Yamaha VETO 40 Help please!

[darren moom]

Hi all.
My yam starts straight away off the key but when the auto choke cuts down, when the throttle is opened it dies straight away. My opinion is when the choke is on, its revving its tits off but when its on non choke tickover, it is about right albiet a little 'lumpy'.
The engine had been stood since july and ive only just bought it. ive changed to brand new petrol and the breather on petrol tank does work (even taken lid off to make sure!)
Any help or advice please?
P.S. its a 1995 motor
Thanks, Daz

[RIB-Teccie]

It's a red herring. The auto choke gives it 30 seconds of additional fuel. The chances are your carbs require to be cleaned out. If you have had the choke off the carbs there are two tiny o rings. If you lose either you will get the same symptoms.

Check spark

Check fuel pump

Clean carbs.

It will be one of the 3. If you have spark it is not CDI.

[darren moom]

Thank you RIB Techie! ive not touched the carbs at all, ive just blown out the fuel filter with airline, and its working a lot better but its not perfect! would a good run down the river help clear it out or isnt that the way?

[darren moom]

bit of an update. Its revving better, but whilst ticking over every 5 seconds or so, seems to miss a beat with quite a squeak of something metallicaly rubbing or catching.?

[RIB-Teccie]

The chances are this is a slow running problem, so there is every chance you wi cut out on the river. I would drain the carbs down and retry. Then I would strip them

[darren moom]

Found the drain screws. blowing them with air line as well. ..

[RIB-Teccie]

The squeak may well be a blown bottom crank seal. Very common. The block will have to come off for that and you must not run it in water as it will track up the crankshaft.

[matt h]

Second everything Rib teccie has said.

[darren moom]

Its now parked up and drained of water. it was only run in a water tub and not continuously at power.. workshop here she comes. Thankyou very much for advice techie,!

[darren moom]

RIB Techie, would you have an idea in how hard a job it would be to replace the crank seals or how much roughly it would cost to do the repair please?

[RIB-Teccie]

If your not confident, buythe parts and bring it to Leeds, I will do it for you. It would be most of the day. If not here goes.

1) you have to be sure that's the problem.
2) How many hours has the engine got on it?
3) Salt or Freshwater use?
4) Remove the plastic cowl and see if the powerhead bolts will crack, but don't undo them.
5) Disconnect everything that attaches the powerhead to the tray.
6) Remove powerhead bolts.
7) Remove powerhead.
8) Remove seal housing (green thing at the bottom of the crank)
9) Don't lose the large washer behind (if there is one)
10) Remove and inspect seals for hardness, marks or tearing. Inspect crank or bottom bearings for corrosion or damage.
11) Clean housing and replace seals the correct way up (springs down to tray) - Grease them in. You can press them in (slip fit) with a socket and vice.
12) Replace 0 ring and grease around face.
13) Put crank sealant on face that mates to block. Surfaces have to be clean. Replace seal housing - grease bolts.
14) Remove gasket from base of block (use a rag to prevent any getting up exhaust) then remove gasket from leg, and ensure both surfaces are clean and dry.
15) Remove float bowls and ensure carbs are clean - you might as well. I would normally do this before anything else.
16) Clean engine tray.
17) Grease drive shaft with waterproof marine grease.
18) Fit gasket to exhaust guide (leg)
19) Replace powerhead and install bolts, greased with marine grease.
20) Replace all connections to tray and, use new plugs and fire up in a large container.
21) Do not touch any other setting like timing and ensure mixture screwed are 1.75 to two turns out from lightly seated position.
22) Cost of parts, probably under £100. I would get from the states.
23) Cost of labour, whatever a dealer charges.
23) I might ask for a good steak dinner!
24) If the powerhead bolts won't shift you could be on a loser. Don't force them. They may still my be with a battery impact wrench, gently at first.
25) If your not a teccie, do not try it at home. Sounds easy but there are pitfalls!

[RIB-Teccie]

I forgot one thing.

The seal carrier is not that easy to remove. Tap gently from side to side with a plastic hammer to remove.

[MrHeadsocket]

Originally Posted by RIB-Teccie

The squeak may well be a blown bottom crank seal. Very common. The block will have to come off for that and you must not run it in water as it will track up the crankshaft.

Not wishing to side track the thread, but my engine (1991 Yam 30HP 3-cyl) has the same problem, it stood for 20 years (answer to why the seals are blown!) And our engineer also picked this up when we had a service, but prior to that we have run our engine at WOT several times and haven't had problems and our engineer said it doesn't matter... however it makes me slightly worried. What chances are there of water tracking up the crankshaft?

[RIB-Teccie]

Every chance. It wi wreck the engine.

[beamishken]

Originally Posted by MrHeadsocket

Not wishing to side track the thread, but my engine (1991 Yam 30HP 3-cyl) has the same problem, it stood for 20 years (answer to why the seals are blown!) And our engineer also picked this up when we had a service, but prior to that we have run our engine at WOT several times and haven't had problems and our engineer said it doesn't matter... however it makes me slightly worried. What chances are there of water tracking up the crankshaft?

I'm surprised that an engineer said it doesn't matter as the lower crank seal is the death knell for many a yam engine
Quite often it's the top bearing that fails as there is a balance pipe from top to bottom
2 stroke cranks don't like water and are easily wrecked if left with the slightest bit of moisture on them
The seal needs doing asap

[A1an]

Just to throw a spanner in the works...

A sneeze/cough/squeak/miss every few second can also point to a lean air/fuel mix....dirty carbs.

[RIB-Teccie]

Which brings us back to the beginning of the thread. Plugs, pump, carbs.

[A1an]

Originally Posted by RIB-Teccie

Which brings us back to the beginning of the thread. Plugs, pump, carbs.

I've found over the years that 90% of outboard running issues are fuel related.

[darren moom]

MASSIVE THANKYOU TO RIB TECHIE!!
It has been a huge learning curve for me today, Techie took the time to strip and clean my carbs, and give motor a good service and clean up. I have learnt a lot today on basic care and maintenance. Looking forward to joining you at Brid in the summer for a good day out.
Again, thankyou very much mate!!

[RIB-Teccie]

Suppose I better give a report.

1) Whoever serviced this engine clearly only knew how to change the plugs! That's about all its ever received.
2) Mixture and Idle screws seized up. (Mixture screws worn)
3) Dirt in bottom carb
4) Top carb butterfly not closing as partially seized.
5) Control cable not set up to return engine to idle.
6) Engine idling at 600 rpm. Raised to 850.
7) Powerhead dirty and neglected, partially cleaned as someone has sprayed that brown sticky crud all over it.
8) Trim reservoir low on oil, topped up.
9) Gear oil emulsified with water. Changed and will require seals.
10) All main gearbox bolts and powerhead connecting bolts removed and greased.
11) Bottom HT lead pared back as it was corroded.
12) Fuel pump checked and gasket to block replaced.
13) Fuel filter cleaned.
14) Prop requires replacing.

This engine had no chance of running properly, simply because it had not been looked after!

Same old same old! RNLI Fodder!