2nd gear 70mph, 5th gear 75mph?

[Ga Dawg]

Does anyone know what would cause an '87 VR to red line in 2nd gear at 65 mph but not get above 4500rpm and 75 mph in 5th gear. It does sputter a little around 6000 rpm but will recover up to the red line. I normally don't do this to the engine but was trying to blow out the jets in the carbs after 2 cans of Sea Foam run through her this past year. It runs great but just a little slugesh in high gear. Any insight would be great and I just got carbs sync. this weekend. Is this normal? THANKS!!!

[MiCarl]

It's not normal (unless you're going up a steep hill, strong headwind, lots of weight).

 

Almost certainly fuel system. Most likely carburetors. The fact that you are trying to "blow out" your jets is a pretty good indication that you know of a carburetor problem.

[pegscraper]

Carburetor slides that are stuck closed would cause these symptoms.

[Ga Dawg]

I had replaced the diaphrams recently. What would cause those slides to stick? What should I do? Thanks!

[pegscraper]

Well, you about have to remove the slides to replace the diaphragms, so that may not be it. Did you verify that they were still free when you put everything back together?

[massey130]

did it run this way before u replaced the diaphragms?

if not, check your work. may be self inflicted.

just one of the many possibilities.

[Rocket]

did it run this way before u replaced the diaphragms?

if not, check your work. may be self inflicted.

just one of the many possibilities.

 

Probably a re-sync is needed, since the diaphram change & also check the plugs for fouling. Sounds like your running on 3 cylinders, as you should hit 75 mph in 2nd gear & at least 110 in 5th, with throttle to spare.

 

[Yammer Dan]

Just a thought. Fuel filter???

[SC89Venture]

Just another thought from an extreme newbie, could it be your air filter is clogged? I just changed mine, it was a foam type filter, looked home made. It appeared to be clogged, could not see any daylight from inside out. Tossed it for an original one.

[Ga Dawg]

I am going to replace fuel filter, air filter,and plugs. Also, I will check the slides to make sure they are not stuck. When they do stick what is the best way to unstick? Carb cleaner?

Thanks!!

[rjg1985]

Check the compression while you have the plugs out. My 85 has a week #2 cylinder and will do over 90 mph easily in fifth gear.

[BradT]

I am going to replace fuel filter, air filter,and plugs. Also, I will check the slides to make sure they are not stuck. When they do stick what is the best way to unstick? Carb cleaner?

Thanks!!

 

Take a close look at each plug when it comes out and make sure you remember what one come from which cylinder.

 

Spark plugs can really tell alot about how the engine is running.

 

Brad

[warthogcrewchief]

I had the same problem... Turns out one cylinder wasn't firing. I checked the TCI, checked the coils, checked the spark plug wires (changed them out anyways), and it finally turned out to be a bad spark plug...even though I had replaced it four months prior (while I was doing the rebuild). After that, she ran on the highway great despite a minor carb issue that I'm working out...waiting on parts!

[Ga Dawg]

Thanks I will let yall (from the south) know how it goes. Thanks for the ideas!

[Snaggletooth]

Yep, these bikes run surprisingly well on 3 cylinders. Some have been surprised to find out they had a cylinder not firing due to a bad plug, poor wire or a messed up carb. And I'll say from personal experience that if it's only firing on 3 it's tough to get it up to 95. Once you resolve the issue you're back in the 110 club.

[DblTrbl]

Probably a re-sync is needed, since the diaphram change & also check the plugs for fouling. Sounds like your running on 3 cylinders, as you should hit 75 mph in 2nd gear & at least 110 in 5th, with throttle to spare.

 

 

75mph in 2nd and 110 in 3rd? Seriously? I have an '09 and I don't believe it will do those numbers, but then again, I never tried.

[camos]

75mph in 2nd and 110 in 3rd? Seriously? I have an '09 and I don't believe it will do those numbers, but then again, I never tried.

Did you not notice, this is the First Gen forum?

Couldn't resist.

[Venturous Randy]

75mph in 2nd and 110 in 3rd? Seriously? I have an '09 and I don't believe it will do those numbers, but then again, I never tried.

 

That was 110 in 5th, not 3rd.

Randy

[Yammer Dan]

But it is possible to go over 100 mph in 3rd!! How far over?? I know. All ya gotta do to find out........

[DblTrbl]

That was 110 in 5th, not 3rd.

Randy

 

sorry, my bad....110 in 5th...got it, but 75 in 2nd? That's winding it up!!

[videoarizona]

I scare myself when I go over 90 in 3rd. She is pulling so strong, I don't want to shift!

Great motor!