Topic: 76 550 top gear rev problem

[FIREBLADE74]

No clear test but the float are set to 22mm, which I verified twice already.

As for the petcock, I didn't do anything to.

What are the plugs saying?
Dirty tank?
Poor fuel delivery?

[evinrude7]

side question.  when you all do clear tube is it preferred on the bike or on the bench?  no diff?

[FIREBLADE74]

Bet! Thx calj.

What fuel lines do you suggest? Not for the clear test. Auto parts store doesn't have metric lines.

[DaveBarbier]

Next time just take a picture of all the plugs in one shot lined up 1-4 left to right.

What throttle position were you at? Jets are not RPM dependent. It has to do with slide opening, not RPM.

[DaveBarbier]

side question.  when you all do clear tube is it preferred on the bike or on the bench?  no diff?

It's easier to adjust the floats if you need to while it's on the bench.

[evinrude7]

Thank you sir

Sent from my LG-D850 using Tapatalk

[FIREBLADE74]

Next time just take a picture of all the plugs in one shot lined up 1-4 left to right.

What throttle position were you at? Jets are not RPM dependent. It has to do with slide opening, not RPM.

Will do on the pics but I wanted y'all to see the crazy discoloration.

I was at the stop throttle wise. Then I hit the kill switch and clutch.

I'm gonna reroute my fuel lines. Right now I have them sweeping over the top of the pods instead of coming thru the holes the lines came thru stock.

[turboed13b]

Air screw isn't going to do anything on top end. Set it and leave it.

Make sure boot clamps are tight first. Try raising the needles one notch. If that doesn't work jet up.

[FIREBLADE74]

Ok, problem 1!

Make sure your carbs are fully seated in the rubber boot, mine were partially on.

Noticeable pickup! Doing another chop, I'm thinking my plugs should show it being rich since my air mixture is 1.25. Notice hesitation in the low rpm range could be flooding.

I may need to resync carbs since they were synced with the half azz carb install??

[FIREBLADE74]

Plugs look nice and toasty.

I found that my exhaust was seriously loose, bolts backed out. This maybe the source for the hesitation.

Calj, what do you think?

[DaveBarbier]

Remember that the mixture screws only affect idle. I don't want you to think that they are an overall adjustment. Normally, you want to do a plug chop idling with a box fan on the headers for like 5 minutes. Then go to a chop at wide open throttle (while riding) and then work down (3/4, 1/2, 1/4, etc)

Glad there was an obvious issue, that's always nice to find. Hopefully it's a lot closer.

[FIREBLADE74]

Dave,

It looks good so far! I'm going to tighten up that exhaust and sync again.

But in all actuality I think I'm expecting too much from this bike, lol.

[BomberMann650]

50-ish hp can be a lot of fun if ya know how to use it!
Even the professionals take corners at 35mph.

Exhaust leaks suck

[FIREBLADE74]

50-ish hp can be a lot of fun if ya know how to use it!
Even the professionals take corners at 35mph.

Exhaust leaks suck

Its fun but coming from a 1000cc bike, it feels like something is wrong, lol.

[BomberMann650]

These were smooth running motors for the time.  Salesmen would balance coins on the fins of a running motor.  If the points timing and vacuum sync are off, it will run rough.

I've been passed by liter bikes like I was standing still..  even at 4th gear redline (85mph-ish)

[FIREBLADE74]

These were smooth running motors for the time.  Salesmen would balance coins on the fins of a running motor.  If the points timing and vacuum sync are off, it will run rough.

I've been passed by liter bikes like I was standing still..  even at 4th gear redline (85mph-ish)

Lol, they will haul azz!!

[RAFster122s]

It never is going to have the acceleration or speed of a Liter bike... It is the audio and the feedback the bike gives you is so much different than a modern bike. Their aesthetics are what draw many to them. They have a lot of character and soul. The Carbs are more of an auditory thing when not in an airbox as well as the tappets and chain and the general exhaust note is so much different. Exhaust being easily changed...  The big bikes and the sport bikes are like riding a rocket sometimes.  Not quite Busa level but they do not slouch in any regard.

If you are coming off a Fireblade Liter bike it has what 120hp? or more?  I have no idea...just a swag. 

Sometimes going slower can be fun...especially when you are with bikes of similar limited hp and are dicing it up on a track. You don't have to go fast to have fun.  Sometimes even going slow you have time to look around and enjoy the experience.  It is that way on a 70cc Passport.  You are only going to be going 35-40mph and in city traffic drivers are gonna hate you but out away from city traffic where you don't have that pushed feeling behind you, you can enjoy the ride and have more time to scan the surroundings if there isn't much traffic. TOTALLY DIFFERENT experience than zooming down the road.

The small bikes around 100-150cc, old vintage bikes, are often called Tiddlers and lots of folks in the NE love to get together for Giros with them and just out for a fun ride together. They can be lots of fun. 

The guys on their sport bikes blasting down the road at 100-120 to 160 or so are there for the thrill and they are really a risk to themselves and their fellow riders as things happen so fast at those speeds. Naturally you are not operating your bike at those speeds in heavy traffic.  You aren't making videos to show on the net of your bike doing 200km/h or 120-160 in traffic like some duffus' in Ontario and the like that the police decide to track down and prosecute.
Or acting like the hooligans in gangs of riders stunting on the highways in large packs of riders and basically running roughshod over any laws and traffic by sheer numbers and disregarding all laws depending upon the numbers overwhelming the police's ability to arrest them.  That some of their group will fall victim and you will laugh about it....
 

[FIREBLADE74]

So true!

I do enjoy the low power, especially on those back roads. It seems that you can look around more be more relaxed but on that blade it wants to go fast and that's actually where it likes to be, slow riding it does not like, handling suffers.

I'm going to tighten this exhaust, adjust this clutch and ride it like I stole

[BomberMann650]

You gotta match pace with the old girl.

[FIREBLADE74]

Ok the more I work on this bike the easier it becomes and the more I notice that user error/ignorance is the cause of most problems.

So I'm thinking of replacing my caps with some NGKs since mine look like the originals and the studs were all rusted looking. While researching for the best I ran across an installation thread, on here I believe, that said the caps are to be twisted on, causing the wires to wrap around the stud. WOW!!!

I've been fanning out the wires to create a hole in the center and just pushing the caps on until they stop. I expect weak spark from this.

So I just went out and refanned the wires, this time twisting the caps on. What a world of difference, my idle is smooth as hell and it seems that my low rpm stutter is gone when I rev it, not under load tho.

When the new caps come in I expect this baby to run like a scalded dog, maybe a hit dog, lol.

Cant ride it due to tstorm but I'm thinking my problems are almost over. Now if I can just get this running tail light situated.

[TwoTired]

Count the number of teeth on the chain sprockets.

Check the carbs for main jets laying in the bottom of the bowl and no jet retainer springs.

And look for corrosion around the main jet holders ruining the seal of the jet orings.

Check for clean emulsifier tubes in all the carbs.

Compression numbers would be helpful info.

When passing, downshift 1 or 2 before throttle twist.

[FIREBLADE74]

Alls good except I never counted the teeth.

[BomberMann650]

Too bad you can't try a run on the butt dyno now that you realized the trick with the plug caps!

[FIREBLADE74]

Too bad you can't try a run on the butt dyno now that you realized the trick with the plug caps!

I'm on it soon as I get off tomorrow, and that's a fact lol.

[RAFster122s]

If that has not fixed it, you should check your petcock for flow.  If it is not the one year only original a few have found the clone petcocks to have smaller internals on occasion and it slowed fuel delivery.  But, I would expect you to see this problem on higher gears at or near, or before you reach redline in those gears.
If your plug caps do not fix it, then I would see what the clear tube test shows and see the volume of fuel given by petcock in a timed period.
Running smaller fuel line can restrict your flow volume as well. 

Lloyd's advice is very sage wisdom, definitely things to investigate when looking to have max performance.

Welcome back TT, I am happy to see you here again!

David