Scooter won't go past 6000 RPM when riding By t84a (Read 14,982 times)

[t84a]

Exactly what studs are we measuring?

[dmartin95]

Your cylinder stud spacing...

IMO, a  57mm b case is a way better motor and highly sought after... An a case you can only bore up 63mm, a b-case you can bore up to 67mm, add a +8.5 stroker and you got a screaming 232cc that is a torque monster.

[Alleyoop]

Jan 17, 2015 20:30:14 GMT -6 Alleyoop said:

Jan 17, 2015 19:47:16 GMT -6 t84a said:

This one?

Measure the studs center to center criss cross that looks like a B case to me and not your A case motors like your 157s
Alleyoop

What did I say earlier, and it does not have to have a 61 piston by the way it could be different size with a stroker crank. But we will not know until he measures spaceing of the studs: Also it could just be a different head in which case it has the rockers are longer due to the valves being longer as well.

[JR]

tvnacman,dmartin95,t84a,Alleyoop,jerryscript Bashan


One it is the right thing to do and move on when this is someone else's thread. If either of the two that are at odds here have a some helpful information about the subject at hand for the OP by all means let's help him, otherwise the arguments of what was/is that don't pertain to the thread subject material need to be discussed via PM or another thread.

JR

[Bashan]

Ok, I talked to Jack and I was going to lock the thread. However, Jack pointed out that the "debate" didn't involve the original poster. Therefore, it wouldn't be fair to him to lock his thread because of others. I went through and deleted the contentious posts as they didn't have anything to do with the thread's topics. This was my call so if you want to be upset with somebody blame me. The thread that was started on the Anything Goes board was deleted by Cyborg. We discussed moving questionable threads out of sight in the future but for that one, it's toast. Rich

[Alleyoop]

[JoeyBee]

It's a warm day, why waste it? Let's ride.

[t84a]

Update:

Received my jets and rollers today. Pulled the carb-it had a 107 MAIN. Switched to 120. Took it out for a ride-no real noticeable difference. Switched the rollers to 11g-still maxes out at 6k. I do like the lighter rollers though because it puts me at a higher RPM earlier. I'm pretty sure 120 is too big. I'm going to put a 115 in. So there it is-pretty much what I expected. Hopefully it will loosen up a bit and the gauges could be wrong as well. I'll continue to update as I tweak. Thanks for the replies.

[tvnacman]

How does the engine sound ? Just outside the box thinking , could you tack be off ?

John

[jomama0867]

t84a, for the record I share your frustrations! I, too, have a problem getting above 6000 rpm's (except for a very rare occasion when I'm WOT on the highway at 3:30 in the morning . . . alone), and after almost a year of riding my 150cc (157qmj) I have come to the conclusion that "there ain't necessarily nuthin wrong with 6000 rpm's". After spending all kinds of time, money and sleepless nights "worrying" about my "low" rpm's, I didn't remember why I bought the thing in the first place . . . to ENJOY! I guess my point is that if some day by some miracle mine starts to hit 7500-8000 rpm's, I'll try to find the change and let you know. Otherwise IMHO, as long as it's performing to your satisfaction, don't worry about "details" and ENJOY THE RIDE!!!

[rks]

I think tvnacman is on to something. I can't picture jomama0867 being content with a 150, that only turned 6000 rpm's. My 157qmj, at 6000, is right around 46 mph, but that's with 14 gram sliders in the variator. If you have a more standard 11 or 12 gram roller (mine came with 10.5), you wouldn't be getting but 40 mph or so at 6000 revs. Wouldn't be many happy 150cc owners, if they all maxed out at 40 mph.

Think your tach is off.

[Alleyoop]

In the Video it was not revving high, from the sound I would say 6K+ but no were near 7K or +.
And his weights are 13 gram weights worn down to 12.8 12.9 grams. So his rpms will be low. On my 157QMJ if I put in 13gram weights it will only rev to little over 6K and no more.

Also since it is a different motor and the Cam Sprocket is different it may have a long duration cam which will lower the rpms and give lots of low end torque but no high rpms for top end.
Alleyoop

[rks]

I should have quoted jomama0867's post, for it was his lack of revs I was addressing. If drivetrain is unaltered, don't see how he'd be getting more than 40 mph out of it. I'm very happy cruising around at 40, but wouldn't be if that was all my 150 had to give.

Alley, if you are talking about your 350 pound trike, with those tall gears in the tranny, I can fully understand why it won't rev beyond 6k with heavy weights in the variator.

Now my 239 pound scooter, with it's stock 157qmj (except a 115 main jet, and K&N airfilter), and standard tranny gears, has no problem exceeding 7k with 14 gram sliders.

[Alleyoop]

Well it is all the way you have it all setup, mine hits 50mph and it is at 5200 at 60mph it is cranking only 6200, talk about a sweet trike pulling 350 plus my 180 at such low rpms. Stock it needed 8K+ to only go 50mph.

[jomama0867]

You tell 'em, Alley! For the record, my scoot hits 55mph (gps verified) @ 6200 rpm's, so my point is that if I can hit that speed without 7500 revs, what's wrong with that? Sure I'm a novice, but to me lower revs HAS to be some kind of advantage wear-wise . . . right?