mixture before you do the shims and plugs and filter.

the weird grey/brown mass is probably evidence of a bit of oil burning.

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flatspins

As long as you measure each shim there is nothing wrong with reusing them.....provided they don't have any deformities or serious wear on them.

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zippythehog

Thanks all

__________________
"You don't know what you don't know."