can't get max rpm on suz 140

[nuffy]

Hi 2 all, this is my first post.Iam looking for help with my haines19c,140 2 stroke suz.I am struggling to get past 5000rpm at full throttle.I have just purchased a s/s prop from solas,17"pitch recommended by steve.The motor was mounted by jon at neptune<rumoured to b a suzuki expert but since moved on>so i am confident this is not the problem.Motor has been serviced and carbys removed and cleaned.Jon has told me i should be getting 5600rpm and it should even go to 6000rpm if limiter allows.I dont think iam getting good fuel economy by not getting max revs from the motor.Every now and then it has trouble getting past 4500rpm and then all of a sudden kicks in to 5000rpm without touching the throttle,like its binding up or chocking but this is very spiratic.Could it have anything to do with thrust washer?Any suggestions would be greatly appreciated.Tony.

[blaze]

would think that the 17" prop should do the job, dont know much about the 2 stroke suzi's. What happens when trimming the motor. Where is the cav plate sitting in relation to the bottom of the hull. Are you gettin max throttle position on the carbs when the controller is in WOT position.
Fuel filter ?.
May even be a timing issue.
Pay to have it checked as this is the sort of problem that can cause a motor to run lean and pop a piston
more question than help
cheers
blaze

[Spaniard_King]

Tony,

why are you asking about the thrust washer??? is your prop or thrust washer binding on the gearbox/bearing carrier??

You will not get the RPM if the engine is too low in the water either

Garry

[nuffy]

Thanks Blaze and Garry 4 your reply.Max throttle is ok and cav plate is in line with bottom of hull.When i get her up out the hole which is no problem i trim the motor up quite a fair way until she starts to rev higher and then drop it down a touch.Motor runs sweet with no missing.Has 240hrs on the clock with good as new compresion and new plugs.the reason i asked about thrush washer was steve could not supply one with prop so the old one was used and to me doesnt seem to fit snug on the shaft it is tappered and there is quite a bit of sideways movement.Not sure if this is normal or not.When i push the prop in towards gearbox it goes in about a 1/4"and springs back, is this standard as well?THanks again for your feedback..Tony.

[blaze]

most prop shafts have a taper where they come out of the gearbox and there should be a corrisponding taper on the washer. Depending on the type of prop the outa side of the washer should locate into the prop housing. have you replace the prop with a newer flo torque type prop from an existing rubber bush type huh type (these had flat washers)

[Spaniard_King]

When i push the prop in towards gearbox it goes in about a 1/4"and springs back, is this standard as well?THanks again for your feedback..Tony.

NO its not standard. Remove the prop and see what it has been rubbing on, you may have done damage :(

I think you nbeed to get the right thrust washer and solve all ya problems

Garry

[nuffy]

Thanks again guys i will take the prop off in the morning and have a look for wear.Yes Blaze the old prop was a rubber bush type.But if this washer is not the correct one would it still cause the lack of rpm,as well as cavitation when turning?tony..