Total Motorcycle Community Forums

My question is --is it normal--the engine will tac 7,000 or higher if I want in first 3 gears and will only tac up to 6,000 in 4th and 5th--then overdrive--haven't gone over 5,000 in od cause then I would breaking the speed laws. 1984 honda vf500c magna v30 is my ride.

Thank's to this forum and all of you that take your time to help.

Well, it's a V4 engine, and this is your tach here:



So it looks like it should be hitting the higher than 7k rpm on all gears, if it isn't (like the RPM needle is just bouncing off the 7, 6 or 5k RPM then I suspect your carbs need tuning as the jets and/or needle may need replacement.). You might get lucky and the carbs are just out of tune.

Mike

The first thing I would do is try some Seafoam® in your gas and see if that helps.

totalmotorcycle wrote:Well, it's a V4 engine, and this is your tach here:



So it looks like it should be hitting the higher than 7k rpm on all gears, if it isn't (like the RPM needle is just bouncing off the 7, 6 or 5k RPM then I suspect your carbs need tuning as the jets and/or needle may need replacement.). You might get lucky and the carbs are just out of tune.

Mike

Thank you--by needle do you mean the slide needle--I have just taken off all the carbs
--cleaned them by boiling in a lemon juice-water mix last week--new boots--the slide needles were dirty as the rest--all cleaned up good. I know the main jets are diff in the two front carbs--diff hole arrangement is what I noticed--if I did mix these and put them in the wrong carb--what kind of problem would this cause??
I bench syn the carbs and will be using my manometer to fine tune as soon as my tubes come in--
(brass tubes for syn tool--mine took a walk years ago so had to order new ones)
If I did mix the main jets and put them in the wrong carbs can you tell me the proper way--the two front carbs are down draft? and the two rear are side draft? as I said the only diff to my eye is the holes in the jet are in a different pattern. Mabe you can describe the hole pattern for main jets and confirm that I am right about the two front carbs are downdraft and the two rear are side draft--I could have that backward too.

Thank you.

I just bought this bike a few weeks ago so don't know how it was running--since the seller told me the bike sat in his garage for 5 years I got busy on the carbs before any real high speed testing--so I don't know if this rpm issue existed prior to carb clean (possible screwup) with main jets.
What puzzels me is the engine will red line-if I wanted in first gear and--second gear----then in third and 4th gear only 6,000---????
problem solved--I used regular fuel hose to replace preformed fuel hose---don't work because when the hose needs to bend it partially colapses and restricks fuel flow so when I get to 50 or 60mph the engine is starving for gas--so I installed brass 90's at bend points---wala.

i