Jump to content
IGNORED

Plug fouling question


pennboy

Recommended Posts

I recently had the 600 mile service done on my new RT and was told that the "2nd set" of spark plugs were fouled and replaced under warranty. Any ideas on why the "2nd set" would foul ? I rode the bike according to the BMW break-in procedure.

Link to comment

It's fairly common, especially if the bike is ridden easy as part of a break-in procedure. Now, get out there and RIDE it. Hard. The boxer loves to be revved far more than any other twin. Don't be afraid to bump up against the rev limiter every once in awhile and the plugs will be fine.

Link to comment
It's fairly common, especially if the bike is ridden easy as part of a break-in procedure. Now, get out there and RIDE it. Hard. The boxer loves to be revved far more than any other twin. Don't be afraid to bump up against the rev limiter every once in awhile and the plugs will be fine.

 

+1

 

Give it some grief regularly and it will like it. You should also use a quality fuel. Top Tier Fuel standards site.

Link to comment

There are only two common things that will cause plug fouling. There were 3, but now that there is no lead in gas, it is down to 2.

 

1. Oil fouling caused by oil burning. Unless you are going through a quart in 1000 miles, then this is not the problem.

 

2. A plug that is too "cold" a hear range for the type of driving you do. This causes carbon deposits on the plug. As others have stated, one answer is to drive with more gusto.

 

When I was first riding in the '60s, my bikes were 2-strokes. They suffered commonly from both of the above; so much so that I had 2 heat ranges of plugs. One for city use and one for highway use. But back then, every gas station has a plug sandblaster, that cleaned them up in 30 seconds just like new. Now, we throw away perfectly good plugs that only have a light film of carbon on the electrode. confused.gif

Link to comment

There's no way driving easy will cause plug fouling. The oxygen sensor(s) aren't working correctly and/or the control box/brain is programed wrong or........

 

It's extremely difficult for me to believe you dealer didn't find and correct the fault..........As ole Willy said, 'something is rotten...'

Link to comment
There's no way driving easy will cause plug fouling. The oxygen sensor(s) aren't working correctly and/or the control box/brain is programed wrong or........

 

It's extremely difficult for me to believe you dealer didn't find and correct the fault..........As ole Willy said, 'something is rotten...'

 

The oxygen sensors and fuel maps only control fuel burn and along with the knock sensor control knock. If you get dirty fuel none of those systems will prevent plug foul. By running the engine at higher revs and keeping the temperatures in the cylinder heads higher you prevent some of the buildup by keeping the unburnt fuel to minimum. This won't help if your fuel is dirty. And deposits that are there aren't likely to leave without some help from deposit removing additives. In the end, engine timing can cause plug foul but I would expect the check engine light to come on due to the management system not being able to control the fuel mixture within tolerances.

Link to comment

I have read that the secondary plugs do not fire all the time and that generally they will look dirtier than the main plugs. Assuming that is the case then the gentle riding during break in and maybe some bad gas caused them to foul. It may also be that they just looked worse than they should so the dealer replaced them as precaution.

Link to comment

Thanks all, for your responses. Once the weather breaks here and I can get back in the saddle I'll ride it harder and see if there's an improvement. I did notice that when I had the RPMs up the machine seemed to like it better.

 

Jeff

Link to comment

As a rule of thumb my mechanic told me to never shift below 4,000 rpm. I've got 7,500 miles on the bike and it still feels like it is breaking in. Don't be afraid to take this engine to the limit. It was engineered to handle the stress. Like any thorougbred it needs to stretch its legs everyone once in a while.

Link to comment
As a rule of thumb my mechanic told me to never shift below 4,000 rpm. I've got 7,500 miles on the bike and it still feels like it is breaking in. Don't be afraid to take this engine to the limit. It was engineered to handle the stress. Like any thorougbred it needs to stretch its legs everyone once in a while.

 

At 7,500 miles your bike is about half way to broken in. The BMW boxer engine is intended to go a long way.

 

Andy

Link to comment

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...