p range main oil seals

[scooter perv]

Having problems lately with these buggers. Have been advised to try viton seals but would like to know what everyone else uses and if its just me being a pillock. 1st engine has gave me loads of grief. p2 rebuilt a few years ago, done about 1000 miles, holds back when revs drops when been thrashing, feels like running out of juice, then goes when open up throttle over half way. Ive rebuilt it, new seals (metal type)change carb, electrics new rings etc etc, problem hasnt gone away. Took clutch out other day and smell of petrol. The plug btw has always been a nice mid chocolate colour and bike has run fine until drop revs on a run. Tickover has been fine and no other obvious signs.

2nd engine. Polini 180 rebuilt for mate, new piston, crank etc. He ran it in and after a few hickups with flywheel, clutch cracking he done the 500 miles. I changed the gearbox oil as he was off to rally this weekend and all was good. Then his clutch went and I bodged a p2 one the night he left so he could use his scoot. Within a bout 50 miles, plumes of smoke, iregular tickover. Drained gearbox oil and it stinks of petrol. Ive used all parts from sip and the seals are the steel Rolf ones. I locktite the seals in and centrepunch a couple of times. Is it me or the seals? What do the builders on here use?

[cezeta]

my ts1 blew a drive seal after 1500 miles. did 14000 miles on the previous seal.

ethonol is said to be the culprit. i filled up in france in a supermarket in june and within 20 miles my new ish inlet rubber had aged 100 years and split

the t5 uses viton brown seals as standard. reed-speed sell the complete set on eBay for the t5 or p range. im wondering now if there is a drive bearing that has a seal in too to give it better longevity

[goldeneye]

i always use the metal backed oil seals, locktited into place. i also use an old , knackered T5 Polini 152cc piston as a seal "knocker", its the ideal size to drift it in. also, when putting the crank in, i grease the inner lip of the seal, and turn the crank a few times as its put in, so the seal doesnt tear. make sure the sealing lip on the crank isnt marked, or nicked. can be frustrating, good luck.

[goldeneye]

my ts1 blew a drive seal after 1500 miles. did 14000 miles on the previous seal.

ethonol is said to be the culprit. i filled up in france in a supermarket in june and within 20 miles my new ish inlet rubber had aged 100 years and split

the t5 uses viton brown seals as standard. reed-speed sell the complete set on eBay for the t5 or p range. im wondering now if there is a drive bearing that has a seal in too to give it better longevity

aye , their is an NU2205 2rs seal , remove one seal, and fit. gives a bit more protection. havnt tried to find one for a P-range.

[cezeta]

yes ive used the double seal drive bearing in lammies but id be keen to see if there is one for a vespa as ive got a t5 motor in bits right now with a fecked crank and nearly a fecked molossi kit as a result of the seal going. (previous owner "rebuilding" the motor but not doing everything...why bother )

[cezeta]

scooter perv, make sure you use a sealant like lock tight on the metal part of the seal to the casing as you leak may be coming from here

[scooter perv]

Ive been using loctite 638 bearing retainer which is good for 0.2 tollerance. So does eveyone use the metal or cheaper rubber backed seals?

[cezeta]

metal for me

[scooter perv]

just tried to find some on simply bearing but the only ones with an inside diameter of 31mm have an outside of 47mm. Looked on ebay at the chap selling viton seals and they is like 30 odd quid. I hope im not gonna regret it but im going back to my cheapo rubber ones..I never had a problem with em years ago, and the engines ive rebuilt lately I thought id do em the right way and it ends in tears, I blame the ethenol

[soullad]

Steve just had 5 or so Vespas in for new drive side seals in the last fortnight. Not good. No obvious similarities, a real mix of metal and all rubber makes.
On the repair stall at the iow had 3 P range flywheel side seals gone, and I mean gone, they were trashed.
Spoke to Chris at CS Engineering today about it and hes convinced its a mix of dodgy fuel (water and ethanol in fuel) and dodgy seal quality. The local garage to him has had a real rise in knackered fuel lines, they just seem to melt away.