R25 Impeller Change

[captstu]

Hi, In several unrelated posts, I noted the engine temperature climbed from 195 to 210 - and sounded the engine alarm when I raised the 4BY2-150 from 3000 to 3500 RPM. Since it was 2 years since the last impeller change, I decided to tacile the dreaded project. With some help and encouragement from several Tuggers, the new impeller is now installed.

Question:

How do I get the belt back on? The engine repair manual talks about a breaker bar and similar impossible to fit tools that would turn the engine clockwise and force the belt on. That just isn't possible without some more cutting on the boat - something I'm reluctant to do. I know I did this step two years ago, but it wasn't hard enough to accomplish for me to write down what I did.

I'm thinking of putting the belt on the engine pulley and as far as I could on the water pump pulley than fastening the belt to the water pump pulley with wire wraps (very small) and just bumping the engine. Tell me this is stupid and what I should do.

Question: Did you reuse the "O" ring? My replacement pump impeller did not come with an "O" ring - I ordered one, but would like to avoid changing the mess out a second time.

One (hopefully) final question: I went to order a spare impeller. The Johnson exact replacement comes with 3 "O" rings and a gasket - I suspect the impeller is used in more than one pump. The "run dry" comes without an "O" ring. It is virtually impossible to reuse the "O" ring since it is very hard to get it back in the groove - the new one I used last time went right in. What do you do? Even though the run dry is more expensive, it is so hard to install, I prefer the added assurance of the more expensive unit. The "O" ring is not a separately available part in the Yanmar parts catalog - so I don't have an obvious size to order separately. Do you have a separate source for the "O" ring? Do you reuse it? Or, do you just order Johnson parts.

Thanks! /Stu

 

[aculverwell]

On my prior boat (R27) with a 4BY2-180-- which I imagine is relatively similar to your 4BY2-150-- I was able to get the belt back on after an impeller change by slipping it part way on the water pump pulley and using a socket wrench to rotate the engine pulley so that the belt "climbed" back into the groove. It has been a while since I did this, but I don't recall it being especially hard to do (other than the fact that my head and shoulders were painfully squeezed into the small hole in the cabin step). I would definitely not turn on the engine to "bump" it.

Not sure about the gaskets... I always ordered replacement parts from Richard @ Ranger Tugs and used whatever came in the box.

 

[Brian B]

I have the same engine in the 25SC, I believe I have more room to access the front of the engine. I change my impeller yearly and now I can do it in less than an hour. I just changed it 10 days ago and I use the Johnson brand impeller that comes with an O Ring. I put a little Vaseline in the ring groove to hold it in place while the pump is reinstalled. I put the belt on the pump pulley and then on the crankshaft pulley as far as it will go by hand, then turn the crankshaft with a 22mm socket clockwise. The belt will stretch onto the crank pulley. Be sure all the grooves in the belt are engaged on the pulley properly, sometimes I have to repeat this step to get it aligned properly. I use a belt stretch tool to remove the belt but find it is not necessary to use one for installing.
The part # for the Johnson pump is 09-1028BT-1, F7 series.

 

[captstu]

Brian,

I can get the socket on, but I'm not nearly strong enough to turn the engine. How large a breaker bar do you use on the socket? I use the regular ratchet driver and a 1' long piece of pipe - because of the very restricted space, I just can't budge the engine. Oh well, I suppose it is wheaties time. Thankis