Cutting out in 4th gear
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Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Sat Jun 22, 2019 3:55 am quote
Taken out my VBB150 for its first run down after a 3 year restoration (slow I know).

Took it out a few times and seemed ok but today went for a longer drive but only got about 3/4 mile down the road and it cut out in 4th gear! Try to give it more revs but nothing and it just died on me.

Has a Pinasco 177 cylinder head, 20:20 carb and a SIP road 2 Exhaust.

Any ideas? Is it not getting enough fuel or too much when in 4th? I admit I Dnt know the jetting just what came with the carb!
Hooked
59" Allstate
Joined: 03 Aug 2018
Posts: 188
Location: TC Florida
Sat Jun 22, 2019 4:26 am quote
I think you are on the right track. Lack of fuel flow is the first thing id check for.
Did it start back up ? What is the status now after sitting ?
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Sat Jun 22, 2019 4:38 am quote
It starts up again after a minute or two and 2/3 kicks - hit 30mph and then you give it more throttle in 4th and it just hits a dull spot and then the engine dies!

Also has a SIP fast flow fuel tap too
Veni, Vidi, Posti
74 50s x3 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 7186
Location: seattle/athens
Sat Jun 22, 2019 5:12 am quote
Soft seize?

The 177 kit and that pipe DEFINITELY need an upjet from stock or you risk seizing. Time to pull the jets and have a look. Here's a link on how to w/ a chart of what they would be stock. http://modernvespa.com/forum/post2268309#2268309

You could use the stock PX150 w/ 20/20 carb as a reference, you need to be bigger. Jack221 is your expert on how much & the various combinations that work best.

Paging Jack....
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Sat Jun 22, 2019 6:00 am quote
How would I know if it was a soft seize? Any signs?

When it cuts out it will kickstart again a minute later!

This is the first time the engine has properly run since itís rebuild.
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Sun Jun 23, 2019 6:28 am quote
Now it seems to be ok in 4th with plenty of throttle but will stall on idle.

Seems like zero power in the lower revs.

I assume it needs some tuning with the idea and mixture screws!
Feels like its being starved of fuel.

Check the jets and itís running a Dellorto 20:20 carb with a 48:160 and a 112 jet.
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1459
Location: London UK
Sun Jun 23, 2019 6:49 am quote
What your describing makes me think the clutch side oil seal has fell out. Cutting out in 4th is way beyond fine tuning
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Sun Jun 23, 2019 7:03 am quote
What makes you think that Jack? Amateur Mechanic so Iím new to all of this.

Today it seemed on 3/4 to full throttle in 3rd and 4th it felt strong but zero power at low revs to idle.

It felt like fuel starvation as the cure to stop it stalling was more throttle.

Yesterday the opposite which is odd.
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Sun Jun 23, 2019 8:41 am quote
This may be a stupid question but could it be old Fuel with potentially too much oil in the mix that are causing these issues??
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1459
Location: London UK
Sun Jun 23, 2019 9:37 pm quote
Have a look at the gearbox oil level. If the seal is leaking the level goes up or down
Addicted
Old douglas ..smallie with polini 115..super with nasco 177
Joined: 07 Nov 2013
Posts: 560
Location: New Zealand
Mon Jun 24, 2019 6:33 pm quote
Timing
timing. set it to 18 (rotate stator clockwise)
Addicted
Old douglas ..smallie with polini 115..super with nasco 177
Joined: 07 Nov 2013
Posts: 560
Location: New Zealand
Tue Jun 25, 2019 7:19 pm quote
Lecky nish?
Points or "lecky nish"on that VBB 150?...if its got points then reset your gap....better still fit a new set and a new condensor

altering points gap actually alters timing (slightly)

If you are using an electronic ignition then check its set correctly and has not moved or vibrated loose

Should have started with this but after 30 years of working on scoots Im always surprised just how many problems a NEW plug can fix........and also dont under estimate a crap spark plug CAP (no one checks or replaces that bit)

good luck
Veni, Vidi, Posti
74 50s x3 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 7186
Location: seattle/athens
Wed Jun 26, 2019 3:52 am quote
Ant1985 wrote:
How would I know if it was a soft seize? Any signs?

When it cuts out it will kickstart again a minute later!

This is the first time the engine has properly run since itís rebuild.
Ant1985 wrote:
Now it seems to be ok in 4th with plenty of throttle but will stall on idle.

Seems like zero power in the lower revs.

I assume it needs some tuning with the idea and mixture screws!
Feels like its being starved of fuel.

Check the jets and itís running a Dellorto 20:20 carb with a 48:160 and a 112 jet.
A soft seize can happen if you are running too lean. The piston gets too hot in some places, expanding unevenly until the drag on the cylinder wall calls things to a halt. In a soft seize, the piston cools & shrinks, things appear to 'work' OK again but your cylinder & piston are smeared, maybe scored and your rings are probably no longer completely free. Also the chances of it happening again just increased. Maybe even a hard seize w/ piston stuck in the cylinder.

Have you checked the color of your plug or considered a CHT gauge? What is your timing set at?
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Wed Jun 26, 2019 6:41 am quote
V oodoo wrote:
Ant1985 wrote:
How would I know if it was a soft seize? Any signs?

When it cuts out it will kickstart again a minute later!

This is the first time the engine has properly run since itís rebuild.
Ant1985 wrote:
Now it seems to be ok in 4th with plenty of throttle but will stall on idle.

Seems like zero power in the lower revs.

I assume it needs some tuning with the idea and mixture screws!
Feels like its being starved of fuel.

Check the jets and itís running a Dellorto 20:20 carb with a 48:160 and a 112 jet.
A soft seize can happen if you are running too lean. The piston gets too hot in some places, expanding unevenly until the drag on the cylinder wall calls things to a halt. In a soft seize, the piston cools & shrinks, things appear to 'work' OK again but your cylinder & piston are smeared, maybe scored and your rings are probably no longer completely free. Also the chances of it happening again just increased. Maybe even a hard seize w/ piston stuck in the cylinder.

Have you checked the color of your plug or considered a CHT gauge? What is your timing set at?
Will check the plug this evening to see the state - Since noticing this fault I have done at the most 6 miles on the bike so hoping not done not too much if any damage.
I have a feeling it was a mixture of bad fuel and some loose throttle, choke cables from the first few run outs.

Time will tell.
Veni, Vidi, Posti
74 50s x3 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 7186
Location: seattle/athens
Wed Jun 26, 2019 7:01 am quote
The new stalling at idle could be because there's now more friction piston to cylinder. I'd almost have to pull the head off & cylinder up to have a look, but you could drop the muff and get a preview by looking up the exhaust port w/ mirror & penlite or minicam while slowly turning the motor over.
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Wed Jun 26, 2019 2:18 pm quote
Couldnít even get it to kickstart this evening!

Think Iím losing any enthusiasm or confidence I had in this bike! Been a long 3 year restoration with a fading light at the end of the tunnel.
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1459
Location: London UK
Wed Jun 26, 2019 11:24 pm quote
Did you check the gearbox oil. Everything you decsribe says the oil seal has fell out
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Thu Jun 27, 2019 1:49 am quote
Jack221 wrote:
Did you check the gearbox oil. Everything you decsribe says the oil seal has fell out
Still look golden in colour albeit a bit darker - didn't smell bad or of petrol though
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Thu Jun 27, 2019 3:31 am quote
Check the plug and was very oiley.

see photos

65239741_10156598181579075_5263697560454823936_n.jpg

Addicted
Old douglas ..smallie with polini 115..super with nasco 177
Joined: 07 Nov 2013
Posts: 560
Location: New Zealand
Thu Jun 27, 2019 12:57 pm quote
95% of carb problems are electrical
..are you points or electronic ignition?.......smacks of a points gap issue.
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Thu Jun 27, 2019 1:27 pm quote
Bluecati wrote:
..are you points or electronic ignition?.......smacks of a points gap issue.
Points ignition
Hooked
59" Allstate
Joined: 03 Aug 2018
Posts: 188
Location: TC Florida
Thu Jun 27, 2019 2:15 pm quote
Re: 95% of carb problems are electrical
Bluecati wrote:
..are you points or electronic ignition?.......smacks of a points gap issue.
Thats a great thought, What is the point gap ? I looked back in the posts and see you have 18 degrees timing but found no reference of point gap.
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Thu Jun 27, 2019 2:47 pm quote
Think someone above said the move the timing to 18! No idea what it currently is.

Not sure I have the tools to do that myself but will get someone I know to take a look!

It Struggles to even kickstart now though
Addicted
Joined: 26 Jan 2019
Posts: 634
Location: california
Thu Jun 27, 2019 8:31 pm quote
Ant - Your jetting is probably not that far off.
I have a VBB150, stock exhaust and cyl.
It runs a 48/160 primary
100MJ with BE3 and 160AC.
That main stack is mostly compliments of Jack.

Was running very nicely before I took it down for some tuneups.
So that is a reasonable base line.
From there - you would add some additional sizing to the main - at minimum - when you add the pipe and the cylinder.
(It is getting a Pinasco 177 cyl. and a Sip Road II exhaust as yours has).

In this case - it looks like you are 10 sizes over on your main from my base - so ballpark - you are probably not way off (assuming you have the same atomizer and air corrector - perhaps you can check. they make up the top 2/3 of your main jet stack).

Your plug does not look lean...
Assuming you did not have a seal fall out - you most likely have a points and timing issue - not too much to worry about.

Look forward to hearing how it goes once you get your timing/points set sorted.
Then some fine tuning with the jets should deliver some exciting results.

-CM
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Fri Jun 28, 2019 2:58 am quote
Charlieman22 the jets were upped when I had the cylinder kit installed but taking them apart today I can confirm I have the following:

112 MJ with BE3 and 160
Primary is 48/160
Addicted
Joined: 26 Jan 2019
Posts: 634
Location: california
Fri Jun 28, 2019 6:56 am quote
Ok - same as mine - with 12 upsize on main jet.
Not wholly unreasonable.
Those in the know say start rich and work your way down.
Plug looked soaked in your photo.
Wouldn't have thought you would soft seize given looks.
Other's can chime in on that one.
Get those points set and timing sorted - and let's see where you are.
Excited to see you sort through this - will be jetting for very similar set up at end of summer.
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Sat Jun 29, 2019 4:06 am quote
Ok so after all the it just need the fuel hose cutting by a good 10cm and now it works!

I cut it smaller to 24 inches but that didnít seem enough!

Anyway it runs, going to play around with the jets a bit to see if I can get some of the slight hesitation out when applying the throttle.

Glorious day for a ride in england too 30 degrees and sunny!
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
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Location: Millbin, Ostrayleea, mate
Sat Jun 29, 2019 6:16 pm quote
Ant1985 wrote:
How would I know if it was a soft seize? Any signs?

When it cuts out it will kickstart again a minute later!

This is the first time the engine has properly run since itís rebuild.
There's the signs
Addicted
Joined: 26 Jan 2019
Posts: 634
Location: california
Sat Jun 29, 2019 8:06 pm quote
Ant,
Glad it's running well.
As we have matching specs and jetting - and I already threw in my input - just as I threw the pipe on my bike - I thought I would share my first day's tuning experience.
(Electrical gremlins had me "grounded" so hadn't had much chance to test)

Had upjetted 5 points on main.
Left primary alone.

But bike was a bear to start - and I was concerned about soft seiz. Also - it "hunted" and was slow to return to idle. That's classic too lean primary.

i went from 3.3 ratio primary to 3.1. Tried lower but was boggy.
3.1 was majic.

Thought I would share.
FMP says lean primary is cause of seizing - so if ur not certain, might move that richer and move ur way back.

U will hear it gurgling at low throttle driving speeds if u r too rich. Just walk it down until gurgle goes away.

Hope it helps.

-CM
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Sun Jun 30, 2019 2:19 am quote
plan on putting a 55/160 on as well as down jetting to around 105 or a 108 to see if it improves at all
Addicted
Joined: 26 Jan 2019
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Location: california
Sun Jun 30, 2019 7:05 am quote
Since you are still running in your new cyl & rings - might take that walk down on main sizes a bit more slowly.

It's going to make big performance difference as you start to get more optimal on jetting - but you might wanna be a bit conservative as the fuel/oil does the job of cooling.

Do you have a temp gauge/CHT? Knowing temp would be safest means of not getting too lean/ stressing motor.

Keep us posted - sounds alota fun.
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Wed Jul 03, 2019 12:27 pm quote
Thought I had fixed it but after a good 10-15 mile run tonight the bike started to lose power again and cut out in the higher gears.

Seemed to run ok on Saturday but tonight not so much and again struggled to tick over on idle without giving it some throttle.

My 55-160 jet came so Iíll try that to see if it helps otherwise Iím out of ideas.
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'64 Motovespa 150S (177) , '64 V90
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Wed Jul 03, 2019 1:22 pm quote
Ignition.
Addicted
Old douglas ..smallie with polini 115..super with nasco 177
Joined: 07 Nov 2013
Posts: 560
Location: New Zealand
Wed Jul 03, 2019 1:56 pm quote
timing/points
First set your points , as this influences timing......then and only then move on to establishing timing with strobe.As you rotate the stator you alter where the felt part of the points act on the cam lifter...so set the points first.

Sounds like heat is building up after your short run and causing it to cut out..that can be bad timing, high compression(piston gap /bore too tight by 2thou of an inch)

I have also had this (cutting out in 4th) when the new ring gap was too tight..and again heat caused metal to expand

so you mission is to look at

Points gap
timing
ring gap
piston clearance

Id like to check the piston i/bore clearance and ring gap first as if these are incorrect no amount of altering electricals will help
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GL, PK, PE200
Joined: 24 Apr 2012
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Location: Deep in the heart of Texas
Wed Jul 03, 2019 2:20 pm quote
Did you check your tank and fuel tap screen? Maybe trash from the tank is bogging the fuel flow at higher speeds.
Hooked
Joined: 23 Feb 2015
Posts: 128
Location: London
Thu Jul 04, 2019 1:20 am quote
Re: timing/points
Bluecati wrote:
First set your points , as this influences timing......then and only then move on to establishing timing with strobe.As you rotate the stator you alter where the felt part of the points act on the cam lifter...so set the points first.

Sounds like heat is building up after your short run and causing it to cut out..that can be bad timing, high compression(piston gap /bore too tight by 2thou of an inch)

I have also had this (cutting out in 4th) when the new ring gap was too tight..and again heat caused metal to expand

so you mission is to look at

Points gap
timing
ring gap
piston clearance

Id like to check the piston i/bore clearance and ring gap first as if these are incorrect no amount of altering electricals will help
Being very new to the Vespa world and the mechanical side to it - how do I go about checking the bore clearance or is this something I should just give to a professional?
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Old douglas ..smallie with polini 115..super with nasco 177
Joined: 07 Nov 2013
Posts: 560
Location: New Zealand
Thu Jul 04, 2019 1:10 pm quote
vernier calipers
You will need to brush up on how to read a vernier scale..or go to a machine shop .

You need to know the exact measurement of the piston...and another of the bore......there should be a difference of about 4thou of an inch or the metal cannot expand

a machine shop can do this easily...ask them to "Bore it out to 4 thou clear"

My Pinasco 177 out of the box was way too tight at only 2 thou clear

good luck
Ossessionato
1976 Super (x 2), 1974 Primavera (x 2), 2006 Fly 150
Joined: 26 Sep 2013
Posts: 4870
Location: So Cal
Thu Jul 04, 2019 1:32 pm quote
Donít go tearing your engine down. Itís not likely that the piston to bore clearance is causing it to cut out in fourth. Start with the simple stuff.

Iím betting itís an electrical issue. Try replacing the condenser.
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Old douglas ..smallie with polini 115..super with nasco 177
Joined: 07 Nov 2013
Posts: 560
Location: New Zealand
Thu Jul 04, 2019 5:38 pm quote
agree.change that condensor
Yup agree about not opening the engine yet...this is in the "95% of carb problems are electrical" category.

Change the condensor
Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3779
Location: San Diego, CA
Fri Jul 05, 2019 6:53 am quote
if you're changing the condenser might as well put new points in that parts order, because they're the next item to replace in your troubleshooting. after that you'll want a coil.

also see if your flywheel will hold a 17mm wrench with the magnets or not.

based on that plug I'd probably not worry too hard about a seize but later on you can pull the head and check if you're still stumped - it's not that hard.
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