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post #1 of 12 (permalink) Old 04-09-2019, 11:24 PM Thread Starter
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LT MAP Tubes and flat spot issue.

I have a problem with a flat spot. Whilst cruising at 50-60 km/h in second gear the power will suddenly die, like someone has turned off the fuel. Engine still runs and if the throttle is held steady the RPM's will fall and then it will kick in again. Same thing happens at about 70-80 in third if trying to hold a set speed. Changed the TPS, no difference. I believe it could be the MAP sensor tubes. Have been trolling through this forum for pics or other issues but there are so many topics on here it is very time consuming and I am getting no where. Anyone point me to a pic on a thread or a diagram about these tubes please and does/did anyone else have this issue? HELP
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Die hard LT owner - you have to be with all the issues mine has had. :-)
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post #2 of 12 (permalink) Old 04-10-2019, 01:16 PM
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I can't help with the problem you describe but I don't believe it's related to MAP tubes. At the speeds you mentioned the engine will be turning ~3000 rpm. From my experience on my 2010, leaking tubes cause problems at idle and poor throttle response below 2500 rpm.
You can see a drawing that shows the MAP tubes on bikebandit.com. Each tube consists of 5 pieces, 3 rubber connections and 2 hard plastic tubes. Do yourself a favor and get rid of the stock Triumph tubes and replace with single piece flexible tubing and tube clamps at each end.
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post #3 of 12 (permalink) Old 04-10-2019, 09:58 PM
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Ditto on getting rid of the stock MAP tubes.....
Saddlebags certainly better than the stock ones...
Noted the V&H exhausts....assuming a dealer did the download?
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post #4 of 12 (permalink) Old 04-13-2019, 04:32 AM
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I have problem with mine as well. I have put new vacum tubes on with no joins cut to the same lenght each side. I replaced them after my issues started.
My bike idles fine and runs great under power and also above 3000rpm. The problem is with the throttle just open. Just above idle between 2000rpm and 3000rpm. It will stutter and miss to the point of stalling. It is worse going down hill when you are just holding the throttle open to hold speed.

I have had it plugged into tuneecu and cant find any faults or anything out of the ordinary. I have reloaded the map with no change. I believe it is running rich but i cant now for sure.
To try and make it rideable i have reconected the O2 sensers and loaded a modified map. It is better but still has the same issue just not as bad.

I want to work out the problem and get it back running properly with the O2 SENSERS.

Last edited by Midlife; 04-13-2019 at 04:37 AM.
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post #5 of 12 (permalink) Old 04-15-2019, 01:04 AM Thread Starter
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Quote:
Originally Posted by jaknife View Post
I can't help with the problem you describe but I don't believe it's related to MAP tubes. At the speeds you mentioned the engine will be turning ~3000 rpm. From my experience on my 2010, leaking tubes cause problems at idle and poor throttle response below 2500 rpm.
You can see a drawing that shows the MAP tubes on bikebandit.com. Each tube consists of 5 pieces, 3 rubber connections and 2 hard plastic tubes. Do yourself a favor and get rid of the stock Triumph tubes and replace with single piece flexible tubing and tube clamps at each end.
Thanks jaknife, sounds like sound advice

Die hard LT owner - you have to be with all the issues mine has had. :-)
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post #6 of 12 (permalink) Old 04-15-2019, 01:06 AM Thread Starter
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Originally Posted by slingshot60 View Post
Ditto on getting rid of the stock MAP tubes.....
Saddlebags certainly better than the stock ones...
Noted the V&H exhausts....assuming a dealer did the download?
The bike runs a PC5. It has been on a Dyno and even they couldn't work out the problem.

Die hard LT owner - you have to be with all the issues mine has had. :-)
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post #7 of 12 (permalink) Old 04-15-2019, 01:10 AM Thread Starter
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Quote:
Originally Posted by Midlife View Post
I have problem with mine as well. I have put new vacum tubes on with no joins cut to the same lenght each side. I replaced them after my issues started.
My bike idles fine and runs great under power and also above 3000rpm. The problem is with the throttle just open. Just above idle between 2000rpm and 3000rpm. It will stutter and miss to the point of stalling. It is worse going down hill when you are just holding the throttle open to hold speed.

I have had it plugged into tuneecu and cant find any faults or anything out of the ordinary. I have reloaded the map with no change. I believe it is running rich but i cant now for sure.
To try and make it rideable i have reconected the O2 sensers and loaded a modified map. It is better but still has the same issue just not as bad.

I want to work out the problem and get it back running properly with the O2 SENSERS.
Yes it is a mind scrambler. Only happens with the throttle just on (say 5%). It is like it floods. If you hold the throttle steady, it will decelerate to a point where it fires up again. It is very annoying. Unfortunately we don't have a competent dealership for hundreds of miles due to the ever increasing closures.

Die hard LT owner - you have to be with all the issues mine has had. :-)
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post #8 of 12 (permalink) Old 04-15-2019, 01:12 AM Thread Starter
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Quote:
Originally Posted by slingshot60 View Post
Ditto on getting rid of the stock MAP tubes.....
Saddlebags certainly better than the stock ones...
Noted the V&H exhausts....assuming a dealer did the download?
Tsukayu strong bags are awesome. The OEM leather bags are garbage - good riddance to them

Die hard LT owner - you have to be with all the issues mine has had. :-)
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post #9 of 12 (permalink) Old 04-15-2019, 03:02 AM
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Quote:
Originally Posted by Scoobersteve View Post
Yes it is a mind scrambler. Only happens with the throttle just on (say 5%). It is like it floods. If you hold the throttle steady, it will decelerate to a point where it fires up again. It is very annoying. Unfortunately we don't have a competent dealership for hundreds of miles due to the ever increasing closures.
Agree with that 100%.....mine does it as well, no logic, intermittent.....has cut out on busy highways.....so far luckily pull the clutch and hit the starter. Waiting for that time it won't start and I'm the cause of an accident.

We are fortunate to have Hermy's close by and another one....the third one just closed within the last 3 months and is in process of auctioning off everything. Aprilla, Triumph, Ducati & Moto Guzzi. Additionally the Indian Dealer which occupied a defunct HD Dealer Building is gone. The market/lack of it has changed so dramatically since 2006....and never recovered.

Back to the issue....I'll stick my neck out and state my suspicion is it may be related to strict emission controls and the ECU they locked starting in 2014. You can't program/do anything with them.

Heard good things about brand of saddle bags mentioned. Been thinking of Boss Bags to retain the leather look but they are expensive with good quality.

Heard mixed things on the PC5, specifically if the ECU is shutting off the fuel they won't do a thing on 2014's and above...True or not I don't know. Personally don't wish spend the $$ for one.

Last edited by slingshot60; 04-15-2019 at 03:21 AM.
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post #10 of 12 (permalink) Old 04-16-2019, 10:13 AM
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The problems you guys describe sound similar but Slingshot cutting out at highway speed is different. My only guess on that issue would be a loose ground.
Have ya'll checked the gap on your sparkplugs? The book recommends 0.9mm. The problems described, (accept for cutting out at highway speed), sounds similar to what mine did after I changed plugs the first time. I also got a check engine light. I thought I didn't connect something or I got a bad plug so I changed them again with 4 new plugs gapped at 0.9. Same problem. I measured the gap on my original plugs and they were about 0.75mm. So I did it again with 4 more plugs gapped at 0.8mm. The light went away after 3 heat cycles but I still had an issue with throttle response. I reasoned that the gap had opened up because of wear so I did 4 more plugs at 0.7mm. Problem solved.
If somebody told me this I would have my doubts but it really did happen to me. This all happened at about 20k and I have changed my plugs 3 times since then. Still using 0.7mm gap and going strong at 90k.

Last edited by jaknife; 04-16-2019 at 10:19 AM.
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