Hi Guys,

The 16 valve is running well on the whole and part of me thinks if it ain't broke don't fix it'. But I get the impression the engine could do with tuning up, mosatly because the idle is a bit lumpy (is this normal?) but otherwise it pulls very well. The bike has been serviced (fluids, new plugs etc) and I changed the air filter but otherwise the history is patchy and there are no records of things like valve clearance checks/new shims etc. I have the old plugs and they look great - a nice even light brown. I'm a bit lost where to start or whether to start at all so advice would be appreciated. I'd like the bike to be performing at its best but don't really want to create work for myself.

Finally, on the throttle bodies there are 4 short open brass tubes with rubber caps on them, except I have only 3 caps. I suppose it does something, could it, alone be responsible for the lumpy idle?

Thanks in advance
Dave

MT350Explorer wrote:Hi Guys,

Finally, on the throttle bodies there are 4 short open brass tubes with rubber caps on them, except I have only 3 caps. I suppose it does something, could it, alone be responsible for the lumpy idle?

Thanks in advance
Dave

On this brass stub at cylinder #1 it should be a hose connected to the FPR, caps on the rest.
If the stub is open you would shure get a crappy idle.

Best tune up you could do is to synchronising the air bypass screws at the throttle bodies.
And test for intake leak if you still got a crappy idle after this have been done.

Inge K.

Thanks Inge,

See picture, it's cylinder No. 2 with no cap. There is a hose connected
to the stub on 1, I was wrong in assuming it also had a cap.



Is there an idiots guide to synchronising the air bypass screws at the throttle bodies you could point me to please?

Thanks
Dave

Get a cap for that stub, and you would think that you got a new bike, as a temporary solution you could
get a thin walled hose of the correct diameter and kink it 180 degree to close it, secure the kink with
some steel wire.

About synchronising the throttle bodies bypass, it`s heaps of info about this on the web, and also some
on this forum.

One forum that explain it rather good is Motobrick but it`s based on a Twin Max that only connects to two cylinders at the time...

You better get some equipment that is connected to all cylinders, one that could be recommended is
Carbtune or something similar, rather that a one thats relying on manometers,
cause it`s rather seldom each manometer shows exactly the same value at a specific vakum.

Inge K.

Thanks Inge, will cap it tomorrow.

I now understand what you mean synchronising the throttle bodies with all the gauges and tubes etc so the same amount of air goes in to each cylinder.

Much appreciated

Dave

Here's a top tip. When I had a look this morning only one of the little rubber caps was any good. In the photo is the second cap (right), melted and split it can't have been sealing properly. If you are ever in the same predicament I can recommend using the rubber caps from the end of bungees (left)! These ones at least fitted like a glove and should be a good temporary fix.