I just bought a new/used quad. It is a 2005 Prairie 700 w/ less than 400 miles/100 hrs on it. It was used on a farm thus the low miles. It is in excellent condition except the back tires need replacing (they swapped tires before the sale). When the machine is running, it sounds good & seemingly runs perfect.

There is 1 problem though. It doesn't have alot of power & top speed is only ~ 40 mph. I know that this can't be right. Although I just bought my 1st quad in ~ 25 yrs I do have experience riding family members quads (2003 Grizzly 660 & ~ 2005 Can Am Outlander 800) & know that this quad should go much faster & have more power.

Aside from the lack of huge power & total lack of speed, the test ride went fine. It did take me a bit to get used to the engine breaking (which I only knew about thanks to viewing this forum prior to going to look at the quad). After looking at alot of quads, I bought this quad even with the seemingly obvious lack of power/speed. I guess I just figured that it was probably something very easy to fix/update. Hopefeully, I didn't make a $2700 mistake!

I'm not a real mechanical guy but can anyone give me some pointers on what to look for to increase the speed/power?

I really bought the quad just to have something to ride & take my 7 yr old son out w/ his Polaris Scrambler 90 on some single track fire roads. If I don't fix it (whatever is wrong with it), is it going to cause me more problems?

Thanks for any help,
Anthony

 

Getting used to egnine breaking?
Man, how many engines have you broken so far?

OK, that's a little humor there (you meant to say "braking").
For your problem, I have 2 suggestions:

1. CVT Belt deflection
It may be too much and the you are not getting the full speed out of it even though engine is revving up to its max just fine. The spec is 22-27 mm when pushed down in the middle of the belt. If you don't have right tool/procedure, have a pro do it. You may need a new belt ($70).

2. Cam Shafts
When I read that quad was used for farm work.. I said "rounded cam lobes!". Open up the valve cover and inspect the cam lobes which might be rounded off due to extended low rpm use at which there is not much oil getting on to the top of the engine. It's a lack of lubrication failure. Check cylinder compression as well.

 

Hayashi - thanks for you quick response.

I can handle #1 below I familiar with that.

For #2, I'm not familiar at all - if that ends up being the issue, is that an expensive fix or ???? I'm assuming that is something a dealership would have to fix????

Anthony

 

The #2 issue, cam shaft, is not too difficult either. Just remove the old one and install the new one. But you must check the cam timing which can be little tricky. You have to make sure camshaft sprocket and the crankshaft/rotor are at the right position - page 5-19 of the manual explains very well. I have a 2004 Prairie 700 also (among pother quads) and like it the most.

 

Ok. I finally got back to this (I'm in the process of remodeling a home before moving in). Before I got started with taking off the belt cover I happened to take off the air cleaner. I noticed that only 1 cylinder is being "activated" when I rock the throttle. What I mean is when I look down the two holes down in the air cleaner, only one has any movement when I rev the motor... Does this change the diagnosis?

 

Yes!!!
Just to make sure, check again.
With the engine turned OFF, the boht butterfly valves on the carb should be moved equally when you thumb the throttle.
If not, you have throttle cable to carb linkage problem, and/or front & rear carb synch issue.

 

"With the engine turned OFF, the boht butterfly valves on the carb should be moved equally when you thumb the throttle.
If not, you have throttle cable to carb linkage problem, and/or front & rear carb synch issue. "

I checked with the engine off & NEITHER valve moved. When I started it up - still had 1 moving & 1 not moving. I used a screwdriver to see if manually moving the slide did anything - it didn't. I used a long screwdriver to manually move the slide that wasn't working to see if it was froze up or something... It slides just the same as the other one... When I moved it, nothing happened, It didn't rev the motor or anything... Should it?

I just haven't had time to take anything apart or anything - I did try to tell if the motor was getting hot or not but honestly, I couldn't really tell. I did notice a small amount of gas leaking from that front carb that the slide doesn't seem to be working on - is that just by chance or is that another clue...?

 

I think you and I have been referring to two differenct valves.

You are referring to vacuum slides, black plastic piece with needle jet in the middle.

I am referring to throttle butterfly valve, round metal plate with 2 small screws along the centerline.

Which one is it?

If you are referring to the vacuum slide, remove 4 small screws for the carb cover and check to make sure spring and needle jet are in place not obstructing the motion of the vacuum slide. If all OK, then that cylinder is not creating enough vaccum to move the vacuum slide. Do compression check and compare two cylinders.

 

I had the same problem with my 05 700... Read all the posts related to a lack of power. In my case it was the forward cylinder- the spark plug was fouled. I recently got my P700 and noticed the found that the crankcase was overfilled. I took it for a ride up the rode and was only able to get it up to about 40 mph. It began to blow some oil as I was climbing up the side of a mountain and I turned it around and headed back to the shop. Turned out the overfilled crankcase oil was blowing thru the carb and fouled the plug. I changed it out and the problem was fixed.

 

Overfilled crankcase oil?
Did you put too much or did it rise too high by itself like fuel coming into it?
Yes, that will foul the plug. The excess amount of oil (& fule mixture) in the case will be pushed back into the air box, then it will be sucked into cylinder, contaminating/fouling the plugs. It's important to fill right amount of oil.