82 XJ750 feels like it needs 6th gear

whoa whoa wait a minute here!!! This is my first bike ever, but my Jeep wrangler, I always shift around 2500 RPM. Thing is a torque monster and gas burner so I don't take it high in RPM.

Figured the same with the bike. I shift around 4K. You gotta be kidding me with this info! Getting new tires Saturday, cant wait to take it out again. I've parked it till my tires come in.

Dano what do you mean by this?

"I also was not use to the RPMs required to take off smoothly until I let the motor breath."

I stutter at take off almost every time. I've driven a stick my entire life. 4 cars so far, all stick, so I know how to work clutches, etc... I stutter almost every time on the bike at take off. Takes me a good 15 -25 yards to get the stutters out and get some pull going. You are revving high while releasing the clutch?

 

You have to realize the type of engine these have. They are essentially a racing engine which has been put into a non-racing frame. On top of that they added the channel which connects the fuel flow into the cylinder - forget what it is called - but helps to better atomize/disperse the fuel providing a better/stronger burn for more power.

Someone mentions their jeep above and shifting at 2.5 k. If that is what it is made to do, then do it. I doubt it is designed for that low a shift point.

I had a friend in college who drove a chevette. He would always shift at something like 2k and putting it in gear, you could just feel the engine lug down and struggle to get any power - he thought he was saving gas. I never could get him to understand it was just the opposite. On the other hand, I was driving a citation and despite an engine powered by gerbils, using proper shifting I could make it accelerate pretty good.

A good way to get a feel for this idea is to hop on a bicycle. At 7-710 miles an hour, put it in its highest gear and look how hard you have to struggle to turn the pedals and you are doing maybe 20 RPM. Now drop it down to 3rd, lets say- whatever gear gets you pedaling at somewhere between 70 and 90 RPM Now your feet are moving around much much faster, but it is flipping easy to push them. Bicycle racers could put high gears in their bikes, but they gear them for an RPM of about 90. That is considered the sweet spot for best amount of torque to expenditure. If you hear the thing lug down when you shift, or when you shift you find that you have nothing from which to continue accelerating, you are shifting to soon, whatever you are driving.

 

RPM was not the right way to say it. It's more the amount of throttle. I find that this bike doesn't want to be eased into motion like vtwins. I am aggressive with the throttle and aggressive in letting out the clutch and then things will lock up and I will let up on the throttle and there you go.
Did that make sence? It's had to explain. Experiment and you will find it.
It's like taking off in an aircraft. You pull back on the stick rather aggressively and as soon as she takes off the nose will start to lift and if you don't respond by easing up on the stick right away you will stall the plane.

 

You shouldn't have to do that "easing back on the throttle". You should be able to fly right up the gears. And these bikes will do that. If yours stalls out lest you ease back like you say, then there is something wrong with it.

 

You misunderstood what I was saying.

When taking off from s stop once everything hooks up if you don't back off the throttle your going to take off which if that's what you want to do great. But I think he was talking about normal starting out in town. Yes these bikes will fly up the gears without throttling back, the subject was about starting out under normal in town conditions and it sounds like he was saying he was doing it like a car which is causing some clutch shutter.

The "stalling" reference was a comparison to taking off in an aircraft if you look back at the post. Something that just came to mind and maybe should noy have used but when taking off in an aircraft when the airspeed reaches the point of takeoff and the plane leaves the ground the combination of increased air force on the elevator and the reduction of drag by the wheels leaving the ground will cause the nose to climb st a increasing rate until the aircraft stalls and that's not good. Like I said not a good comment unless I knew he had piloting experience. My bad.

 

A bit low but fine for normal driving a stock 4.0L is not very happy above 3k but it will drag your house down the street off idle.

I had the same issues/concerns with the RPM's when I got my bike. Now I wind her out when I can.

My other vehicles are a 4.0L Jeep and a 7.3L ford diesel which both redline somewhere near 4k it's a challange to remember to let it rev up if I haven't ridden in awhile. Until I do it the first time. Then I remember.

 

I'm glad you understand where I'm coming from The wrangler is ALL torque, (bigger than stock rear gear too) which is great, but that transfers to my riding. I've gotta change that

 

The 750's Tranny sure does need a 6th Gear or a not-so-close Overdrive 5th.

I'm forever cruising down the Interstate in 5th and looking for another gear in the arrangement.

 

I have that issue as well, I find myself looking for another gear. As was mentioned above gearing down and accelerating will bring it up to speed real quick. Also just throttling up increases speed enough to get out of the way if needed. I am a new rider and I like how quickly I can shift the gears with a quick roll off and roll on of the throttle. It took some practice and now I can do it flawlessly. I love this bike and my greatest fear is that I will break it and not find the parts to fix it. Also I worry about keeping her maintained . I need this site as I have learned so much in so little time about these great machines. I give all the Glory to GOD for giving me something old and XJBikes to keep her running.

 

Have you met Len @ xj4ever? He has your parts.

 

I will check him out!!! does he have a website or just PM

 

Just pm him what you need and he'll get back to you with a list of options and prices. He also includes parts you don't know you need in the quote. Small screws, washers, that sort of thing.

 

Thanks ! Good to know !!!

 

Dang you have a way with words!

And indeed, +1 on contacting Chacal (Len) for what is needed, he has both unobtanium and the common stuff. Always right to buy from our local supplier.

 

It all has to do with stroke and compression.

I was told at one point that the engine in the Ford escort was basically the same as that in a formula 1 race car: short stroke, high compression. I would be driving on the highway and hit an uphill grade. All the cars around me lug down and slow down. I'd drop it a gear and just keep on chugging (I love manuals) It is just like I said with the bike: keep the RPM up and it is easier to pedal than if the RPMs are down. An engine with a shorter stroke is going to spin at higher rpm, and will need to spin at higher rpm than a long stroke engine - which is what is in your wrangler.I never learned that much about compression and why you want high or low, but I do understand the stroke. With a long stroke, each explosion gets to drive the piston further which by nature takes longer and will result in a greater change in compression between start to finish of a stroke (explosion to exhaust). Similarly, the longer stroke will be turning a larger diameter circle/drive shaft, so even if a short and a long stroke move the drive shaft the same number of degrees, the long stroke provides more torque than the short which would be better for heavier loads.

 

BTW: I often found myself looking for 6th on my 650 and love the overdrive on my Honda V30 ... and that is only a 500cc which also redlines very high. It is a cruiser version of the old Interceptors.

 

some of those escorts had a SVO engine in em that was actually built by Yamaha for Ford Racing [I used to work at Ford] . They said 'Ford' on the cam cover but you tell by the look they were Yamahas. In fact, I saw one that said 'YAMAHA' right on the cam cover... the Yamahas were the ones that didn't blow head gaskets....

 

Maybe that was what I had ... I never blew a head gasket - my was a late one - '88

 

I almost bought one of those Ford Taurus SHO's with the Yamaha V8.

The Mass State Police had a few of them as unmarked cars patrolling the Pike between Sturbridge and Lee.

 

That's my neck of the woods I saw a trooper today sitting at the central median, but it was a standard crown vic.