Yammy 115 idles but wont rev out....

[ozscott]

Hi all - 94 Yammy 115 V4. Been a fantastic motor. I had had crap in the float bowls before causing intermittent stalling at idle, but apart from that its picked up its heels and always run like a champ.

Today took her out for the first time in months. But it had a service just before the last time out with new plugs. It started, but not as cleanly as usual. It idled fine, but anything above 1100rpm and she started to die...sounded like it was flooding...tried to run her out and re-primed her with fuel from the second tank. I run a good quality water trap. I checked and the choke lever to the butterflies were disengaging the butterflies properly.

Any ideas?

Cheers

[ozscott]

...I had the float bowls cleaned out when it had crap in and its always idled and revved out like a bought one...

[Chimo]

Hi OS


Yours is the carby motor I think?

Sounds a little like the issue I had with both my Evinrude 115s but 10 hrs apart.

They would run ok at idle or low revs but run them up and they died.
Wait a while and start and same thing over again.

Turned out it was the fuel pump. The spring on one side of the diaphram had let go. As I said same issue on both motors 10 hrs apart.

The second time we found the problem very quickly.

Maybe worth checking on yours?

Cheers
Chimo
(The Vag Team)

[Kleyny]

start with the basics.
check the plugs even if they are new. if you have old plugs throw them in.
check the fuel. try running the motor from a small container not from your tanks. (drain your carbs before you restart)
if it still does not rev try giving the carbs another good flush/clean.

Do all the plugs look the same? ( all simillar in wetness/ dryness)
neil

[Kleyny]

Hi OS


Yours is the carby motor I think?

Sounds a little like the issue I had with both my Evinrude 115s but 10 hrs apart.

They would run ok at idle or low revs but run them up and they died.
Wait a while and start and same thing over again.

Turned out it was the fuel pump. The spring on one side of the diaphram had let go. As I said same issue on both motors 10 hrs apart.

The second time we found the problem very quickly.

Maybe worth checking on yours?

Cheers
Chimo
(The Vag Team)

another good thing to check

[backlash08]

idles and wont rev, generally fuel flow, blockage somewhere between tanks and cylinder
chhers
Craig

[ozscott]

Thanks fellas - will do some checks.

Cheers again

[Hagar]

Ozscott

You can quickly eliminate the fuel pump by having some one keep squeezing the bulb in the fuel line while you try to increase revs . Make sure it pumps up hard . About the first third increase in revs is purely timing advance on a two stroke anyway . Open the throttle with the engine stopped and watch the linkages and you will see there is no butterfly opening initially - just advance mechanism . Make sure nothing has happened to the linkage to the advance mechanism . If OK then look further .

Chris

[ellykan]

Hi mate,

i had a 95 115 yammy about three years ago. it wouldnt trottle up due to faulty overheating protection sensors. since heard that this is a common problem with them. there are two black button like sensors on each head with two wires runnin from both. if block doesnt feel obviously hot try disconecting the wires from eac one at a time to find the faulty one. they are great at insuring damage buy limiting revs if motor is overheating but they can play up from time to time

ellykan

[ozscott]

Thanks Hagar - i have checked linkage operation and it all looks good. I will try to prime up the bulb whilst running.

Ellykan - thanks mate - but with mine there is an alarm that comes on as the revs cut back - I know that from having a poppet problem a little while ago (its in the user manual also), and Im getting no warning buzzer.

Cheers again

[mowerman]

I had the same problem with a 90 Yamaha.

But the bloody thing would also take 6 gos to start as well.

Tracked it back to....fuel.

Water seperator filter, looks like a car oil filter?

Run a new film of oil around the O ring,,bothsides and screw back on.
Hasnt missed a beat in 2 months since I did that.

Sucking air is not good...


Rod

[ozscott]

Gday all - turned out to be the timing advance unit under the flywheel - no advance just fuel It was seized (lack of use!) and needed a clean up...going like a etec now (:))

Cheers