it dont wanna rev???

[rnli rich]

hi guys, just found your website- awesome guys, good work , totally lost 4 hours reading various threads, anyhow back to my question,
ive just brought-what i hope is a bargain,a lovely 7.5 1980 ac lightening for 200 english pounds, ive been running it in my bucket (a very large one!!) all is going well just one thing, she doesnt seem to want to rev, she runs fine, starts well (just a touch of choke seems to get the old girl going)
the only thing is she doesnt seem to want rev very hard, ive had other engines (yammy and a merc) and they both scream like a scoulded cat,
so guys and girls, what could the problem be-im thinking dirty carbs, so please please guys,tell me this is an easily recified problem.
one more thing, on the engine it has next to the choke,another lever type thing which you can point to either rich or lean-whats this??
any help you can send my way will be much appreciated

 

[Vic.S]

Re: it dont wanna rev???

Starting with the last thing first because it is the easiest to answer. The control next to the choke is the slow running mixture adjustment. When it's warmed up adjust it to the best setting, pull the knob off and refit it to the mid point on its scale . You should also find a slot in the end of the needle for a screwdriver once you have pulled the knob off.

As for the failure to rev it could be that the carb needs cleaning, but before tearing it apart check that the throttle valve is opening fully when it should be. It is opened by a roller on a lever that follows the cam on the magneto base plate.

Plugs are OK I suppose (no points to worry about)

You'll find the engine parts diagrams at "http://epc.brp.com/default.aspx?brands=ej&lang=e" useful. (sorry you will have to copy and paste the link as direct links are not allowed on here)

Folks on here will suggest you buy a workshop manual, alien though that is to the British way of doing things.

In the UK Wills Marine have been found to be good for spares "www.willsmarine.co.uk"

 

[iwombat]

Re: it dont wanna rev???

You'll also want to avoid reving it high in a bucket. You can ruin your motor that way. You either need a properly baffled test tank, or a real body of water to test the upper end of the RPM range.