why does this happen?

[jabberjoe87]

my 77 750 has a stutter at about 7000 rpms. When i crank on the throttle its all good screaming wide open, then when it hits about the 7 zone it hesitates and doesn't want to go higher. Any ideas on what is causing this? Thanks.

[chef1366]

Ignition or the main jet is too small.
Does it surge or pop when hitting the wall?

[yasser]

my 77 750 has a stutter at about 7000 rpms. When i crank on the throttle its all good screaming wide open, then when it hits about the 7 zone it hesitates and doesn't want to go higher. Any ideas on what is causing this? Thanks.

That's a lot 7s maybe it's a bad luck thing.

[jabberjoe87]

its more of a surge and it hesitates. and throughout all other rpm ranges its fine, just when it gets up to about 7 it does this. This is alot of sevens by the way

[earlfor]

My first guess is the valves need to be checked/adjusted.
2nd guess is ignition timing.

Earl

[nisom512]

I had the same problem but went away after I redid my carbs the right way and with o-rings on intake boots and in carbs.

good luck
Jake

[850 Combat]

I had this problem on a bike when the points were not opening up far enough. Have you checked them?

[skidMarkNZ]

I had the same problem but went away after I redid my carbs the right way and with o-rings on intake boots and in carbs.

good luck
Jake

Yep my intake boots were torn, fixed them and problem is gone, and it pulls harder than chuck norris.

[jabberjoe87]

i just adjusted my valves, but havent tuned the carbs after the adjustment except for the idle as they seemed fine, until high rpms that is. I havent checked my points in a little over a year.

[earlfor]

i just adjusted my valves, but havent tuned the carbs after the adjustment except for the idle as they seemed fine, until high rpms that is. I havent checked my points in a little over a year.

Then, the first thing I would check is the condition of the points surfaces, gap, and timing.
Set the point gaps to 14 thou at their widest and set the timing with a strobe timing light.
Check the timing twice, once for the left side point set using the 1 or 4 plug and then the right side point set using the 2 or 3 plug.

Earl

[jabberjoe87]

thanks for your help everyone

[jabberjoe87]

so i checked my points the other day and they are fine, i never mentioned in the thread that i jetted it have a 4-1 and have pods, my main jets are 110's i'm thinkin i need to try putting 115's in as the same surging happens right at about 7000 when the mains should be kickin in anyway. I want to fix this problem as the 1000 motor probably isn't going to go in until a real rainy week or its cold.

[tkent02]

so i checked my points the other day and they are fine, i never mentioned in the thread that i jetted it have a 4-1 and have pods, my main jets are 110's i'm thinkin i need to try putting 115's in as the same surging happens right at about 7000 when the mains should be kickin in anyway. I want to fix this problem as the 1000 motor probably isn't going to go in until a real rainy week or its cold.

Those mains are way too small.

[TheCafeKid]

Those mains are way too small.

Yah...

Some guys say they're running fine with a pipe and pods at 115...I had 115s in my 77 750, wouldnt pull worth a crap above 7K...125s or 127.5s are where I suggest you go...Needle in the 2nd clip from the bottom.