Author Topic: ‘78 Convert weaknesses  (Read 948 times)

Online dxhall

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 1156
‘78 Convert weaknesses
« on: January 06, 2020, 03:45:22 PM »
Against my better judgment and without my wife’s knowledge, I purchased a ‘78 Convert last weekend.  It should arrive here next week.

It supposedly has only 4000 miles.  Other than the purple Fat Bob tank and fenders, it seems to be stock.  How could I go wrong?

Is there anything I should be concerned about with a low-mileage ‘78?  I think ‘78s have the later (good) flywheel, but I’m not sure about the rest of the drivetrain.

Offline TOMB

  • Guzzi Hero
  • *****
  • Posts: 1297
  • Location: Newington Ct. 06111
Re: ‘78 Convert weaknesses
« Reply #1 on: January 06, 2020, 03:54:26 PM »
Also the front forks have the extra spring  so it sits a little higher 1 1/2 " +-, may have or not updated switches (think T3 style old G5 style new).
May have the police style bars  or flat style like some T3 had.

I have a 78 vert in my shed so i can take pics if you need any pics for reference  ,24000 miles

TOMB
TOMB

CENTRAL CONNECTICUT
1972 Eldorado new to me so "0" miles so far
1972 AMBASSADOR 169000 MILES
1978 G5 170000 MILES
1973 V7 SPORT 25000 MILES
1973 ELDORADO 300000+ MILES
1980 CX100 50 MILES
1976 CONVERT-62000 MILES AND BUILDING
1976 HONDA CB400F 27 MILES AND BUILDING SOLD

MGNOC # 2723

Online fotoguzzi

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 18998
  • vee git tooh soon oldt und too late wise -my Dad
Re: ‘78 Convert weaknesses
« Reply #2 on: January 06, 2020, 06:12:22 PM »
Score! Let's see the pics.
MINNEAPOLIS, MN

Online brider

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • Posts: 1081
Re: ‘78 Convert weaknesses
« Reply #3 on: January 06, 2020, 08:44:39 PM »
Score is right! Nice Christmas present!
'85 Cal II Auto
'86 LM IV (sold)
'71 Ambo project
Wish'd I'd never sold:
'72 Red Eldo
'74 White Eldo LAPD
'77 Convert with DB bags
'06 Gas Gas EC300

Wildgoose Chase Moto Guzzi

Re: ‘78 Convert weaknesses
« Reply #3 on: January 06, 2020, 08:44:39 PM »

Online Rich A

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 3109
Re: ‘78 Convert weaknesses
« Reply #4 on: January 06, 2020, 08:54:10 PM »
You might want to check the brake hoses.

Rich A

Online fotoguzzi

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 18998
  • vee git tooh soon oldt und too late wise -my Dad
Re: ‘78 Convert weaknesses
« Reply #5 on: January 06, 2020, 09:41:32 PM »
You might want to check the brake hoses.

Rich A
and go over the whole charging system..
MINNEAPOLIS, MN

Online Antietam Classic Cycle

  • Guzzi Hero
  • *****
  • *
  • *
  • Posts: 12303
  • Happily stuck in the past.
    • Antietam Classic Cycle
  • Location: Rohrersville, Maryland
Re: ‘78 Convert weaknesses
« Reply #6 on: January 06, 2020, 09:57:44 PM »
You might want to check the brake hoses.

Rich A

I replaced every hose on my '76 - brake, breather, oil line to heads and especially the transmission hoses. All of the them really need to be replaced if they're the originals.
Charlie

Offline TN Mark

  • Guzzi Mentor
  • ****
  • Posts: 603
Re: ‘78 Convert weaknesses
« Reply #7 on: January 06, 2020, 10:07:30 PM »
I had a 77, a 78 and either a 79 or an 80 Convert. They were awesome motorcycles and a lot of fun. I think it was the 79 or 80 that broke the flywheel right at 10K miles. As long as you accept it for what it is you should have years of enjoyment from it. Just don’t expect any real ‘performance’. Like I said, accept it for what it is and enjoy it for years. If you can find a Vetter fairing for it, you’ll love that as well. They really go together well.

If it still has the oem electric petcock, you may want to keep an eye on it. After all these years and such low miles, you should go completely through it front to back. Also, don’t trust the original rubber transmission hoses either. They’re likely rock hard by now. As is any of the other oem rubber parts and seals.

Online dxhall

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 1156
Re: ‘78 Convert weaknesses
« Reply #8 on: January 06, 2020, 10:13:16 PM »
Is there ever a problem with the torque converter overheating?  If I am replacing hoses, now would be the time to upgrade.

Offline Yeahoo Whoyah

  • Guzzi Hero
  • *****
  • *
  • Posts: 1174
  • 1971 LAPD Ambassador - 1976 Convert
  • Location: El Dorado Hills California
Re: ‘78 Convert weaknesses
« Reply #9 on: January 07, 2020, 01:39:14 AM »
In addition to what others have said about replacing hoses and oil lines, another big improvement is converting the dash lights to LED. The stock incandescent bulbs do a poor job particularly in direct sunlight.  Greg Bender sells a rectifier to fuse panel wire (with resistor) required to bootstrap the charging system when changing the "Gen" lightbulb to LED.

http://www.thisoldtractor.com/moto_guzzi_tonti_dash_indicator_light_improvement.html

https://wildguzzi.com/forum/index.php?topic=82243.0

http://www.thisoldtractor.com/for_sale/wiring_subharness_tonti_rect_bootstrap_1.jpg
Greg Tillitson
El Dorado Hills Calif.

Online brider

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • Posts: 1081
Re: ‘78 Convert weaknesses
« Reply #10 on: January 07, 2020, 08:20:41 AM »
Is there ever a problem with the torque converter overheating?  If I am replacing hoses, now would be the time to upgrade.

I don't think there's any history of the TC overheating, except for trapped fluid when the dreaded pump-drive hex shaft fails, which is (1) of (2) major failure potentials with the Convert.

Didn't search your history, but didn't you own a Convert previously? Your name looks familiar as a Convert discuss-ee.

This always seems to spark another long Convert drivetrain discussion, but here goes:

1. Check thru the timing hole on the right-side of the bellhousing with a flashlight to see if the flywheel is a cast aluminum(? "heavier") flywheel, or if it's a thinner, steel flywheel. STEEL FLYWHEEL WILL FAIL....MINE DID @ ~15K MILES. Heavier flywheel, you're good to go!

2. In the front timing cover, there's an ATF pump driven by a steel 6mm hex-shaft, extremely similar to a section of 6mm allen wrench. Guzziology has an extensive write-up on this, but both of my Autos rounded-off the hexes @ ~20k miles, leaving you dead on the road and fluid within the TC cooking as you give it more throttle wondering why the engine is revving but you're slowing down. At 4k miles, I wouldn't hesitate riding it another 6-8k more miles, but it's fairly easy to pull the timing cover off; the hex shaft is then right there to inspect and replace with a hardened shaft (various methods to make/obtain that, search here).

While you're in the timing cover, there's a replaceable seal and large o-ring in the pump itself. At ~35k miles mine started to slip AGAIN, as if the hex had rounded off AGAIN, but it turned out to this hardened, old large o-ring in the pump.

DO NOT be scared by this talk of failures; at 4k, just ride the bike now and fall in love; the eventual repairs won't seem so bad once you love the bike.
'85 Cal II Auto
'86 LM IV (sold)
'71 Ambo project
Wish'd I'd never sold:
'72 Red Eldo
'74 White Eldo LAPD
'77 Convert with DB bags
'06 Gas Gas EC300

Online Antietam Classic Cycle

  • Guzzi Hero
  • *****
  • *
  • *
  • Posts: 12303
  • Happily stuck in the past.
    • Antietam Classic Cycle
  • Location: Rohrersville, Maryland
Re: ‘78 Convert weaknesses
« Reply #11 on: January 07, 2020, 08:36:02 AM »
In addition to what others have said about replacing hoses and oil lines, another big improvement is converting the dash lights to LED. The stock incandescent bulbs do a poor job particularly in direct sunlight.  Greg Bender sells a rectifier to fuse panel wire (with resistor) required to bootstrap the charging system when changing the "Gen" lightbulb to LED.

http://www.thisoldtractor.com/moto_guzzi_tonti_dash_indicator_light_improvement.html

https://wildguzzi.com/forum/index.php?topic=82243.0

http://www.thisoldtractor.com/for_sale/wiring_subharness_tonti_rect_bootstrap_1.jpg

I would go farther than just the dash lights in LED. The Convert really benefits by going all LED - headlight, taillight and signals. An LED headlight in particular helps keep the battery charged. 
Charlie

Online chuck peterson

  • Guzzi Hero
  • *****
  • *
  • Posts: 4476
  • Location: New Haven CT
Re: ‘78 Convert weaknesses
« Reply #12 on: January 07, 2020, 08:49:15 AM »
I use to complain about the occasional repairs, mostly electrical. Then I realized I was putting down massive mileages like never before...of course it's gonna need attention. With a decent comfortable seat and a windjammer or shield out front, your going to be gone, a lot.

It's a Barco lounger on wheels.

Beat on it it gets better regarding Rpms. I preferred low range for everything except flat out hiway. At about 55-60 in low it'll sound like it's ready to grenade...not. Push thru and you'll be surprised how it can lift its skirt 55-75 in low range.

With my amateur mechanics and Guzziology, most fun touring I've ever had.
Congrats!

Photos!
"I'd like to thank all my friends who have kept my Guzzi's going, but mostly...TOMB."
150k on Verts
750 Nevada
400f
R5 Yammie
BV250
4x 1976 Moto Demm Smily,, now 5, oops now 6, oops now 7
1980 SP1000 in little bits and pieces

Online brider

  • Guzzi Hero
  • *****
  • *
  • *
  • *
  • Posts: 1081
Re: ‘78 Convert weaknesses
« Reply #13 on: January 07, 2020, 09:18:48 AM »
At about 55-60 in low it'll sound like it's ready to grenade...not. Push thru and you'll be surprised how it can lift its skirt 55-75 in low range.

This has always surprised me, and I have never been past ~50 because of the sound of an impending grenade. Next time I'm out I may try to get 'er to lift her skirt (I like that metaphor!).

Edit: Couldn't stand it, so I finally did the math using the final drive ratios, rear drive ratio, wheel size, and estimated tire size, INCLUDING the 1.1 slip ratio reported in the Guzzi literature.

1st gear @ 70 MPH - 6,100 rpm
2nd gear @ 90 PMH - 5,865 rpm

Amazing! I've done 90 before, and the motor doesn't sound like it's going to grenade, must just be the wind noise that drowns it out. 6,100 rpm surely isn't near redline, so I'll fer sher give it a try and see how lively it feels in 1st gear!
« Last Edit: January 07, 2020, 09:44:04 AM by brider »
'85 Cal II Auto
'86 LM IV (sold)
'71 Ambo project
Wish'd I'd never sold:
'72 Red Eldo
'74 White Eldo LAPD
'77 Convert with DB bags
'06 Gas Gas EC300

Online chuck peterson

  • Guzzi Hero
  • *****
  • *
  • Posts: 4476
  • Location: New Haven CT
Re: ‘78 Convert weaknesses
« Reply #14 on: January 07, 2020, 03:04:11 PM »
6100 at 70 mph in low range! That sure solves alot of charging issues..!
5850 at 90 in high?

Those numbers confirm what ive always felt about them. Your only at 2/3rds power, Scotty! Give it all you’ve got!

"I'd like to thank all my friends who have kept my Guzzi's going, but mostly...TOMB."
150k on Verts
750 Nevada
400f
R5 Yammie
BV250
4x 1976 Moto Demm Smily,, now 5, oops now 6, oops now 7
1980 SP1000 in little bits and pieces

Offline TOMB

  • Guzzi Hero
  • *****
  • Posts: 1297
  • Location: Newington Ct. 06111
Re: ‘78 Convert weaknesses
« Reply #15 on: January 07, 2020, 03:26:44 PM »




Here's mine.
1976-60,000 miles
TOMB
TOMB

CENTRAL CONNECTICUT
1972 Eldorado new to me so "0" miles so far
1972 AMBASSADOR 169000 MILES
1978 G5 170000 MILES
1973 V7 SPORT 25000 MILES
1973 ELDORADO 300000+ MILES
1980 CX100 50 MILES
1976 CONVERT-62000 MILES AND BUILDING
1976 HONDA CB400F 27 MILES AND BUILDING SOLD

MGNOC # 2723

Offline Antiquar

  • Sunday Rider
  • **
  • *
  • *
  • *
  • Posts: 134
  • 76 850T3, 79 G5, 14 Tiger 800XC
  • Location: Los Angeles
Re: ‘78 Convert weaknesses
« Reply #16 on: January 07, 2020, 07:36:26 PM »
That's a great looking bike TOMB. Bet that fairing/windshield really does the trick.

 

***Wildguzzi Official Logo High Quality 5 Color Window Decals Back In Stock***
Shipping in USA Only. Awesome quality. Back by popular demand. All proceeds go back into the forum.
http://www.wildguzzi.com/Products/products.htm
Advertise Here