2015 New Design SGX Twin " Big Engines"

[Tom Foley]

Installed Done for prather silcone tube" large" , servos. switches, antennas and RXs next I will paint yellow on the cowl and I still wait that Andy will mail the bolts& nuts for my boom main

Just a thought , on my old 90 single I added a third engine mount bolt and grommet in the tub and it really takes the see - saw rocking out of the mounting system and weighs next to nothing . Grommets last a lot longer that way with those heavy big blocks .

 

[dwilfong]

Made my own mounts for my SGX.

Solid as a rock but still isolate the vibration from the tub.

No more driving the dog in to the strut with a 1/4 gap at the drive dog.

Unbreakable with the SS mounting hardware.

 

[David Bryant]

Made my own mounts for my SGX.

Solid as a rock but still isolate the vibration from the tub.

No more driving the dog in to the strut with a 1/4 gap at the drive dog.

Unbreakable with the SS mounting hardware.

interesting. I assume you're using LockTite (Blue or Red) on bolt threads where they tap into aluminum mount?

 

[Gary Staus]

i added center mount bolts also,my walt barney tanks hold 30.1oz. each

 

[dwilfong]

The Lock Tite did not hold for long so I put a small jam nut on the end and red Lock Tite.

Drilling a hole and inserting a set screw would work also. But I got lazy. LOL

 

[David Bryant]

The Lock Tite did not hold for long so I put a small jam nut on the end and red Lock Tite.

Drilling a hole and inserting a set screw would work also.

I'm amazed that the popular nylon bolt fastening system used today does'nt vibrate apart, or even shear, with the torque and RPM's generated by the current power-plants.

 

[steve wood]

the solid mount system is what fails. I have had bolts come out,wood rails epoxied in come out ,you name it. nothing with rubber mounts

 

[rbarile]

Had same problem on my 90 SG, and replaced nylon to steel bolts. I found the ridged steel bolts transferred

more vibration to hull but as said it is more stable ?? Have you run the engine up yet??

Just got my 80 twin from any b. Have to make a decision on the change.

Rich B

 

[Andy Brown]

Had same problem on my 90 SG, and replaced nylon to steel bolts. I found the ridged steel bolts transferred

more vibration to hull but as said it is more stable ?? Have you run the engine up yet??

Just got my 80 twin from any b. Have to make a decision on the change.

Rich B

We have built a huge amount of boats using the Nylons bolts. They work!

To reduce engine flex we now make the motor plates reach the side of the hull as David W. did. Mount now has just the right amount of give.

Richie, the only problem we have ever had with the nylon bolts in the Twin 67/80 is that they will sometime vibrate loose. Most often, just getting them tightened well cures the issue. If not, then there is excessive engine vibration.

A new delrin 90 mount that reaches the sides is pictured below.

 

[Buckshot]

I ran the piss out of my single .45, 67, 1.01 and twin .80 SGX's and never had motor mount issues. The nylon screws work absolutely fine!

AB,

The new system looks good!

 

[Andy Brown]

The Lock Tite did not hold for long so I put a small jam nut on the end and red Lock Tite.

Drilling a hole and inserting a set screw would work also.

I'm amazed that the popular nylon bolt fastening system used today does'nt vibrate apart, or even shear, with the torque and RPM's generated by the current power-plants.

David, We have been using the nylon bolts since the late 80's begining with the later Mongoose hulls to the current date. We have built many boats with them. If they were having any issues we would have changed them by now.

We are begining to use larger grommets for the 90+ engines because they sometimes wear fast. But have really only seen that problem in the Twin OPS 90 hull.

 

[dwilfong]

I made those mounts gust like you told me to.

Just added the ss bolts for S&G.

What the hay thy don't add that much weight.

The boat ain't no slower with them.....LOL

I go over board most of the time.

 

[David Bryant]

The Lock Tite did not hold for long so I put a small jam nut on the end and red Lock Tite.

Drilling a hole and inserting a set screw would work also.

I'm amazed that the popular nylon bolt fastening system used today does'nt vibrate apart, or even shear, with the torque and RPM's generated by the current power-plants.

David, We have been using the nylon bolts since the late 80's begining with the later Mongoose hulls to the current date. We have built many boats with them. If they were having any issues we would have changed them by now.

We are begining to use larger grommets for the 90+ engines because they sometimes wear fast. But have really only seen that problem in the Twin OPS 90 hull.

thanks. Yeah, I have'nt had the chance to actually experiment with this system yet, I will soon.

 

[Chris Wood]

you want vibrations and shakes go back to the old days of solid shafts and hard maple motor mounts..

you could glue. screw, bolt , epoxy lol i didn't matter they still busted loose

that was also back when you used screws to hold the radio box lids down.. there are a FEW that remember those days. lol

i know i do.. what a pain.

 

[henry velasco]

Use sealant type silicon on the nylon bolts and they will not vibrate lose

 

[David Bryant]

there are a FEW that remember those days.

i know i do..

yeah, I do too

 

[Gary Staus]

another one,

 

[Gary Staus]

sorry tried posting a pic. didnt work

 

[ALLAN YUEN]

sorry tried posting a pic. didnt work

Send picture to email: [email protected] I will put pictures for you on IW thanks

 

[Gary Staus]