DHadley, could you look at the pics of my motor height??

[farginicehole]

Re: DHadley, could you look at the pics of my motor height??

(subscribing to thread)

 

[Dhadley]

Re: DHadley, could you look at the pics of my motor height??

To lose 1200 rpm after a rebuild is reason for concern. Something was changed during the rebuild. Did they use the same block? Same carbs? same jets? Did they alter the jetting in any way? <br /><br />It sure looks like its running rich but that could be from lack of rpm. What has the rebuilder said about the rpm loss?<br /><br />We should verify the rpm with a shop tach or a good known tach. Running a seperate wire to the yellow/grey post is OK.

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

The builder said there is nothing wrong with the motor, he says the problem is with my boat... Which is not true....<br /><br />I verified the head plugs matched my model number so the block appears to be the same, basically what he did was removed the power head I took the boat home, and when completed I took the boat back and he reinstalled the power head.. Thats how I know the boat is OK..<br /><br />He did replace one of the heads, and #3 cylinder is .020 over while he left the other 3 std bore.<br /><br />Other than that I am unaware of anything else changing...<br /><br />You walked me thru a ton of steps on a previoue thread "engine swap" I was going to repower my boat with a 150hp Johnny and you wanted to look into why my 140hp motor wasnt doing its job...<br /><br />So we have covered pretty much all of the basics I am trully stumped.... carbs, fuel pump, compression, horizontal throttle position, timing, exhaust leak, prop selection, ignition, etc ALL checks out OK, heck I have pretty much replaced all of it with new parts.....<br /><br />I did leave the original tach wire under my dash, maybe I could hook up a different tach and verify both at the same time.....<br /><br />Now I just need to find one...<br /><br />But I can tell by the sound it is way off....<br /><br />OK 1 last thing.. I installed my 13 1/4 x 17 Hustler prop, and it still only pulls 4800 RPM @ 35-36 MPH.. NO RPM change between props.... Its like there is a govenor on it.....

 

[Dhadley]

Re: DHadley, could you look at the pics of my motor height??

Thats a clue. Lets get the tach verified. It may not be at 6000 but it may be more than 4800 too.

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

Will a standard tach work, or does it have to be for a 2 stroke motor?????

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

I havent had time to verify the tach yet, But I did do a compression test again since replacing the head gaskets... #1 105, #3 100, #2 110, & #4 105..... That is interesting, last time I did a compression test is ranged between 105 - 115.. Maybe I have a battery going low....<br /><br />That seems low for a motor that has less than 40 hours on it..<br /><br />I also just de-carboned it as well.... Boy it smoked alot..... Should I change the plugs after I decarbon??

 

[Solittle]

Re: DHadley, could you look at the pics of my motor height??

YOur compression is just fine.

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

Thats good to hear...... about the compression..<br /><br />I have another question... I marked my SST 13x19 prop prior to my last test run.. I just removed it and the marks no longer line up, they are off maybe a 1/4 of an inch..<br /><br />Is this common due to torque, or is this a sign I am getting ready to spin the hub????

 

[Tacklewasher]

Re: DHadley, could you look at the pics of my motor height??

Originally posted by ddbyrd3:<br /> Thats good to hear...... about the compression..<br /><br />I have another question... I marked my SST 13x19 prop prior to my last test run.. I just removed it and the marks no longer line up, they are off maybe a 1/4 of an inch..<br /><br />Is this common due to torque, or is this a sign I am getting ready to spin the hub????

No, you've spun the hub. You need to fix that before you play with anything else. You can't tell if it just moved that 1/4 inch or if it was raotating a whole lot slower and happened to end up off by the 1/4 inch.<br /><br />Just did this myself last weekend. Prop is repaired and I'm going back out today.

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

Thats what I figured.... Off to the prop shop...

 

[joblo33]

Re: DHadley, could you look at the pics of my motor height??

Maybe you were spinning 6k with the spun hub?

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

DHadley, I cant seem to locate a tach in order to verify the one I have in my boat... Will an inductive timing light work that displays RPM on it??? <br /><br />Will a standard automotive tach work or does it have to be marine cabable (2 stroke)???

 

[Dhadley]

Re: DHadley, could you look at the pics of my motor height??

The timing light will work but if it reads automotive tach output it'll read twice what the rpms are. I've seen some of those tachs on timing lights not read right when trying to do a 2 stroke. The best bet would be to have a dealer check it aginst a shop tach.

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

Will do...... <br /><br />I am even more curious about my RPM reading now since I found that my prop hub has been spun.. I looked at the rear of the prop and I can see rubber peices that have come apart...<br /><br />I am suprised the RPM's didnt go allot higher on my test run the other day unless the prop just started to go...<br /><br />I have been looking at Stiletto props, do you recommend 3 blade or 4. I do mostly skiing, wake boarding, etc...

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

All shops around my area are 3 weeks out for service........ So I guess I will have to resort to plan "B", I just wish I know what plan "B" was....<br /><br />DHadley, I spun the hub on the prop shown above... Would it be worth getting that prop re-pitched, say to an 18, or should I just have the hub fixed and leave as is a 13 x 19???

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

Bump.

 

[Dhadley]

Re: DHadley, could you look at the pics of my motor height??

We need to stay with the knowns while we figure out what happened. If the hub was actually spun I'd think the r's would be much higher. basically when a hub spins the load is released and the r's go outta sight, or can if youre not careful. I have never seen a spun hub limit rpm. Youre prop shop can check it to see if its spun. They have a way to jig it up and put torque on it. If its within spec then its OK.<br /><br />I think we went over this before but maybe it was someone else. have a dealer put the motor on a propshaft dyno. If it comes up to the proper spec then the motor's OK. We can look elsewhere. I bet it wont. Theres too many things pointing to the fact the motor or tach wont go past that rpm.<br /><br />The clue is that the motor or tach only goes to 4800. Gouing from a 19 to a 17 should do something. A spun hub should do something. Next time you run the motor try trimming up until the motor vents. Once you hear the motor spin free if the tach is still at 4800 then we know its the tach.<br /><br />Yes, a decarb cant hurt.

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

Thanks D, I marked my prop with a paint marker, took it out for a test run, came home and pulled the prop off and the marks no longer lined up, the hub spun a 1/4 turn. Also when I turned the prop over, I can see peices of rubber inside the hub area.<br /><br />I will be picking up a 2 stroke tach tonight and I will be launching tomorrow to verify the "R's".<br /><br />And I agree, if the prop hub was completely gone I would expect the R's to go thru the roof, so obviously it isnt totally gone, but I will tell ya, with my SST 19 pitch prop, my hole shot is TERRIBLE when compared to my 17 pitch composite prop...

 

[Dhadley]

Re: DHadley, could you look at the pics of my motor height??

One thing that kinda bothers me about the set up is that -- looking at the pics -- things seem to be off. The idle stop screw is in quite a ways, the timing stop is retarded quite a ways and the cam follower is adjusted way to the end. Generally speaking, these things should be about in the middle. There are specific locations for everything but they are usually somewhere around halfway. They might be right but it sure looks odd.<br /><br />Now heres a silly question -- I know you said the carb linkage opens all the way. BUT do BOTH carb butterflies open to horizontal? What I'm getting at is that we're sure the top butterfly is going flat but is the bottom one? Make sure they (either one) doesnt go past flat.

 

[ddbyrd3]

Re: DHadley, could you look at the pics of my motor height??

No they are identical..... I even installed the new plastic clips the linkage locks into to be sure they were the same.<br /><br />As far as the linkage goes, The builder did the synk & link back in 01 when he reinstalled the power head. Now accoring to my book, the cam follower that rest on the nylon throttle roller is on the proper mark, As far as everything else, I cant really say. It appears to be doing everything the book specifies. <br /><br />At idle the a hush muffler (simulates in water back pressure) the timing it a 5*. The manual specifies 4 to 6, so that appears ok. And I re-verified WOT timing at 28* at the 4800 - 5000 RPM on the water last week. (that was fun)<br /><br />So everything seems to be doing what it is suppose to...<br /><br />I will post a close up picture of the linkage setup, maybe that will revile something....