T5 motor rebuild
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Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Wed Jun 26, 2019 9:29 am quote
While on an Amerivespa ride the T5 motor began revving at around 8000 rpms. I shut off the key and hit the kill switch but it kept on running. Put it into 4th gear, hit the brake and let out the clutch lever. That did the trick. Iíll see if any damage was done when I open up the cases. Iím thinking I may have damaged the Cush Drive.
Not sure what caused the revving, air leak on the carb box maybe.
I have a bad clutch side seal also, so a rebuild is in order.
Seals, bearings, cruciform, clutch, and Iíll check the top end too.
I rigged up platform to hold the scooter, Iíll see if that makes things easier.
Iím not a good mechanic but I have the time.

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Molto Verboso
Joined: 26 Oct 2015
Posts: 1829

Wed Jun 26, 2019 9:58 am quote
First thing first is to get the engine squeaky clean. A rebuild is much easier when the cases are grease free. I blast the heck out of mine with a pressure washer while the engine is still in the frame. Iíll lay out thick cardboard and or foam mats, lay the scooter over on its side, and clean everything for about 15 minutes.
Molto Verboso
08 GTS 250, 79 P200E, 62 Allstate
Joined: 11 Jan 2006
Posts: 1316
Location: Florence, OR
Wed Jun 26, 2019 7:26 pm quote
Nice temp table for the scooter VP! I'm with WhoDat about getting the engine as clean as possible before opening it up. It sure makes it much easier in the long run. And what always amazes me is I think I've done a good job, then a week later I find a whole are I missed...

Looking forward to this build!
Ossessionato
T5 Pole Position, T for thoroughbred
Joined: 07 Oct 2010
Posts: 4630
Location: Dublin
Thu Jun 27, 2019 3:54 am quote
Are you going to do it motor in situ? handy enough with a t5, you can pop the jug off with it still in frame.
Veni, Vidi, Posti
74 50s x3 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 7347
Location: seattle/athens
Thu Jun 27, 2019 5:13 am quote
Jackson, you old thing! How's your's running? You can easily pop the cylinder on any largeframe using this little trick I learned from Jimmy B years ago.

Reverse the main pivot bolt so the nut is on the flywheel side. Now you can remove the nut, pull the bolt back a couple of inches then tilt the motor a bit so you can pull the cylinder w/ no clearance problems and studs in place.

And yep on trying the rebuild w/ motor in place. I prefer out to clean better & test, but this is doable without a lot of fuss.
Ossessionato
T5 Pole Position, T for thoroughbred
Joined: 07 Oct 2010
Posts: 4630
Location: Dublin
Thu Jun 27, 2019 6:58 am quote
V oodoo wrote:
Jackson, you old thing! How's your's running? You can easily pop the cylinder on any largeframe using this little trick I learned from Jimmy B years ago.

Reverse the main pivot bolt so the nut is on the flywheel side. Now you can remove the nut, pull the bolt back a couple of inches then tilt the motor a bit so you can pull the cylinder w/ no clearance problems and studs in place.

And yep on trying the rebuild w/ motor in place. I prefer out to clean better & test, but this is doable without a lot of fuss.
Im not bad buddy. Mine isnt bad, trying to work out an issue but its ride-able. Trying to get back on in here a bit. Used to love it. Just find it a bit weird without Chris and Jim. Still really shocked

Sorry to hijack Vp.
Veni, Vidi, Posti
74 50s x3 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 7347
Location: seattle/athens
Thu Jun 27, 2019 11:55 am quote
Good to hear from you and also still broke up for them. They added so much that was unique. And we soldier on, so don't be a stranger!

What 'issue', we got a all the help you need, just no HELP ME button Back to Vp with more possible assistance, another tip:

If you do it in the frame and you don't need to pull the crank, you can even split the case without pulling the cylinder by removing the outer two cylinder studs first. Nothing but case bolts(some under the stator) and friction holding it together now. Of course you need a good base gasket that stays with the cylinder for this to work, so best as a get-out-of-a-bind fix, it's not the Piaggio way. Also, loosen the other two cylinder studs a bunch & lift the cylinder a bit when you reassemble.
Ossessionato
T5 Pole Position, T for thoroughbred
Joined: 07 Oct 2010
Posts: 4630
Location: Dublin
Thu Jun 27, 2019 1:46 pm quote
I done full strip and rebuild on my t5 a few weeks ago. So any questions throw them up and Iíll try answer
Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Thu Jun 27, 2019 3:57 pm quote
Iím going to pull out the motor. I plan to replace the clutch side seal. Probably easier with motor out.
Heat the cases, freeze the seals and bearings.
Things look okay so far, the cylinder looks good, piston too, no scoring on either one.
Iíll try to get the motor out tomorrow.

FCB3BC6F-620F-421F-85FB-AA6DC38364B3.jpeg

Ossessionato
05 Stella, '62 VBB, 76 Sprint V, 63 GL
Joined: 16 Jun 2011
Posts: 2256
Location: Chicago. Well, Evanston, but that's almost Chicago
Thu Jun 27, 2019 4:18 pm quote
My biggest issue with rebuilding in the frame is dealing with the clutch nut and the crank removal & installation tools.

For doing a top end swap, that's not a big deal, but given that the need for the rebuild seems to be the clutch side seal, I'd say pull it out. Looks like you already have the tricky bits of the disassembly done, though.

Are you doing bearings, too, or just seals, buffers, kick start gear, etc?

Mostly, rebuilds are about taking your time to do things correctly and not trying to force anything.

And leak testing. That's the ultimate determinant of success. Does it hold air once it's all buttoned back up?

You got this!
Ossessionato
T5 Pole Position, T for thoroughbred
Joined: 07 Oct 2010
Posts: 4630
Location: Dublin
Fri Jun 28, 2019 12:50 am quote
I wonder was the revving a leak issue, or simthing silly like the outer popping out of where it goes into the carb box adjuster...
Ossessionato
T5 Pole Position, T for thoroughbred
Joined: 07 Oct 2010
Posts: 4630
Location: Dublin
Fri Jun 28, 2019 12:52 am quote
Love your scoot by the way,

White T5s are great looking with all that black trim
Ossessionato
T5 Pole Position, T for thoroughbred
Joined: 07 Oct 2010
Posts: 4630
Location: Dublin
Fri Jun 28, 2019 3:27 am quote
If you are ordering parts, you might as well get new piston rings. They wear pretty quickly on them due to the revvy motor.
Ossessionato
05 Stella, '62 VBB, 76 Sprint V, 63 GL
Joined: 16 Jun 2011
Posts: 2256
Location: Chicago. Well, Evanston, but that's almost Chicago
Fri Jun 28, 2019 4:57 am quote
jackson85 wrote:
I wonder was the revving a leak issue, or simthing silly like the outer popping out of where it goes into the carb box adjuster...
Sadly, no, he was leaking massive amounts of gasoline into the gearbox.
Ossessionato
T5 Pole Position, T for thoroughbred
Joined: 07 Oct 2010
Posts: 4630
Location: Dublin
Fri Jun 28, 2019 5:17 am quote
chandlerman wrote:
Sadly, no, he was leaking massive amounts of gasoline into the gearbox.
I had to rebuild mine for the same reason. i was hoping it was the flywheel side since the revs dropped with i gave that area a blast of carb cleaner. but then the gear box oil told a different story. So that was that. time to crack it open. Its nice to have it done and you dont have to worry about things for a while. Just refresh everything while its apart
Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Fri Jun 28, 2019 11:30 am quote
I donít know what caused the scooter to rev like it did. Itís possible the throttle cable outer got hung up, but it wouldnít shut off when I used kill switch and turned off the key, so I think maybe it was an air leak at the carburetor that didnít show up until the motor got hot. Probably had nothing to do with the clutch side seal.
I may use a thicker gasket under the carb box this time.
Motor is out, Iíll give a good cleaning this weekend.

image.jpg

Ossessionato
T5 Pole Position, T for thoroughbred
Joined: 07 Oct 2010
Posts: 4630
Location: Dublin
Fri Jun 28, 2019 1:26 pm quote
I used kerosene to clean mine. Clean as a whistle
Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Fri Jul 05, 2019 6:26 pm quote
Looks like the crank on the T5 is bad, there is some play in the connection to the conrod. Iím not going to try to rebuild it. SIP has one for the T5 for $159, Pinasco has one for $212. Any opinions on which to choose?
Also the air intake on this scoot looks like itís been modified.

D20DBF1E-1729-426E-9554-C0F8FF5CA760.jpeg

Molto Verboso
1979 P150X, 1983 P200E, 1987 T5, 1996 PX200E, 2011 Yamaha Fazer 600 S2
Joined: 02 Aug 2015
Posts: 1619
Location: Veria, Greece
Fri Jul 05, 2019 11:51 pm quote
Personally, I found a NOS original conrod and rebuilt my crank. Both cranks look good, Pinascoís maybe a bit better...

Inlet is fine. Thatís how T5s are...
Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Wed Aug 07, 2019 11:12 am quote
Rebuilt the Cush Drive, installed a new crank. I should be able to put the cases back together tomorrow.

73A66F49-F6AC-407A-AF9E-75BC964B54D5.jpeg

Enthusiast
GS150, LI200, TX200, PX125, T5200, SX200, PX125 CUTDOWN
Joined: 31 Jul 2019
Posts: 72
Location: South West England
Thu Aug 08, 2019 3:26 am quote
I gotta do an engine teardown to my T5 in the next few weeks too. Clutch side seal looks like its gone. Gear oil sprayin' out onto rear inside tyre. Lots of good tips on this thread. Thanks all!

Your T5 looks ace btw.....
Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Fri Aug 09, 2019 6:43 pm quote
Got the cases back together and things are looking good. Had a bit of trouble installing the clutch, I had to tilt the woodruff key in to get the clutch on.
Also a bit of trouble installing the cylinder. I put the bolts on and tightened them, then put the piston in, but when I tried to put on the head there wasnít enough bolt left. Had to remove the bolts one at a time and back them out a bit (I used blue Loctite) in order to get the head installed.
Will try to put the motor in Monday!
Enthusiast
P Series / Li / LML / Motobi
Joined: 24 Jun 2019
Posts: 96
Location: 3rd Rock From the Sun
Sat Aug 10, 2019 3:46 pm quote
Vpfalcon wrote:
Got the cases back together and things are looking good. Had a bit of trouble installing the clutch, I had to tilt the woodruff key in to get the clutch on.
Also a bit of trouble installing the cylinder. I put the bolts on and tightened them, then put the piston in, but when I tried to put on the head there wasnít enough bolt left. Had to remove the bolts one at a time and back them out a bit (I used blue Loctite) in order to get the head installed.
Will try to put the motor in Monday!
Studs in wrong way round
Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Sat Aug 10, 2019 4:55 pm quote
The studs had the same number of threads on both ends. I added a bit blue Loctite and reinstalled them.
Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Sun Aug 11, 2019 7:02 am quote
I did some checking this morning on the T5 cylinder studs. They are m8 x 125mm. On most Ps they are 150-160mm.
The cylinder, piston, and head had been replaced on my scooter before I got it, and I think the new parts are a little taller than the originals. Thatís why I had to back out the studs a few turns. But since I was able to torque everything down to specs it should be fine.
The m8 x 150 cylinder studs may be too long anyway.

A40AA77A-2660-4483-B1BE-A8B606042DB7.png

Hooked
1986 T5,
Joined: 30 Oct 2014
Posts: 450
Location: Oak Brook, Illinois
Fri Aug 16, 2019 7:09 am quote
Scooter is back together and running well. New seals, bearings, crank, rebuilt primary drive, rebuilt clutch.

0996CCD6-4210-4A4A-A759-24AEB4DF3672.jpeg

Molto Verboso
08 GTS 250, 79 P200E, 62 Allstate
Joined: 11 Jan 2006
Posts: 1316
Location: Florence, OR
Fri Aug 16, 2019 9:13 am quote
Right on Falcon! It's been fun watching what you ran into along the way, and how you got around it.

I'm glad to see your scooter is on the road again!
Molto Verboso
Joined: 26 Oct 2015
Posts: 1829

Fri Aug 16, 2019 6:11 pm quote
So is the throttle slide closing all the way? If not, the carb could be warped.
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