[Doug25]

My '86 T16 is suffering from what seems like a flat spot from about 1750 - 2500 rpm, or until the boost kicks in. Most noticable in 2nd and 3rd before the boost snaps my neck and 'healthily' sits mid way through the red.

Recently, the flat spot has turned to rough running, kind of jerky. Not undriveable, in fact it's fine below those revs and at idle, also under boost, but enough to make it unpleasant to drive - like it's about to run out of petrol!

Any thoughts?

As an aside, the rev counter works only about 50% of the time, and about 20% of that time it jiggles around, momentarily trying to reach the revs being produced at that time. Just a bad connection or might there be some other problem that is causing this?

Cheers in advance.

 

[NSE]

I would start by checking the ignition timing and the spark plug condition.

 

[Doug25]

Plugs are new, and timing ok too...

 

[philb]

Ok, but the thing is to check the condition. What did the old plugs look like? They should have been a tan colour.

 

[davidlytle]

I have the same problem in a 900s. It has no power from about 1500 to 2500 or so them wam it kicks in. feels like a 2 stroke dirt bike when not in the power band. not sure if its the O2 sensor, fuel filter...