M750 Scrambler Project

[koko64]

A question guys. In your experience how high on the rear heim joints can you go (threads showing) before running into clearance issues with the bell crank linkage? I have always followed the thread rule but I'm talking about the amount of thread showing to measure ride height. I generally haven't exceeded 10mm higher at the heim joint but a mate has run nearly 20mm which has got to be pushing it. What are your calculations on the ratio of heim joint adjustment to ride height at the axel? I make it at 2.5 to 1. Is there a difference to this ratio between steel and alloy swing arms?
Another question, do you dirt guys find a front fairing distracting or an impediment to vision of the ground immediately in front of the bike? I'm thinking that at 5'8" I need an unobscured view of potential potholes ruts etc on rougher tracks/fire roads .

[Howie]

Good question about the heim joints.  I know people have used longer joints successfully.  Maybe you could figure it out without the shock in place?  Dunno.  As far as the fairing goes, no problem for this inseam challenged person.

[Speeddog]

Steel and alloy arms have same pivot point dimensions AFAIK.

I'd say run without the fairing.
If you fold the front, the bike'll fall right on it and squash it.
And you do need a clear view for slow uphill riding in rocks.

I just fitted a set of KTM official handguards to a 690 Duke, they were very nice pieces.
Good to have something for protection from bushes and saplings, and helps minimize control damage in lowsides.

Rule of thumb is 1.5x diameter for heim joint engagement of the mating piece.
IIRC, Axle/Rod ratio is ~ 2.5-3:1 but it's been a long time since I fiddled with them.

I think your *real* limit on heim joint position/shock length/etc is having the top run of the chain start sawing the rub strips up in short order.

The period-correct Ohlins can be made longer-travel with the new seal head.
I set mine up to just have the rocker barely clear the seat/tank support bracket.

[koko64]

For the purpose of simplicity, good airflow to the rear cylinder, easy tuning, easy maintenance and easy roadside trouble shooting, I elected to fit K&N pod filters with outer filter skins and a seperate battery carrier and platform for ignition components. This comprised of the rear section of a spare oem battery box/airbox assembly. The use of a spare Shorai LFX14 coming in at 750gm means no need for extra bracing and the stock location for the coils and ignition boxes is handy. Shorai Jr easily turns the bike over with stock compression.
I am happy with the close to stock jetting from the Factory Pro kit (edit: jetting was stock) already installed and dont want to go big on the jetting with hi flowing airbox mods. Pods will require some jetting changes and larger pods even more so, with that in mind I'm trying some smaller cone shaped pods I picked used and some "Filterskins" which are similar to K&N outerwear bags but are of a medium which requires dirt bike filter oil to be effective. The skins are white and are coloured blue by the Ipone brand filter oil. Edit: The skins are now K&N filter oil pink. Between the oiled K&N elements and oiled filter skins there should be enough restriction to not require any radical rejetting. Probably doesn't flow air as well as a stock airbox, so I'll be doing plug chops to see. Never thought I'd see the day when I wanted an intake that did not flow more air.

The small Shorai battery allows room in the battery box for spare ignition units, call me paranoid.

Since the carbs have the oil heater kit, I'll try to help it work effectively by covering the oil cooler in cold weather and wrapping the manifolds with exhaust wrap.

[koko64]

20180912_185701 by Tony Kokonis, on Flickr

[koko64]

20180912_185713 by Tony Kokonis, on Flickr

[koko64]

20180912_185834 by Tony Kokonis, on Flickr


Showing the blue stained filter skins, comparison between the high flowing K&N barrel filters and outer covers Vs the smaller K&N pods with filterskins infused with tacky filter oil. Edit: Washed the filterskins clean and reoiled them with K&N filter oil to be compatible with the filter oil in the K&N pods underneath. This will avoid the chance of incompatible oil clagging the pods.
Plenty of room for ignition spares each side of where the little LFX14 Shorai will fit.
The cleaner and less cluttered set up will allow for more hand room since the extra plumbing of the oil heater kit to the float bowls really does reduce easy access.

Also decided to remove the bikini fairing as per Speeddog's advice as I'll go for a minimalist approach.

[GK]

You’ve been quite busy Bro!

Keep the pics coming.

[koko64]

20180913_134947 by Tony Kokonis, on Flickr


Pirelli MT60 RS  160/60/17

[koko64]

20180913_182119 by Tony Kokonis, on Flickr

[koko64]

20180913_223957 by Tony Kokonis, on Flickr

Despite all the hours of work, it looks incredibly stock. The lean angle on the side stand gives away the extra ride height giving plenty of clearance for dirt roads.

[koko64]

20180913_224210 by Tony Kokonis, on Flickr


Modified Sargent seat with Airhawk pad for the GLW.
The DP mirrors are too fancy for this bikes purpose.

[koko64]

Dirtbike indicators (nice and rubbery so she cant kick them off when climbing aboard), raised ride height an even 30mm front and back, stock dash, simplified intake and battery box with storage of spare ignition units next to the 750gm Shorai battery. Open area under tank for better airflow to the rear cylinder when riding trails on hot days. Manifolds wrapped in exhaust insulation Covered oil cooler and the oil heating kit turned on for cold days.

To Do: Suspension testing and tuning, settle on MX bars and fit Barkbuster "Storm" guards, test state of tune, modify a generic bash plate, fit Remus pipes, fit lower passenger pegs.

Will test ride tomorrow, first by myself and then with the pillion in a million.

[amcjen]

Amazing thread, I love seeing scrambler mods to the Monster line.  I’m thinking of doing one to a 2013 Monster 696, as it sustained some damage to the front end after an accident. Figure, part it out or mod it to a scrambler. 

Unknown on how significant a rebuild this will be as the damage is pretty bad (e.g. cracked frame, etc).

Will evaluate and decide, but this thread has me inspired!

[Howie]

Lookin good