Hey guys,

Ok...looking for some answers here. I live in Western Wa. and own a couple Prairie 700's. The second one I bought(used) shortly developed a knocking sound as it's being revved. At first thought it was the valves but my brother and I adjusted those and still knocked. So, we let it sit as an initial diagnosis from a dealer was that the crank shaft bearing was out of it. Too much at the time to repair. Well, now we're looking to get it going and took it to another dealer. Their initial diagnosis was the valves...but no such luck on the knocking sound. They compression tested it and said the front cylinder was at 134 psi and the rear 100 psi. However, in their notes they say the knocking is coming from the front cylinder which seems to contradict the compression test. They also say the connecting rod is ok...but there is too much clearance between piston skirt and cylinder valve. So then they were going to dig into it that way. Pretty much, they're just going to keep going until they actually find something. When would it stop ?? This isn't making sense. My brother had one of these machines blow up on him because another dealer didn't tighten the valve covers back down after adjusting them. And they didn't cover it. We're having huge doubts about the service work being performed here in the Puget Sound area. So, we're going to take it upon ourselves and friends to help us out. Or anyone know a good ATV mechanic in this area? What's it sound like to you guys?

 

Oh...I forgot something. Another reason to doubt the service work: I've pulled the plastic off the machine to access the motor(anyone who owns one of these knows that just seeing the motor is difficult to do without doing so) and the valve covers are still full of dust and such. Think we got took on that valve job.

 

I used to have a 2004 Prairie 700 until last year when I sold it. I had a zero problem during my ownership (2004-13).

Valves being out of adj don't make a knocking sound. They make ticking noise on my machines (cars, atvs, bikes, etc.).

Knocking sound is more likely either big end rod bearings or cvt having worn out shoes on drive converter. Use a mechanic's stethscope to find out exactly from where. Having such different compression from cylinders is a concern.

Here is another way to find out. If the engine oil has more than 10 hours of run time, driain some send out to a lab for analysis. And see if metal debris are detected (& they can tell you exactly what they are). It costs about $10 to $20 per test. I use a Polaris Lab (that has nothing to do with Polaris ATV!).

 

Hayashi,

Thanks for the input. I have been reading about 750 bf v-twins where the crank shaft bearing has gone out and has produced metal debris. I think it's definitely worth it to do this. I have heard most input from friends and friends of friends suggest that it could be one of the rocker arms. They've mentioned the motor would be toast by now. Just so many variables. Tomorrow, doing compression test of my own, and the stethoscope has been mentioned. I don't want to dig into the bottom end if it's something in the top. Trying to at least get an idea. Thanks for the input. I love these machines. I have an '06 with little to no issues. This machine has plenty of power...it's cleaner than any of our other machines. Just has this knock that I know isn't good! Thanks for the input!

 

GO back to that dealer and ask them to explain KACR to you. KAWASAKI AUTOMATIC COMPRESSION RELEASE. No way you would have that high of cranking compression. service manual says (650) should have 81psi. The 750 newer service manual calls for 36psi-86psi. Its very common to replace the crank and rods in a Kawasaki ATV V-TWIN. I would set valves and remove thee primary clutch. Worn clutch can make some knocking sound. valve will tick. Those engine are some of the early ones that had bad timing chains. If the chains are bad, carbs out of sync, valves out of adjustment, 1 cylinder could be running a lil ahead of the other and it will make a knocking sound. So a full tune up, carb clean and adjust, valve adjust and see what you hear.

 

Sorry to bring up dead thread but I'm having that problem. I live in modesto ca and i bought a quad 2 days ago, and the guy I bought it from lives down a couple of blocks away from me and he said quad should be good not stolen or anything. So today I called up the non emergency police number and dmv to run the vin and both said there's nothing on record for the quad. The dmv guy say they can't do nothing about it unless I get a bonded tittle some shiet like that and i shouldnt bought it and blah blah blah.Then when I read what u said that all I need is a bill of sale and to check the Vin. Well nothing on the record. What should I do? I made an appointment next Monday afternoon. I'm go with a bill of sale to see if things might be different. Any help from anyone is appreciated. Yes I'm a newbie I don't know anything just starting something new