Lack of power in 4th

[owent2005]

Morning all,

Ive noticed that occasionally when in fourth, (sometimes when first setting off, sometimes after driving for a while) it looses its umph. Its happened on hills which I understand but its also happened on very slight inclines slowing right down to 30.

Is this a norm or should i investigate further?

Any thoughts would be appreciated.

 

[StefansBus]

30 MPH is a bit slow for fourth, especially on any kind of incline. The stock earlybay transmission has quite the gap between 3rd and 4th. Mine accelerates quite well (considering it's got only 47 BHP) in first through third but then in fourth there is quite a drop in acceleration. One way of mitigating is to really rev the third quite high 40 to 45 MPH or so) before shifting up. Even then, anything more than a slight incline it has trouble maintaining cruising speed, which for me is 55 to 60 MPHH most of the time. As a rule, you need to downshift at the latest when you can't maintain a sensible RPM (for cooling) at full throttle.

I assume your engine is set up and tuned correctly? Carb, timing, spark plugs etc? What puzzles me is that you report it only happens occasionally. That doesn't seem right.

Stefan

 

[ozziedog]

There`s a lot of things you could check and most are part of regular maintenance. It does sound like the valve clearances could be a little tight or perhaps your fuel pump isn`t giving its all any more, but if it`s just very ocaisionally i`d be checking points gap and condensor, could also be float height or an ocaisional fuel blockage.

Ozziedog,,,,,,,,,,,,,,it`ll be something simple (I hope)

 

[Guest]

A feww things you could do to upgrade, your stock carb, there's a good tutorial in VoW how to change the jets etc. You could get an electric fuel pump, electronic ignition etc.

Have you had/done a compression test recently? check the spark plugs? HT leads? there are so many things that could lead to a loss of power.

 

[SiDev]

Is it only in 4th? Post up a pic of your gearbox and another of your engine, it's possible you have a mis-matched box and motor (previous owner could have popped a bigger motor in and a later 5 or 6-rib gearbox, then put a stock motor back on to sell). Pics will help diagnose.

 

[owent2005]

Cheers guys for the pointers, its a recently fitted reconditioned engine that is due into the garage for a flush so i'll mention it then. As I'm new to the scene most of topics I put on are to find out if things are the norm or not!