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1977 Skidoo Olympique

4200 Views 8 Replies 3 Participants Last post by  gigerous
Hi all, I am new here and I would like to say Hi

My question and kinda problem is

I have a 77 Skidoo Olympique 340 twin. I have had to restring the pull-start and put a new spring on the pull-start. I have replaced the sparkplugs and gapped them to factory specs .20

I have all new mixed fuel in and all the lines have been cleared of the old fuel. The oil/gas mix is 50:1 as per factory specs.

I have checked the fuel filter and its clean, I have cleaned the carb of all resin deposits.

Here is a little history of the machine: It was hit while piled in the snow by a front end loader. Only cracked the front cowling and dented the muffler. The muffler does not stay in that good but I have wedge it into the manifold.

I can get it started but it quickly stops after that, I can prime and watch the fuel go in. Its starts then bogs down. I do that for a bit and then it slowly just doesnt want to go anymore.

Just wondering if you guys have any suggestions on what I should check, try next.

Or should I just forget it and use my other sled. I have a 1990 Yamaha Enticer 400T. That one I got running but its only problem was the choke plunger was missing and a clogged fuel filter.

I am trying to learn how to do all this myself but without manual its hard. I am on a limited budget, hence the old machines. Hopefully in the future I will be able to afford better toys. But for now this is me and what I can do.

Thanks in advance for any help. You can post the answer here or email me (Or both :) )
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Hi gigerous. That's exactly how I started. Now I've got 8 sleds in various genres.

On the 340 it sounds to me like either a fuel starving or excess condition. Pull the plugs and see if they are wet or dry (before you prime or after it fires) While you have both plugs out beg/borrow or steal (don't steal it's bad!) a compression tester and give it a few pulls to find out if the sled still has enough and equal compression. (Roughly 125psi or better in each with about no more than 15 psi difference). When you prime and start it, do you give it a little gas or a lot to keep it going or do you start it at idle.

In either case, unless it is bad compression, my best guess is excess fuel and you have to use full throttle to start it.

Do you know if that sled has the tillotson or mikuni carb?

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I think.... therefore I sled
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Two '94 Indy XLT SKS
Well i have a few suggestions for ya as i learned to ride on a 77 olympic, which by the way we still own and use. If the sled will stay running if you keep priming it, i would guess its a fuel pump, can you see gas in the line from the pump to the carb? If that checks out ok then make sure you have a vacuum pulse from the crank-case. Take the vacuum hose off of the fuel pump and have someone pull the motor over with the ignition OFF. You should be able to feel pulsations, if you dont you are looking at some engine work, if you do things are looking up. Now on our 77 we had the spark plug boots or caps or whatever you want to call them go bad. Make sure that you are getting spark to both cylinders and that it is a nice blue spark. Other than that you may want to clean the carb and make sure that your floats are working properly. Let me know how things go


Polaris is my way out - Other people just use a door.
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Thanks for the info,
When I went to start it, I just gave the prime one squirt, and pulled. It took about two pulls and starts and then bogs down.

It seems when it rains it pours for advice. (THATS GOOD, IM NOT COMPLAINING)

My buddy also told me to do a spark test with each spark plug out of the hole to make sure I have spark, then also to try a little bit of mix (a couple table spoons) in each spark plug hole, if I have spark, to make sure that the engine will run. If it does when I put the fuel right into the engine like that, he suspects that I probably might have a float problem. I guess he means the float and needle for the fuel. I found a picture of my carb on the net (Its a markuni by the way) and I picked up some carb cleaner. He said to take it down to the needles and soak it for 24 hours to get rid of any residue. He also said if I have a little rubber ring on one of the needles and it is worn out or anything it will have to be replaced. Additionally, he said the needles should be sharp and if they are flattened and stuff that might need replacing.

Well, I will try that, and also the stuff you guys suggested. I hope to get it running. I was in the Skidoo dealership the other day Drooling over a 800 Triple Touring Sled (Skidoo) and my gosh. It was a beaut. I am in to the comfort and long rides and this thing was like a luxury car. One day, I will be there. But for now I am doing the bottom to the top method of owning sleds.

Never know, I might win the lottery then I am all set.

p.s. I really appreciate the help guys, it is nice to have a place to hang my helmet and ask questions so I can try to save some money.
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Anytime gigerous! Hey I've got to know, where does your login name come from? Its rather perplexing.


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I think.... therefore I sled
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Two '94 Indy XLT SKS
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Okay. My name actually has a two fold meaning.

I love H.R. Geiger (I think thats the spelling of his name)

I mean, I love his art and the way he think in his designs, and if anyone didnt know he worked on Aliens, Species and movies like that.

That would take the Giger part of my name

The ous part was because I used to play (I just quit today due to lag and stuff) Diablo 2 and the name Giger was taken. So I chose Gigerous. I kinda just kept the name after that.
very interesting. thanks for sharing!


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I think.... therefore I sled
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Two '94 Indy XLT SKS
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hey gigerous, let us know how every thing goes. Oh by the way, i dont agree with the sharp needles thing...you should be fine with the ones you already have. The air screw is not sharp nor is the idle screw. and your mixture needle i guess can be considered sharp but that should never have any wear on it at all. Just give the carb a nice cleaning and go from there.

Polaris is my way out - Other people just use a door.
Well guys,

I soaked all my carb pieces over night. After work I will go and put it all back together and see how everything goes. I didnt touch any of the needles. And yes the lower end needle was kinda star/squary with a tip (not sharp) and the adjustment screw with a spring on it wasnt that sharp. The other needle from the throttle was about the sharpest and that wasnt super sharp anyways. I got royal crap from my wife when I did the carb in the house. That carb cleaner spray sure does leave a stench in the house after you use it. I figured I might be able to have the smell go away before she figured out anything. Oh well, she will just have to build me a damn garage then. LOL
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