Engine over revs following restrictor plate removal

[Rammy]

I run a 2008 1200L, which for the first 1500 miles ran with a restrictor plate to reduce air flow and thus power. recently when I had the bike undergo it's first service I had this plate removed and also fitted V&H slip on's :D.

I've noticed since that the bike is not able to regulate the engines rpm correctly in line with the throttle when its been held at a low throttle for several minutes. When the clutch is applied and the bike brought to a halt the engine races for 10 - 15 secs before slowly dropping down to the correct idle. This also causes the engine check light to come on for several seconds.

Took the bike back to local harley shop, who cleared the fault code, but could find no problem or supply any answers. Problem still remains though and if anything is getting worse. Certainly with the new V&H's its a very noisy problem

I'm starting to think along the lines of ECU re-map to solve, or adding a Fuel pak. Has anyone else had similar problems and found a solution?

[Folkie]

Welcome to the Forum, Rammy. I've not heard of anyine having this problem before. Hopefully someone'll be along soon with some ideas.

[jimmyess333]

It sounds like a vacuum leak at the throttle body to intake gasket or intake to head gasket to me.
Was the gasket replaced when the restrictor plate was removed?

[Rammy]

Interesting idea. It's unlikely that the gasket was renewed as dealer made no charge for removing the plate. It also reminds me that the exhaust header bolts were missing on one pipe when I got home which may have damaged that gasket too.

Tonight I took a look at the HT leads, and the top of the plugs was found to be oily. Need to get a spark plug wrench and take the plugs out. They should have been changed at the service, but dont appear to have been: frownthre

[ray1970]

Restrictor plate? Why did your bike have a restrictor plate? Where was this restrictor plate installed on the bike? Was the ECM recalibrated when this restrictor plate was installed? Sorry for all the questions but I have never heard of a restrictor plate on a motorcycle and am just curious to know more. Thanks.

[Takingabreak]

The restricter plate is on the European models.

As to the Idle speed, It would be my guess you did nothing to correct the air/fuel ratio after you uncorked it.
The ECM is programed to hold the iac (Idle air control) open a certain amount to prevent stalling, and it will hold it open longer if it senses a over rich condition.

May I suggest you get a Vance and Hines Fuelpak to correct the now extreme lean condition before you damage your engine..

[Quay]

It's seems like a warranty issue. If the dealer removed the restrictor plate as legally permitted, it's their responsibility to correct the inferior operation, which may include a factory authorized re-map for that process? Removing the temporary restrictor plates is nothing new and mystical (if I correctly grasp your motor-laws).
The V&H units are a different matter and may contribute to the problem. Reverting to the stock mufflers for the moment, until the dealer corrects THEIR SUBSTANDARD WORK, should be the first priority.

[krono]

Hello, I had somehow the same problem. After I changed to Screaming Eagle slip ons with my own mod, I had faster idle and about the same symptoms as you.
I solved it last weekend when I added O2 killers that came with my PC III (that I just managed to install about 15 minutes ago, now trying to make the seat fit, for 2nd time, this time helping myself with a dremel :P )
So, what I would suggest is to put some O2 killers on the sensors, and see if it helps.

[Folkie]

Restrictor plate? Why did your bike have a restrictor plate? Where was this restrictor plate installed on the bike?It's a licensing thing. If you take your test on a 125cc bike, you're restricted to no more than 33 bhp for two years. On my carb bike the restrictor was between the carb and the inlet manifold:

http://xlforum.net/photopost/data/500/Restrictor.jpg

[Ireeman]

It's a licensing thing. If you take your test on a 125cc bike, you're restricted to no more than 33 bhp for two years. On my carb bike the restrictor was between the carb and the inlet manifold:

http://xlforum.net/photopost/data/500/Restrictor.jpg
Glad you cleared that up folkie, i was stumped. restrictor what?

[Folkie]

I run a 2008 1200L, which for the first 1500 miles ran with a restrictor plate to reduce air flow and thus power. recently when I had the bike undergo it's first service I had this plate removedRammy, did you finish your two years, or did you take your test again under Direct Access, or … ?

[ColinB]

I run a 2008 1200L, which for the first 1500 miles ran with a restrictor plate to reduce air flow and thus power. recently when I had the bike undergo it's first service I had this plate removed and also fitted V&H slip on's :D.

I've noticed since that the bike is not able to regulate the engines rpm correctly in line with the throttle when its been held at a low throttle for several minutes. When the clutch is applied and the bike brought to a halt the engine races for 10 - 15 secs before slowly dropping down to the correct idle. This also causes the engine check light to come on for several seconds.

Took the bike back to local harley shop, who cleared the fault code, but could find no problem or supply any answers. Problem still remains though and if anything is getting worse. Certainly with the new V&H's its a very noisy problem

I'm starting to think along the lines of ECU re-map to solve, or adding a Fuel pak. Has anyone else had similar problems and found a solution?

mmm...this is going to feel like I'm talking to myself...:D

If the dealer installed the restrictor plate on delivery, and the dealer removed the restrictor plate at the service, then the dealer should ensure the bike is running properly - 'fit for purpose' as the UK consumer rights calls it. Don't add anymore bits to it to try and mask the problem.

The restrictor plate doesn't affect low throttle running (MrsB ran with a restrictor plate on her Virago for two years), the bike will be getting all the air it needs, it just restricts the higher throttle opening when, even though the butterfly valve is wide open, only enough air can flow to make 33hp.

As you're getting an engine check light you could pull the error codes (here's how to) and let us know what you get...that might help.

The dealer's caused it, the dealer should fix it. Don't be happy with anything less.

[Folkie]

Couldn't agree more.

[Gone]

restrictor plate .. 33 HP for 2-years ... only in the government mind set.

[Rammy]

Yep, I had a restricted license hence the plate.

It was located in the same place as the pics, although of course my bike is EFI. No remap of the ECU was performed by the dealer, so this may be the issue, although I thought that ECU's learnt after a few miles and changed their mixture dynamically. Have now done 800 miles since plate was removed, and if it is the ECU then it definately needs to be reset.

On the O2 killer or V&H Fuel Pak side, I am no expert. Are these addressing the same issue in the same way, or tackling different problems to try and find the solution.

[Swankster]

The restricter plate is on the European models.

As to the Idle speed, It would be my guess you did nothing to correct the air/fuel ratio after you uncorked it.
The ECM is programed to hold the iac (Idle air control) open a certain amount to prevent stalling, and it will hold it open longer if it senses a over rich condition.

May I suggest you get a Vance and Hines Fuelpak to correct the now extreme lean condition before you damage your engine..


I would listen to J.tunes suggestion.
Don't ask...
Swankster

[Folkie]

No remap of the ECU was performed by the dealer, so this may be the issue, although I thought that ECU's learnt after a few miles and changed their mixture dynamically.On my carb bike no tuning of the carb was done either, and it ran fine. It still ran fine when the restrictor plate was removed.

The restrictor shouldn't make any difference to fuel mixture. It is limiting the anount of air and fuel at wider throttle openings, which shouldn't make any difference to the mixture between the two. At smaller throttle openings (and in particular: at idle) it makes no difference at all.

[ray1970]

Thanks for the restrictor plate info.... I live a sheltered life here in the U.S.

[Folkie]

Thanks for the restrictor plate info.... I live a sheltered life here in the U.S.Plenty of people in the UK have never heard of them and don't believe they exist! :wonderlan

[krono]

If I had a restrictor plate law here I think I would remove the thing as soon as I get home...

[Folkie]

If I had a restrictor plate law here I think I would remove the thing as soon as I get home...It's a bit like boring your engine out to 1200 but still insuring it as an 883. You probably won't get found out, but if you do you aren't insured, and apart from the fact that you're riding illegally (for which there would be a fine and you may be banned from riding), there could be a hefty bill to pay. Just say a person was injured in an accident; there could be a huge bill to pay in personal injury compensation. Is it worth the risk?

[krono]

It's a bit like boring your engine out to 1200 but still insuring it as an 883. You probably won't get found out, but if you do you aren't insured, and apart from the fact that you're riding illegally (for which there would be a fine and you may be banned from riding), there could be a hefty bill to pay. Just say a person was injured in an accident; there could be a huge bill to pay in personal injury compensation. Is it worth the risk?

Yes, that is very true. Anyways you should come here for vacations and check youself the kind of anarchy that rules the streets here ... pretty crappy imo, last year my mom got her car crashed and the bastard did not had insurance, still trying to charge him... anywyas, the ammount of illegal stuff done here to vehicles is amazing... hell, I was today chopping my license plate :banana

[Urrell]

Took the bike back to local harley shop, who cleared the fault code

The fault code shows the cause of a problem. The should have sorted it not just cleared it, but it seems they are hoping the fault code does not show any more!

[Rammy]

Yes, in hindsight it was pretty lame just to clear the code. They had spent a couple of hours trying to establish why the code was showing, and in the end took the easy way out by clearing it and then using the "Hope it does not re-occur" fix.

It will be weekend now before I can update further, but I will see if they kept a record of the fault code and let you all know. Thanks for the feedback, and if nothing else wev've all learned not to drive in ARGENTINA :D