LACK OF POWER IN MY 83 MAGNA V45

[frank bernardo]

HI, I JUST RECENTLY BOUGHT A 83 V45 MAGNA AND HAVE REPLACED THE TIMING CHAIN TENSIONERS.  FROM THE DAY I BOUGHT IT, IT HAS LACKED POWER.  MY NEIGHBOR SAID IT HAS LESS THAN HALF THE POWER IT SHOULD.  IT WILL REV UP TO ABOUT 6K RPM'S AND THEN HAVE A HARD TIME GOING ANY HIGHER.  I HAVE REPLACED THE FUEL FILTER, ALSO.  IT WILL GO AS HIGH AS 75MPH, BUT NO MORE.  I DID THE HIGH ALTITUDE ADJUSTMENT AS I LIVE IN COLORADO.  I AM GOING NUTS BECAUSE IT IS SUPPOSED TO BE SO FAST.  BY THE WAY, THE CHOKE SEEMS TO  BE COMPLETELY OPEN, AND THE FILTER IS TOTALLY CLEAN.  ANY TIPS WOULD BE APPRECIATED!!!

[Greg Cothern]

A bit more information would help.  Does it run good up to 6K and 75Mph?

[frank bernardo]

THE BIKE IS FAIRLY SLOW TO ACCELERATE.  IT'S JUST NOT A FAST BIKE.  I COULD HOLD THROTTLE FULLY OPEN AND EVENTUALLY GET IT TO REV UP TO 9K, BUT IT TAKES FOREVER.  THE BIKE HAS 59K MILES ON IT AND DOESNT BURN ANY OIL OR HAVE BLACK SMOKE.  CAM TIMING MARKS ARE PERFECTLY ON THE MONEY.  IT ALMOST SEEMS AS IF IT ISNT GETTING ENOUGH FUEL TO ACCELERATE PROPERLY.

[Greg Cothern]

I would start with cleaning the carbs, air filter replacement, plugs.  It should pull the RPMs up fairly quickly.  
Does it spit and sputter as you try and run it up while riding?  Any backfiring or popping through the exhaust??  Run hot?

[Curtis_Valk]

Valve timing was my first guess, but you already covered that.  Fuel would be my next and you're on track with that too.  I guess we think a lot alike.  Good luck!

Curtis

[frank bernardo]

OK, THE PLUGS ARE NEW, THE AIR FILTER IS A K&N FILTER THAT HAS BEEN CLEANED.  THE ENGINE NEITHER SPUTTERS,BACKFIRES, NOR POPS THROUGH THE EXHAUST.  BEING 25 YEARS OLD, I REMOVED THE MUFFLERS AND NOTICED NO SIGNIFICANT DIFFERENCE.  IT IDLES BEAUTIFULLY. IT REVS SLOWLY UP TO AROUND 5K RPMS.  I DIDNT EVEN NOTICE IT HAD A PROBLEM UNTIL I GOT UP TO 75MPH ON THE INTERSTATE AND NOTICED THE THROTTLE WAS FULLY OPEN.

[Greg Cothern]

Hmmmm, I come back to the timing or ignition related issue.  Sure all 4 cylinders are firing???

[frank bernardo]

ALL CYLINDERS ARE FIRING AS IT IDLES SMOOTHLY AND DOESNT SMELL LIKE RAW GAS COMING OUT OF THE EXHAUST.  TIMING IS PERFECT BECAUSE I SET IT UP THE WAY THE BOOK SAID TO AND THE TIMING MARKS ON THE CAM GEARS LINE UP CORRECTLY.  IT RUNS THE SAME WAY IT DID BEFORE I REPLACED THE CAM CHAIN TENSIONER.  IT RUNS OK, BUT I WANT TO GET THE POWER OUT OF IT THAT IT IS SUPPOSED TO HAVE.

[Greg Cothern]

Where are you located in the country??

[frank bernardo]

I AM LOCATED IN COLORADO.  I DID A HIGH ALTITUDE ADJUSTMENT AND AS I EXPECTED, NO DIFFERENCE, BECAUSE THAT IS ONLY FOR IDLE, I THINK.  
I COULD HAVE THE CARBS REBUILT BY CLASSIC IN TEXAS,BUT IM NOT CONVINCED IT'S A CARB ISSUE.  I HAVE TRIED SEAFOAM, BERRYMAN CARB CLEANER, AND SYNTHETIC FUEL INJECTOR CLEANER, ALL TO NO AVAIL.  I'M WONDERING IF THE FUEL PUMP COULD BE AT FAULT, NOT PUMPING ENOUGH FUEL TO SATISFY THE ENGINE.

[TLRam1]

Sorry to say, that could be a lot of things. In your position it comes down to a process of elimination.

May not have proper compression, either by valves not seating or rings not sealing well. If you have a compression tester you might check that.

Acts like timing is retarded. I know you have the cam lined up but not sure if the timing is fixed or adjustable pertaining to your pickup coils.

Your exhaust could be partially clogged, via rust, and you will have a great loss of power.

Still a good probability the carbs are dirty/clogged jets. Too easy to have clogged and dirty carbs. If your carbs are clean I would look at jetting.

My experience, high altitude jetting on my dirt 4 stroke bikes pertain to main jets & pilot jets/slow jets, leak jets, etc. If you are running rich the motor will not have performance. I took a trip in CO. 2 months ago. I like performance so I know when something is not quiet right.......... and it was difficult to pass a car on the highway. that is with stock jetting in my 3rd gen. Magna.  

I would call around to local Honda dealers and see if they can recommend jetting for your bike, sometimes you will get good info and sometimes bad. You will have to determine that.

What altitude are you at? I was running in 8-12,000 ft.

The more I think, the more it may be jetting. Give us more info as you check it out. Any rebuilding you should be able to do. The hardest part is getting the carbs off and putting them back on. lol

[Charles S Otwell]

My cousins V-45 had the exact same symptoms, turned out to be a couple stuck sliders with cracked diaphrams. Quick carb cleaning and a couple of good used sliders and his ran like new.

[frank bernardo]

I HAVE NEVER HEARD THE WORD SLIDERS AS PERTAINING TO CARBURETORS.  ARE YOU TALKING ABOUT THE NEEDLE JETS AND THEIR DIAPHRAMS?  I BELIEVE YOU ARE.  AS TO THE OTHER PERSONS IDEA THAT THE EXHAUST IS CLOGGED, I DID REMOVE THE MUFFLERS, AND THAT DIDNT MAKE AN APPRECIABLE DIFFEERENCE IN PERFORMANCE.  I ALSO UNDERSTAND FROM THE CLYMER BOOK THAT THE TIMING IS IN NO WAY ADJUSTABLE. I ALSO COULD DO A COMPRESSION TEST, BUT THE INSIDE OF THE ENGINE WAS SPOTLESS WHEN I CHANGED THE CAM CHAIN TENSIONER, AND IT DOESN'T BLOW ANY BLUE SMOKE.   I ALSO KNOW THAT THE PILOT JETS ARE FOR ALTERING THE MIX FOR ALTITUDE.  THE NEEDLE JET,WHICH IS THE ONE GOING THROUGH THE DIAPHRAM, IS NOT ADJUSTABLE. I APPRECIATE ALL YOU GUY'S HELP AS THIS BIKE WANTS TO SCREAM!!!

[frank bernardo]

HEY GUYS.  I JUST WANTED TO LET YOU KNOW THAT I TESTED THE FUEL PUMP AND IT IS JUST PUMPING ALL THE FUEL I NEED.  SO THAT IS ONE THING DOWN, AND MAYBE 20 MORE THINGS TO GO.

[Charles S Otwell]

You have to keep us informed as to what you find wrong, we secretly keep score when we accidently get one right! Oh come on guys you know you do!!