Yamadoo Trouble?

[dirk_03]

I pulled the sled down tonight and looked at the carbs, intercooler, charge tube, etc. I have not found anything that throws up a red flag.

My cousin seems to think it is electrical related. Like maybe the coils are arching. I will be testing this tommorrow and hopefully can find something out. I am not sure if the vectors had the same issue that the rx1's had with the coils but i guess I am to the point that i am willing to try anything.

 

[dirk_03]

I am sitting here thinking and I rode the sled early in the year and it felt very good and I am trying to think about the things that I changed and the one thing that had never came to my mind until now is that I hooked up the headlight as I was not running it before we went out west.

Could it be pulling enough voltage that at higher rpms the coils are not getting enough juice?

 

[dirk_03]

Anyone have any thoughts on the compression and the possibilty of not enough current?

 

[kinger]

I honestly dont think you can pull enough current to restrict the coils with the set up your running I can see if you had a winch on there or something but, to me it must be in the cam timing, header design, or clutching.

 

[dirk_03]

I honestly dont think you can pull enough current to restrict the coils with the set up your running I can see if you had a winch on there or something but, to me it must be in the cam timing, header design, or clutching.

Well I do have the big fuel pump and the headlights. I don't know i am just thinking out loud.

The sled did run good this year. And the two major things that I changed were to the Vortech BOV and added the headlight. I don't think that the cam timing is off and it will be the last thing that I check as it involves pulling the valve cover off. I know that the motor was timed perfect when I put it together. I checked and rechecked it mulitple times. I also made sure to ensure that the timing chain tensioner was at the correct tension by turning the motor over by hand many times. I was assured by a reputable engine builder that my cam gears likely didn't move if I torqued them and used red loctite which i did, and then I rechecked the timing again after turning the motor over a few times.

As far as the header design I know it works it made power last year and It is just about the same as imulses header. and like I said it made good power the first few weeks i rode it this season then I added the headlihght and vortech BOV right before we went out west and hardly rode it. then It did not work good out there and doesn't work good here now abck in MN.

 

[SPEEDMAX]

Make sure coil cap are not arching 03,04 cap where not good,also ck.fuel pressure 4psi at idle you need 3 to 4 psi more than boost. afr at idle 13 and under boost 11.5 to12

 

[SPEED]

My sons Z1 just had same symptoms as yours this past weekend ,looked for everything, ended up being the rod had come off the wastegate (circlip had fallen off)
Check your carb boots to the block also

Disconnect your headlight and plate off BOV (just to eliminate possible)

If your running and chop throttle can you hear the BOV blow off ? If not check for sticking open
Just a few ideas

 

[Ski-Dooin' it]

double check your exhaust gasket.. i had some header bolts rattle out, and I think it allowed it to burn out a section of the exhaust gasket.. header leaks really make them sluggish out of hte hole, and dont make good power on the top end.

also, what say your boost gauge?? my first guess would be to try and plug up your BOV as well, a small leak can cause major tuning headaces.

 

[dirk_03]

Well here is what i all did,

1. Removed carbs, intercooler, charge tube
-checked carb boots, checked carbs, pressure tested intercooler and charge tube.
2. Installed a little stronger sping in the BOV.
3. Cleaned the Coils, die electric greased them
4. Reinstalled everything.


RAN the sled, Seemed like it maybe was a little better but. . . . . still wasn't pulling the rpm.

Then I changed the clutching from the 48 degree helix to a 44 degree helix.

Here is what I am thinking. The sled was really weird out west. When I would be on the trail below 5 lbs of boost the BOV would chatter. And then when I would get on it it would hit very hard once over 5 lbs of boost. At the time I thought the BOV was leaking. Now I think that the clutching was just far to senstive, and loading and unloading the motor or something maybe shifting up and down to fast.

So my final verdict is that the clutching is just not right still. I thought if anything the clutching was not heavy enough.

Where i think I need to go from here is maybe to a little lighter spring in the secondary or a little stronger spring in the primary to up the engagement rpm a little. As it engages at like 3500 rpm now. I think that is just to low making the low end feel weak.

I bought a yamaha jackshaft today on ebay and am hoping to remachine the shaft to work with the ski doo gears and run a yamaha secondary on the sled. The clutching was perfect last year with the yamaha secondary in the vector chassis. Now this year I have a less compression and I think I need to bump up the engagement rpm.

I am going to make a new post in hopes to stir up some clutching gurus to help me out.

RAN The sled. It felt immensely better.

 

[Ski-Dooin' it]

I had a local company just cut the end off my doo shaft, then weld on a peice of chromoly and cut yami splines into that, if you get a yami shaft, then you could just have them cut in the center(inboard of the clutch side bearing) and weld them back up. IMO, yami clutches are the way to go.. so dumb easy to tune, then you can clutch it much easier. I know I was having some clutching issues for a while and overloading the motor and it kicked #*$&@ under low load, but when you got in any amount of fresh snow climbing, it just sorta fell on its face