4 Speed Femsa conversion to Motoplat

[BufoBolt]

Hi All, I am trying to replace the Femsa points on a 360 Husky 4 speed motor with an early Motoplat set up I have. There are no model markings on the unit but the back plate and flywheel fit the 4 speed motor fine. Can anyone identify what model I have (photo) and how to go about setting it up.

There are two sets of coil wires (ie two blue wires) coming from the points and what must be a lighting circuit(s?). Is this a twin spark set up and if so do I have the correct coil? Can it be modified to be used as single spark? Kris

 

[Crashaholic]

I'm surprised that the Motoplat flywheel fits the Femsa stub shaft on your 4 spd, or should I say fits it correctly. Take a closer look just to make sure. I've attached PDF of the different shafts used on Huskys from 69 to 88.

Sorry I can't help as far as setting up the Motoplat you have, not that familiar with them. I have read that they were somewhat problematic in the 70's. Some may feel that the Femsa is complicated to set up but when done correctly its dependable.

 

[Crashaholic]

Heres another PDF you find useful.

 

[2premo]

it might be a small shaft, like a 125, but there is no advance built into them
if you mount it, use a dial indicator for your advance setting and a drill bit goes between the mag and stator to set the timing
look at the 87 owners manual to see the drill bit type adjustment
good luck wit your project
upload pictures if it works

 

[stormer254]

Very useful info on the Motosplatt, have you got the same for SEM by any chance?

 

[Crashaholic]

Stormer, I remember running across detailed SEM testing info but couldn't find it however I came across this other pdf SEM ignition info that may be of interest to you.

 

[Crashaholic]

Bufobolt, heres an interesting article from a Husky News letter regarding how someone did a Motoplat conversion on their 4 spd. Seems that this guy used the Motoplat stub shaft from a 72 450, probably a CR. He says it was a Desert Master but that's incorrect as the DM came with a Femsa. I know this from owning two 73 DM's and one 72 CR in my life time.

Another source for how to info would be LeFevre at Vintage Husky. I noticed on his restoration webpage a picture of a restored 4 spd with a Motoplat coil hanging from under the tank. John is very willing to help with things he doesn't consider his own trade secrets.

 

[stormer254]

Thanks , I have several SEMs I need to investigate.

 

[BufoBolt]

Hi All, thanks for all your help and sorry for not replying sooner. I have to confess I gave up on Motoplat and fitted an original FEMSA points iginition. Maybe I threw in the towel a bit too soon! Will go through the material posted and try again. The unit I have definately fits the 4 speed motor with crank end suited to FEMSA iginition. I have just found Husky Club newsletter #4 (see pdf). I think I must have something like model 602 which is described as twin spark. No mention of lighting circuit. Still wondering if I have the correct coil. I will try fitting it and see if I can get a spark.

 

[Crashaholic]

Here a 1972 service bulletin I came across that says the Motoplat armature plate and flywheel are a matched pair and replacing them individually can result in ignition timing being off by as much as 3.5 degrees. I've never heard of this before. Probably applies only to the early Motoplat units.

 

[2premo]

Here a 1972 service bulletin I came across that says the Motoplat armature plate and flywheel are a matched pair and replacing them individually can result in ignition timing being off by as much as 3.5 degrees. I've never heard of this before. Probably applies only to the early Motoplat units.

no that applies to all the years, look closely they are numbered as a pair, the same number is on the stator and mag
in manufacturing they matched them set the position for timing and drilled the hole that set the timing position

 

[Crashaholic]

2premo, thanks for verifying that it makes sense. I think about the individual Motoplat stators and flywheels on Ebay and how they're timing is not accurate without the other half. .05-3.5 degrees wouldn't be enough to make the bike not run but I would think that 2 - 3.5 degrees would affect performance.