Post by olyman on Jan 23, 2020 12:52:48 GMT
oly_man
I have a 68 299 engine I'd like to try a mikuni on. I see conflicting data that a 75 or 76 oly300 single came with one. Maybe it was a kit you could buy . Anyone know what carb that was? Or what internal hardware would work with such an engine? A 34??
TIA
Banoe
I have a chart that says VM 34-103 kit for 1976 Oly. No other info listed.
oly_man
some technical manuals show the internals of a specific mikuni with the second number like that. But those manuals show the 76 300 as having a tilly
Bones
My thinking is there was never a 300 cc single with a Mikuni from the Valcourt. I have a chart with the Mikuni kits that were available from Ski-Doo for the `76 model sleds and will have a look when I get a chance. I am thinking the kit that Banoe is seeing for a 76-300 is for the 300 twin.
My thoughts on a Mikuni for a steel jug 300.....They are kinda tough to find but I think a 28 mm from a Elan would be a great starting point. Other than that I would attempt to find a 30mm I go with that.
Slight draw back of going to 30mm plus on a HR pattern is the selection of off the shelf mounts. My thought is get one for the Elan, the 30-34 mm carb will squeeze into it, it is tight/stretched but will work.
I have discussed it on this board before but, what ever mount you select use one that has a bit of length ie the Elan one. With a short / close mount the carb will constantly dribble out the over flow at idle cause of the shaking of the lunger . With the Elan style mount there seems to be enough of a vibration damper to stop the over flow problem, at least that has been my experience.
Bones
Bones
The 1976 change up kit with carb # VM-103 is for the 76 - 300 TWIN.
Bones
oly_man
thanks for the info guys.
i may put a 30 on there & just see what happens. I'm likely going to be running this thing even in the warm weather so there is lots to learn on it.
Cheers
oly_man
Well didnt get to this again until recently, and the engine ended up in my 68 oly. The carb fits nicely, and it starts so easy and idles nicely too. She revs up ok from what I can tell on a stand, so next is to wait for snow again... nothing but rain in the forecast.
Once I know the setup I have works good i will post the settings.
I'm also in the works of adding superOLY tabs to the hood so I can bolt it down with 4 bolts instead of the 20 I used to use!
Bones
OH oly_man you are gonna cause a stir with the Tilly fans
I told you in a previous post, bring er on out to SE sask, lots of snow and trails here. The last couple days has been -45C wind chill but this week end is gonna be gorgeous. I am heading out on groomer tomorrow to make a nice trail just for you and the Mikuni equipped Oly
Bones
oly_man
Thanks Bones - Oh I still run tillies! My 292 runs great with the big old HD! EEESH thats cold!!! Hasn't been that cold here in many many years! Hope you get lots of miles covered - many will be enjoying it!
69nordic
I put a 30 mm Mikuni on a 72 Oly 299 it was from a one cylinder Arctic Cat.I did not use the elan mount as the quality of the new ones is very poor when they crack on the Elan I wrap them with electricians high voltage rubber tape and then cover with Scotch 88 or 33 electrical tape.
I used the original spacer block and the intake boot for a 78 oly you can find actual Mikuni boots cost more but better quality/
Mine had the choke plus primer the best of both worlds.
After lots of trial and error it worked very well dribbled the very odd time/
When tuning start with the idle circuit and work your way to high speed last/
Have not run the sled in 5 years here is what I might remember.
Cutaway 3
idle jet 35
main jet 160 170 was a tad rich
needle clip postion 2
I was going to put the 28 mm from an Elan on for comparason but never got around to it the 28mm also uses a 160 main jet.
I use ty wraps to losely support my Elan carbs/
Kash
oly_man
So I meant to update this post a while ago but have the time now. I got one weekend to run the 299 with this carb on it and it ran great. Started rich on the low RPM but changed the pilot to a 35 and it was set. Weather wasn't too much below freezing. This is what I ended up using:
VM30 from a 340 twin
220 main
35 pilot
159-Q0 needle jet
2.0 slide
6DH2 needle, clip in the middle (3rd pos'n)
Next project for this sled is to deal with the gas tank. It's cracked in several places and has been for years. It's also got lots of crap inside including bits of rust. So I'm thinking an Elan tank. She's always been a fun sled and a clean tank that doesn't leak would make it that much better.
I have a 68 299 engine I'd like to try a mikuni on. I see conflicting data that a 75 or 76 oly300 single came with one. Maybe it was a kit you could buy . Anyone know what carb that was? Or what internal hardware would work with such an engine? A 34??
TIA
Banoe
I have a chart that says VM 34-103 kit for 1976 Oly. No other info listed.
oly_man
some technical manuals show the internals of a specific mikuni with the second number like that. But those manuals show the 76 300 as having a tilly
Bones
My thinking is there was never a 300 cc single with a Mikuni from the Valcourt. I have a chart with the Mikuni kits that were available from Ski-Doo for the `76 model sleds and will have a look when I get a chance. I am thinking the kit that Banoe is seeing for a 76-300 is for the 300 twin.
My thoughts on a Mikuni for a steel jug 300.....They are kinda tough to find but I think a 28 mm from a Elan would be a great starting point. Other than that I would attempt to find a 30mm I go with that.
Slight draw back of going to 30mm plus on a HR pattern is the selection of off the shelf mounts. My thought is get one for the Elan, the 30-34 mm carb will squeeze into it, it is tight/stretched but will work.
I have discussed it on this board before but, what ever mount you select use one that has a bit of length ie the Elan one. With a short / close mount the carb will constantly dribble out the over flow at idle cause of the shaking of the lunger . With the Elan style mount there seems to be enough of a vibration damper to stop the over flow problem, at least that has been my experience.
Bones
Bones
The 1976 change up kit with carb # VM-103 is for the 76 - 300 TWIN.
Bones
oly_man
thanks for the info guys.
i may put a 30 on there & just see what happens. I'm likely going to be running this thing even in the warm weather so there is lots to learn on it.
Cheers
oly_man
Well didnt get to this again until recently, and the engine ended up in my 68 oly. The carb fits nicely, and it starts so easy and idles nicely too. She revs up ok from what I can tell on a stand, so next is to wait for snow again... nothing but rain in the forecast.
Once I know the setup I have works good i will post the settings.
I'm also in the works of adding superOLY tabs to the hood so I can bolt it down with 4 bolts instead of the 20 I used to use!
Bones
OH oly_man you are gonna cause a stir with the Tilly fans
I told you in a previous post, bring er on out to SE sask, lots of snow and trails here. The last couple days has been -45C wind chill but this week end is gonna be gorgeous. I am heading out on groomer tomorrow to make a nice trail just for you and the Mikuni equipped Oly
Bones
oly_man
Thanks Bones - Oh I still run tillies! My 292 runs great with the big old HD! EEESH thats cold!!! Hasn't been that cold here in many many years! Hope you get lots of miles covered - many will be enjoying it!
69nordic
I put a 30 mm Mikuni on a 72 Oly 299 it was from a one cylinder Arctic Cat.I did not use the elan mount as the quality of the new ones is very poor when they crack on the Elan I wrap them with electricians high voltage rubber tape and then cover with Scotch 88 or 33 electrical tape.
I used the original spacer block and the intake boot for a 78 oly you can find actual Mikuni boots cost more but better quality/
Mine had the choke plus primer the best of both worlds.
After lots of trial and error it worked very well dribbled the very odd time/
When tuning start with the idle circuit and work your way to high speed last/
Have not run the sled in 5 years here is what I might remember.
Cutaway 3
idle jet 35
main jet 160 170 was a tad rich
needle clip postion 2
I was going to put the 28 mm from an Elan on for comparason but never got around to it the 28mm also uses a 160 main jet.
I use ty wraps to losely support my Elan carbs/
Kash
oly_man
So I meant to update this post a while ago but have the time now. I got one weekend to run the 299 with this carb on it and it ran great. Started rich on the low RPM but changed the pilot to a 35 and it was set. Weather wasn't too much below freezing. This is what I ended up using:
VM30 from a 340 twin
220 main
35 pilot
159-Q0 needle jet
2.0 slide
6DH2 needle, clip in the middle (3rd pos'n)
Next project for this sled is to deal with the gas tank. It's cracked in several places and has been for years. It's also got lots of crap inside including bits of rust. So I'm thinking an Elan tank. She's always been a fun sled and a clean tank that doesn't leak would make it that much better.