rpms while on the trailer

[REELSPORT]

I have a 1969 rude 55hp and I was trying to adjust the carbs and I read somewhere here on the forum just take it to the lake and back it in until the lower unit is under water warm it up and adjust it. The weather was so bad here today I didnt want to put it in the water so I did what was suggested above. I warmed it up and adjusted the carbs and then went to wot it took the gas well and ran good but the rpms would only go to about 4200 I know at wot it should be at 5000 but with it being on the trailer would that effect the rpms and that is my question to you guys. thanks in advance for taking time to try to help me.

 

[JB]

Re: rpms while on the trailer

OMC saved your engine for you by partially blocking the throttle in Neutral to prevent you from revving it with no load into thermal runaway and disintegration, Reelsport.<br /><br />WOT with no load on an outboard is very dangerous and has resulted in grenading many engines.<br /><br />Luckily, it did what it is supposed to do.

 

[R.Johnson]

Re: rpms while on the trailer

It should hit 5000 on the trailer with no problem! Infact! if that engine were running right, you should be picking it up with a broom.

 

[DJ]

Re: rpms while on the trailer

if that engine were running right, you should be picking it up with a broom.

Ditto! <br /><br />A two stroke engine will rev quite easily with no load, even if not running right.<br /><br />You really need to water test it.

 

[REELSPORT]

Re: rpms while on the trailer

Maybe I did not make myself clear I had the engine in gear the lower unit was under water the prop was turning I backed the trailer into the boat dock until the lower unit was under water. The motor had a load on, more of a load than if the whole boat was in the water I think and that was my question would the motor trying to push a boat that was stationary cause the motor to not have as many rpms as it would if the boat were floating and taking some of the load off by moving.

 

[jy118lfd]

Re: rpms while on the trailer

Reelsport take her out and run it then post with wot and speed. It might just be ok I feel the same way as you boat not moving it will not rpm as high

 

[Marc J.]

Re: rpms while on the trailer

I had the same experience this week Reelsport. I was trying to get the revs up to 4500-5000 (in gear) to set the timing with a timing light. My 90hp wouldn't get much past 4K tied to the trailer. On the water 5K was no problem, trimmed it up a bit and got 5500rpm. I didn't expect it and can't explain it.

 

[REELSPORT]

Re: rpms while on the trailer

Thanks 73baja<br />I thought there might be something wrong with my<br />motor. I think I understand why you get less rpm<br />at wot tied to a trailer. It is like trying to <br />push a tree over with your car your engine will <br />not rev as much as it would if you were on the <br />open hiway. I had replaced #2 spark plug wire and<br />was trying to see if it would take the gas better and run smoother at wot and it did. The weather is hopefully going to be better tomorrow than it was tody and I am going to take it out in the morning along with my gps to check out the speed and rpms and I will let you know how it does.