I went to Chadwick Mo. riding today and a friend of mine riding a 660Griz. said that his local dealer said not to hold his quad at full throttle for more than 4 seconds. He said that only a 2-cycle engine was designed to be held at full throttle for more than that. Have any of you heard that holding 4-cylce wide open would hurt it? I thought our rev limiter would protect our engine if held at full throttle. What do you think?

 

Encore most modern engines can be held at WOT. There are limits of course, but 4 seconds is a joke, more like 40 minutes might be a problem for some motors. Motors 101, perhaps his dealer ought to here this too, 1. Exceeding the stregnth of internal parts- also known as over revving OR shockloading- this is the primary sudden failure cause of motors. Rev limiters and technical barriers designed into many motors by their producers limit these "ID, 10, T" type errors. 2. Overheating, this causes warpage, stress, and in severe conditions meltdown. 3. Lack of lube, causes excessive wear, the wear particals overwhelm the engines filtering capacity.

There are of course zounds of other reasons for engine trouble, but they can be broken into one of those three classes, (like detonation=shock loading, lean mixture=piston overheat ect.)

Now where the hell in all of that does throttle position fit??? It doesn't, get the motor broken in and tape the throttle down at WOT, and foggetaboutit untill the overheat light comes on. [img]i/expressions/face-icon-small-happy.gif[/img]

 

the dealers also state that NO 4 WHEELER is designed to go above the floorboards in water, lmao!!! now, how boaring would it be if no 4x4 could go above the floorboards in water. one thing is for shure, noone could ever tell us about how bad they got stuck, lol! they also state to break in an engine easy. now, my uncle( god rest his sole) built dragster engines in his day. whenever he finished building engines, he would start them, and then peg the carb for about 5 seconds! this is not the way we are told to break in an engine, lol! he has done it to every car, dragster, or street rod he has ever built, till his death. i used to look at him like he's crazy, but he must have known something i still dont. he is remembered buy numerous people who still brag about the engines he had built. alot still run the tracks here and in georgia.
just my opinion!!!

my pictures

 

I think the person you spoke to is misinformed. There is a rev-limiter on these bikes that keeps you away from danger territory before the RPM's get anywhere near red-lining.

All that being said...with an eight foot wheel base and a less than four feet wide...how long do you want to go 60+ mph? [img]i/expressions/face-icon-small-smile.gif[/img]

Chucky

 

If I'm not mistaken, the 650s have rev limiters that kick in around 6000rpm(up here in Canada). If I'm not mistaken, I think the big V-twin can take a little more than 6000!!!!! Tape it and hold it there!!!!!! We need a rev limiter that redlines at around 9 or 10, that would be cool!!!!

 

Mich660griz

Sounds like your uncle and I went to the same school. As I've stated in other posts here, I too am an old engine builder and the only way to properly break in a performance engine is like you're going to use it. Performance means run it for all it's worth. If you're afraid to run it trade it in on a Yugo.

This dealer should be run out of business (as should many others) for passing along BS info. There's an old saying, It's better to be thought a fool than to open your mouth and remove all doubt. There's little doubt this dealer needs to clam up.

 

Thanks for all of the info. I passed it along to the guy who told me this. I still think he beleives his dealer. I guess he has had better experiences than I have had with dealers. I love my 650 and love to hold wide open for much longer than 4 seconds!!!