Go Back   Motorcycle Forum > Motorcycle.Com General Discussion > Motorcycle Mods and Maintenance

Reply
 
Thread Tools
Old 08-12-2010, 04:37 PM   #1
povertyrob
Registered Member
 
Join Date: Aug 2010
Posts: 2
Default 1984 v40 Magna clutch/transmission?

When idling in neutral with or without the clutch pulled, the bike will sometimes make an aweful grinding sound. If I have the bike on the kickstand it makes the sound more frequently. I get slipping gears in first and fourth only when im riding otherwise the other gears work and shift just fine. Neutral is a bit of a b**ch to find sometimes but it seems to shift ok..

This sounds to me like more clutch than transmission gears but I Really dont know. I didnt see any evidence of grinding when i changed the oil and took of the right hand crank case.
povertyrob is offline   Reply With Quote

Sponsored Links Remove Advertisements
Motorcycle Forum
Advertisement
Old 08-13-2010, 05:21 AM   #2
seruzawa
The Toad

 
seruzawa's Avatar
 
Join Date: Nov 2001
Location: 8501 ft.
Posts: 17,461
Default

Those old Magnas all eventually eat their trannies. It is an unavoidable occurrence due to poorly undercut gears. A tranny repair will cost upwards of $500 in parts alone. Not to mention that that Magna is one of the most difficult bikes to work on. IF you can find a shop to work on it your costs will be over $2K.. far more than the bike is worth. You MIGHT find an engine in a junkyard, however every Magna from that period eats its tranny so you are just as likely to have bad tranny.

If you want to fix it Clymer sells a good manual, however in 46 years of bike riding and having rebuilt over a dozen engines from BSAs to Kawasakis I can tell you that the Magna is the worst to work on by far. Don't waste your time. The tranny is blowing. Just junk it. Any money you put in it is down the drain.
__________________
"Make no mistake, Communism lost a big argument - one we know today as the 20th century."
seruzawa is offline   Reply With Quote
Old 08-13-2010, 05:25 AM   #3
MOKE1K
Registered Member
 
MOKE1K's Avatar
 
Join Date: Jul 2008
Location: Kalapana, Big Island
Posts: 3,994
Default

Sounds possibly like a shift fork? Seru is it the configuration that makes it a B?
__________________
"YOU CAN'T BOLT ON SKILL"
MOKE1K is offline   Reply With Quote
Old 08-13-2010, 05:44 AM   #4
seruzawa
The Toad

 
seruzawa's Avatar
 
Join Date: Nov 2001
Location: 8501 ft.
Posts: 17,461
Default

Quote:
Originally Posted by MOKE1K View Post
Sounds possibly like a shift fork? Seru is it the configuration that makes it a B?
No, not just a shift fork. The poorly made gears put lateral force on the forks. Usually 2nd,3rd and 4th gears and the two forks go. Honda sold an upgrade "kit" which was a new gear IIRC, but they never recalled the bike. Just gave the owners a big FU.

The bike is stuffed together like nothing I've ever seen. Literally you have to take the rear wheel off just to change the fuel filter. The first time I pulled an engine it took me longer than pulling a car engine. You have to experience it to believe it. Then there's setting the cams when you put it back together... shudder. Then when you finally do get it running it runs really really hot due to the inadequate radiator. Look at a picture and you'll see how small the radiator is. The rear cylinders radiated as much heat in the summer as my Shovelhead did. I ended up removing the thermostat and putting a switch in the fan circuit to run the fan constantly in summer. The fan doesn't come on until the temperature gauge is nearly to the top. Two different engines did the same thing.

For me the early Magna destroyed any reputation Honda had. That Honda would foist such a horrible POS on the public was a crime. It really was a terrible motorcycle. I haven't yet discussed the sponge soft suspension or the worthless anti-dive valve in the fork. A Sportster will easily out-handle an early Magna. Run, don't walk away from the Magna.
__________________
"Make no mistake, Communism lost a big argument - one we know today as the 20th century."

Last edited by seruzawa : 08-13-2010 at 06:03 AM.
seruzawa is offline   Reply With Quote
Old 08-13-2010, 08:15 AM   #5
sarnali2
Aging Cafe` Racer

 
sarnali2's Avatar
 
Join Date: Jun 2007
Location: Sittin' down by my window, lookin' at the rain.
Posts: 8,719
Default

My 84 V65 Sabre was pretty much the same thing, though I didn't delve into it anywhere near the extent Seruzawa did. Routine maintenance like valves and the afore mentioned fuel filter were bad enough, coupled with hot running and electrical meltdowns. A fun bike when it ran but not something I'd choose again.
__________________
"Carpe` Throttelum -Loud Suits Save Lives"

"He said he's farting because of his medication"...
sarnali2 is offline   Reply With Quote
Old 08-13-2010, 10:41 AM   #6
povertyrob
Registered Member
 
Join Date: Aug 2010
Posts: 2
Default clutch basket

I had an old mechanic briefly take a listen to it and he seems to think it may be in the clutch basket. Could the clutch basket cause those problems as well?
povertyrob is offline   Reply With Quote
Old 08-13-2010, 10:55 AM   #7
seruzawa
The Toad

 
seruzawa's Avatar
 
Join Date: Nov 2001
Location: 8501 ft.
Posts: 17,461
Default

Quote:
Originally Posted by povertyrob View Post
I had an old mechanic briefly take a listen to it and he seems to think it may be in the clutch basket. Could the clutch basket cause those problems as well?

You can pull off the right side engine cover without a lot of trouble and look at it. The basket might cause weird noises I guess but it will have nothing to do with the bike slipping in only two gears. Clutch problems would show up in every gear.

I wish I could give you better news, but those Magnas are notorious for eating their trannies. Camshafts too.
__________________
"Make no mistake, Communism lost a big argument - one we know today as the 20th century."
seruzawa is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off