motor mounts

[trbig]

the XS11 has sometimes been described as having a 'hinge' in the frame, lessening the quality of handling due to to-soft mounts.

That "Hinge" is fixed... or at least helped a bit... with a fork brace for the weak forks on these bikes that flex while cornering. A motor is basically mounted to three areas on the lower half of the frame. There's nothing tying it to the upper rails in any way. It's really just a hunk of aluminum affixed to the bottom side of a cradle.

Without affixing this engine somehow to the complete frame.. upper and lower... with multiple attaching points to ridgidly tie several points of the frame together and making it stouter, simply mounting a few points solid to the bottom side of a "Box" isn't going to make something handle better. Not percievably anyway.

I wouldn't argue that there may be a H/P or two more getting to the ground without any flex in these bushings.. but again.. I don't think any of us here would notice that subtle of a change.


Tod

[DELL82]

mxmikie. Are the urethane rubber durometer (hardness) about the same as the originals? Do you have the mounting hole dimensions in the engine?

I wonder if this can be used on the XJ1100 Maxims. My mounts are oval and hard so I get unusual vibrations in the bars and was wondering if I can replace the three mount pairs and weather I can do that without taking the engine out of the frame. Anyone ever replaced the original mounts in the XJ1100's, and with what?
Thanks for any replies
Dell82

[mxmikie]

mxmikie. Are the urethane rubber durometer (hardness) about the same as the originals? Do you have the mounting hole dimensions in the engine?

I wonder if this can be used on the XJ1100 Maxims. My mounts are oval and hard so I get unusual vibrations in the bars and was wondering if I can replace the three mount pairs and weather I can do that without taking the engine out of the frame. Anyone ever replaced the original mounts in the XJ1100's, and with what?
Thanks for any replies
Dell82

they are harder i dont have the hole size if you can send me one of your mounts(all the same ???) i prolly can fit you with some inserts

[trbig]

The mounts and engine blocks are all the same for the XJ/XS. The problem with trying to install them, is that you'd have to be able to jack the motor up high enough to get them out. You may be able to do that, but you'd have to drop the exhaust and at least loosen the back one while you take the front ones out. I could be wrong, but I'm thinking you'll probably have to take off the valve cover also to get enough room. I've been wrong plenty before though! lol.

Tod

[mxmikie]

The mounts and engine blocks are all the same for the XJ/XS. The problem with trying to install them, is that you'd have to be able to jack the motor up high enough to get them out. You may be able to do that, but you'd have to drop the exhaust and at least loosen the back one while you take the front ones out. I could be wrong, but I'm thinking you'll probably have to take off the valve cover also to get enough room. I've been wrong plenty before though! lol.

Tod

you can jack the front up to change the 4 front ones with no problem i unbolted the drive shaft to get room for the rear

[DELL82]

I guess my next step is to find out what the original durometer was for the mounts. They are fluted to get a softer mount so I am guessing about 70, like a car tire rubber. Modern cast able urethane's can be had in many durometer's from 10 to 80. If we knew what was really needed then I could get the proper hardness and cast solid, not fluted, mounts using an RTV mold. Any thoughts in reference to this project?
Dell82

[DiverRay]

The original mount was made to ease the vibration at cruise RPM. I would guess that something that would take the 3K to 4.5K range out is what we need. I just don't know what that is in your scale....

[mxmikie]

I guess my next step is to find out what the original durometer was for the mounts. They are fluted to get a softer mount so I am guessing about 70, like a car tire rubber. Modern cast able urethane's can be had in many durometer's from 10 to 80. If we knew what was really needed then I could get the proper hardness and cast solid, not fluted, mounts using an RTV mold. Any thoughts in reference to this project?
Dell82

the 2035 poly inserts are 70 hardness

[DELL82]

The solid, non fluted 70 Duro mounts will be more rigid than the originals. 70 Duro is very close to cager tires hardness. I believe the original mounts were vulcanized ones which lead me to believe they were probably about 70 Duro, what say you'all. Now how to figure what Duro is needed to have solid, non fluted, mounts that will take out the 3~4 k vibration.
Dell82

[aussixs11G]

urathane mounts.....

what an elegant solution..........
I went the down road of turned aluminum mounts (my spellcheck insists that aluminium is incorrect here yet is correct here in Aus.) these I siliconed into place - all in the interests of handling and removing that "hinge" referred to above.

My engine is balanced - I reckon vibes originate from the drive chain (tailshaft/wheels)

[mxmikie]

you could flute these with a carbide bit in a die grinder or dremmel

[mxmikie]

just started riding the bike seems like it is tighter/firmer i like the feel better in the turns i did not notice the vibe in a 400 mile trip to the store

[mxmikie]

http://cgi.ebay.com/ebaymotors/NOS-Y...d=p3911.c0.m14

[yamahansolo]

if you go up to links and then to the dutch page they have a post for using vmax solid aluminum mounts.

[mxmikie]

i am going to place an order for a bunch of urethane next month .... anybody want/need a set or two of these ????? i have been busy making all kinds of mounts http://www.teamswift.net/viewtopic.php?f=32&t=42065