2003 Yamaha 130TLRB 2 stroke

H

hudelrob

Recruit
Joined
Jul 15, 2010
Messages
3
I replaced my complete lower unit with a SE405 after market lower unit from

http://www.sterndrive.cc/mm5/merchant.mvc?Screen=CTGY&Store_Code=SE&Category_Code=SE405

After replacing the lower unit I took the boat for a test ride. Starting out at about 3000rpm slowly increasing 200rpm's until I reached full throttle. After a few times around the lake my warning alarm went off. I immediately put the boat in natural then pushed the button so I could increase the RPM to pumped higher volume of water a few sec after that the alarm silenced. I also checked both of my oil reservoir to insure they were full. I then again proceeded down the lake with caution working my way back up to 4600rpm (Full throttle) it seemed to be fine until I turned and the alarm went off. I again immediately went to natural and slightly increased throttle to increase water flow and it silenced the alarm.

Took the boat home and dropped the lower unit and checked the following items

Intakes: No obstruction could be found
Water pump: Removed the top housing to ensure water impeller looked fine and was not just spinning on the drive shaft.
Thermostats: Test both thermostats to ensure they begin to open at 50C.

I have also contacted SEI (who I bought it from) and they suggest that I remove the water pump and compare all the part to my original one.

I am very confused at this point because I did not have any cooling issues prior to replacing the lower unit.

Thoughts /Suggestions?
 
9

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,116
Re: 2003 Yamaha 130TLRB 2 stroke

4600 sounds kind of low for WOT.
Is the gear ratio the same as the old one?
Alarm sounds when you turn?
Is it sucking air some how when turning?
Are the water intakes the same size and position?
 
H

hudelrob

Recruit
Joined
Jul 15, 2010
Messages
3
Re: 2003 Yamaha 130TLRB 2 stroke

Thanks for your replay

I took the water pump assembly apart and swapped out the flat plate and the cup like dish that inserts in to the top of the plastic water pump housing. I really couldn?t see any different between them but SEI suggested that maybe I give it a go.

Took the boat back out and ran it for almost 1.5 2hr and the alarm never went off. Now I am not sure if there was an assembly issue or swapping those part from my original lower unit fixed it.

On question that I do have is what should the normal RPM range be when at full throttle. I currently have 2 props a Stainless 13.25X21 and a aluminum 12.5X21.

The Stainless gives me good top end performance but it is a dog out of the hole when I have full fuel and 3-4 people in the boat. The aluminum one performs well out of the hole but when I trim up its at 5000rpms and gives me a top speed of around 42mph.

I have been told not exceed 5000rpms
 
Y

yamamarinetech40

Petty Officer 1st Class
Joined
Dec 17, 2006
Messages
328
Re: 2003 Yamaha 130TLRB 2 stroke

You were told incorrectly on the RPM's....it's very important that the full throttle rmps not be UNDER 5000 rpm...that is to make clear, you must get 5000 rpm at w.o.t.....you want 5000 to 5500 on this motor...and 5500 is better than 5000....if you go to a dealer and ask to see the yamaha P.I.G.....on each models page at the bottom is a note warning to make sure that the rpm range is followed AND to try to get to the top of that range...it's what the motor likes....may sound odd to you but it's really not if you could see relationships in engine....glad you found the cooling problem and everyone should take note of how you quickly went to idle and used a little throttle to push water thru engine before continuing back to dock...good luck
 
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