FuzzButt
New member
My Fathers 700 seems to have an issue. Since I am 200 miles away from it I cannot do any work on it right now and this might end up being a summer project anyway.
High 8000 miles. Had varing compression between the cylinders with the lowest being the left one when a shop did the preseason work for him. The power valves were cleaned and carbs as well. Has had about 500 miles on it since December.
I figure we need to do pistons/rings on all 3 and a set of seals and gaskets. He has compression on that cylinder but using the finger test it is not at all accurate.
The sled runs. He even drove it back to his house.
Ideas?
High 8000 miles. Had varing compression between the cylinders with the lowest being the left one when a shop did the preseason work for him. The power valves were cleaned and carbs as well. Has had about 500 miles on it since December.
I figure we need to do pistons/rings on all 3 and a set of seals and gaskets. He has compression on that cylinder but using the finger test it is not at all accurate.
The sled runs. He even drove it back to his house.
Ideas?
So what's the issue, the varied compression?
If by left cylinder, you mean the left when sitting on the machine (i.e. the PTO cylinder) then it is supposed to have lower compression. Yamaha did this to eliminate the need for staggered jetting in the carbs.
If by left cylinder, you mean the left when sitting on the machine (i.e. the PTO cylinder) then it is supposed to have lower compression. Yamaha did this to eliminate the need for staggered jetting in the carbs.
Read this:http://snowmobile.off-road.com/snowmobile/article/articleDetail.jsp?id=195965
About a 1/3 of the way down.
About a 1/3 of the way down.
FuzzButt
New member
Ya PTO cylinder. We figured on a refresh after the season was over but nothing quite this early. Ya knew about the varied compression but that would account for the fact that the 3 cylinders were quite a bit different. From the mag side being the highest (Sorry don't know the numbers as he does not remember them) and the PTO side being the lowest. They were quite a bit different.
Who knows maybe it is something else. It sounds like it is missing a cylinder.
If I can get to the sled this weekend I might start looking around at it since we have a heated garage it is parked in. Only down fall is there is no internet there. That and we do not have a service manual specifically for the viper yet.
Who knows maybe it is something else. It sounds like it is missing a cylinder.
If I can get to the sled this weekend I might start looking around at it since we have a heated garage it is parked in. Only down fall is there is no internet there. That and we do not have a service manual specifically for the viper yet.
FuzzButt
New member
Correction.
I did not read the email sent to me fully and it seems that the sled is here in Waterford do I will be taking a look at it this week sometime if work slows a bit.
I did not read the email sent to me fully and it seems that the sled is here in Waterford do I will be taking a look at it this week sometime if work slows a bit.
You compression on the MAG and CTR should be within 10 lbs of each other, even that is a lot of difference. Then the PTO should be a fair bit lower, think about 12-15 then the other two, but someone else like MrViper700 might know for sure.
Well it could certainly use a re-ring with that many miles on it. I'd measure the pistons while you have it apart and make sure they are still within spec, but they probably need to be done too. If it's running then I'd wait until summer to fix it, but it doesn't sound like it is.
Well it could certainly use a re-ring with that many miles on it. I'd measure the pistons while you have it apart and make sure they are still within spec, but they probably need to be done too. If it's running then I'd wait until summer to fix it, but it doesn't sound like it is.
FuzzButt
New member
I heard it still ran the trails at 80+ on the 2 remaining cylinders just fine.
I'm going to their house tonight to take a listen to it. Don't have too much time to tear it down but will take a look at the obvious things for sure.
I'm going to their house tonight to take a listen to it. Don't have too much time to tear it down but will take a look at the obvious things for sure.
FuzzButt
New member
Well took a look at it and here is the result.
Pto Cylinder has 125 pounds of compression
Both of the other cylinders has 137 pounds.
We changed plugs and fired it up and it seems to be running fine now. It might have been something as dumb as a plug. It was running a bit rich/loaded up but I was not going to run it too long as it would have ruined my wool jacket with the smoke in the shed the sled was parked in.
Hope that is it cause we are going back to the Higgins Lake area on Friday.
A refresh is probably still going to occur this summer.
Pto Cylinder has 125 pounds of compression
Both of the other cylinders has 137 pounds.
We changed plugs and fired it up and it seems to be running fine now. It might have been something as dumb as a plug. It was running a bit rich/loaded up but I was not going to run it too long as it would have ruined my wool jacket with the smoke in the shed the sled was parked in.
Hope that is it cause we are going back to the Higgins Lake area on Friday.
A refresh is probably still going to occur this summer.
daman
New member
If she's got 8000 on her it's time for a refresh fuzz,,drop me a email i got a
FSM for ya....
FSM for ya....
FuzzButt
New member
Daman, What is an FSM?
7600 miles actually not that that matters. Certainly time to go thru it since he wants this sled to last quite a few more years. Of course all I ever hear is how hard the suspension is and if an M10 will work in there. Everytime I counter with get the shocks redone in "Cruiser mode" and it will be fine. Though we do have a sled with an M10 in it in our fleet and it really is nice.
7600 miles actually not that that matters. Certainly time to go thru it since he wants this sled to last quite a few more years. Of course all I ever hear is how hard the suspension is and if an M10 will work in there. Everytime I counter with get the shocks redone in "Cruiser mode" and it will be fine. Though we do have a sled with an M10 in it in our fleet and it really is nice.
daman
New member
Factory Service Manual..for the vipe....FuzzButt said: