1200 Engine rebuild and other stuff

[VesaII]

Hi All

Next problem is no idle. It just disappeared after ecu got a proper ground and everything was back to more normal.

TPS is adjusted, but air screws are closed as many of us have when throttles are balanced with this rod and now i think they should be opened but how much? As i recall one throttle body should have fixed value for this valve, and only other valve should be adjusted when balancing the vacuum.

[VesaII]

Solved the idle problem initially by adjusting throttles to 6 degrees and then resetting TPS and opened the air valves half of turn both. Now i have quite good idle.

[VesaII]

Looks like changing mapping when engine is cold or hot does affect results. Similarly hot engine has different TPS values than cold. Crap...

[Falkone]

how much is the difference?

i had never notice that at my normal corsaro.
Cold or hot engine ist every time 2,7-2,8° when the engine is stop.
With running engine is that Morini ground problem (from 1.2 - 2.8°)

But fix it like it was described in these topic... I had to try it the next week and see the result...

[morluk]

Hi Vesa
We already talked about your TPS problem. The sensor you have already changed.
The tps sensor is connected to the plug on the left side of the Airbox. From there the wiring is going directly to the ecu. Have you already tried a direct cable from the sensor to the ecu. Maybe your ecu has a problem. Have you already tried another ecu?
I have a maximum deviation of 0.1-0.2 when the engine is stopped and when it’s running.

Heinz

[VesaII]

Hello guys

Today i had time to measure this for real. Now i am convinced my TPS problem is cause of worn out throttle body.

This is checked by shaking rear throttle axle and simultaneously see TPS values with PC. Play is not more than 0.1-0.2mm, but shaking of axle makes TPS values to fluctuate between 4-2. When i am moving throttle by wire, then it is quite nicely 2.7. Hot or cold.

One more weird thing is that value drops when engine is started and cold, but goes toward 2,7 when temperature rises.
So i think there can be problem with ecu too, but sure with throttle axles. Front cylinder body is even more loose (0.5-0.7mm) It makes flapping sound when engine is running as axle and butterfly valve moves up and down.

When engine is running then TPS values walk around as flaps position constantly changes. This might be the root cause for jerkiness and idle and stalling issues for many of us and not the mapping, partly at least.

Even i am quite sure what i need to fix next i any. way changed a new TPS sensor as i had one original Magneti Marelli over. Changed it mainly cause of better build quality than my first replacement (Esen SKV)

Anyone who have fixed issue by rebuild and is it axle or body which get worn out?

[VesaII]

Hello

Got tired to bad idle, jerking, stalling and playing with TPS reset, mappings etc. when root problem is on mechanical side. This is play on shafts as it affects directly to TPS which begins to fluctuate and slightly on the amount of air on small throttle openings.
Usually there is nothing wrong with your TPS sensor. Wonder how many of us have replaced sensor unnecessary...

Luckily shafts are not worn out but bushings which need to be replaced, which is not easy task, but i found a mechanic who can fix this kind of delicate things. Lookin for <0.05 play on shafts.

And i need one new butterfly valve (blue arrow) If you have one over from worn out throttle body, please let me know.

All ideas are very welcome though...

[VesaII]

Bushings (SKF) replaced and extra tightened.
Now TPS holds 2,7 quite steadily when engine running. No road test done yet, but how much cleaner it run now on idle and responsive and constant when turning throttle and this with old map from previous dyno run, which is quit much off cause of earth problem i had then.

Removed also minor play on front throttle with Araldite (red arrow) as screw adjustment here is useless.
And drilled two small holes for oil to squirt in by a syringe (two red arrows) This side is prone to wear more, especially rear one thus TPS issue.
Thanks for Heinz for TPS adjustment advice. Air screws are now fully closed and flaps extra opened for proper idle instead.

Parts cost was under 50e and axles are now more tight than new throttle body (price 1ke)

Then i have dyno run left and dual lambda modification. Goal is to make motor run more smoothly and with enhanced fuel economy.

Now one thing is confirmed at least. If you have low TPS issue (< 2,4 = outside of map thus uncontrollable) when idling, then your bushings need to be replaced, obviously.

Ps. still looking for a butterfly valve to buy

[VesaII]

Hello all

Story continues... Visited the only licensed MotoMorini mechanic in Finland and asked his opinion about high oil consumption and contamination issue on front cylinder intake valves and engine breathing and how it affects oil consumption. His suggestion is new valve guides of bronze and with tight tolerances. Same time he like to replace valve seats to something copper based as this might help in many ways.

Wonder if someone have done this and do remember the size of seats that fit on heads? Tried also find some Germany company manufacturing valve guides and restoring heads. Anyone have this information?

[morluk]

Hi Vesa.

I brought once a welded Honda RFVC Cylinder Head to Häring Motorinstandsetzung in Regensburg. The Aluminium Head had Cracks between the sparkplug hole and the outlet valves and has been welded before. They restored the spark plug hole and the valve seats as well.
They did a good job in a short time . It’s still a small craft workshop an I didn’t find any homepage. For contact you have to call them. +49 94184265
If you describe exactly what you need from them I can call them for you.

Heinz

[VesaII]

Hello Heinz

Thanks for help but luckily my heads have no cracks and we have many machine shops able to do valve jobs. Reason why i asked company is valve guides they are using if not same Freccia G11308 11.07mm x40.5mm (Renault 1.5dci) already used on Morinis

Only thing needed is new seats and valve guides. Actually i yesterday visited one machine shop. They charge 500e for the job with basic materials, which is steel seats and bronze guides. Guys also gave me two european companies who are selling more advanced stuff. https://www.metelligroup.it/en/Products/Engine_parts and http://www.moldstar.com/
These are most interesting so far as i am looking for better heat transfer than Morin originals, cause of intake valve contamination caused of burnt oil: Metelli S07= cobalt-molybdenum steel alloy with copper infiltration. viewtopic.php?p=54716#p54716

But before opening the engine i will test crankcase pressure hypothesis with reed valve assembled instead of aluminium plug inside the blow by valve. Normal breathing tube will be clogged so negative pressure will be created inside the engine and oil, for sure, is not forced thru valve guide sealings any more. I hope this way whole operation becomes unnecessary and this even solves or minimizes front cylinder intake valve contamination problem at least in some degree and engine should be more oil tight generally too.

Mine is maybe a slight overkill and something like this with only one valve might be enough. But you still need proper extension to emulate blow by valve aluminium plug.
http://www.mapcycle.com/uncategorized/m ... -nice.html
http://www.mapcycle.com/uncategorized/m ... steel.html

[VesaII]

A few things under construction but lets take one minor first.

As we know injector body axles are not fitted perfectly even when new and any play there makes TPS fluctuate. Cause of this i decided to rebuild body once more and minimize play or rather remove it completely.
Off with old bushning with 5/16 UNF thread tap and replace them with new (steel SKF 8x8x10 PTFE coating) ones, but you need to do some tricks to achieve the goal.
Bushings are not tight enough as they come from factory, so they need some sanding to open them with a few tenths to allow more tight fitting. Even axles have some unevenness and must be removed to get axles in place. Photos show how to proceed.
-> My axle play is practically zero now and TPS should be mechanically as stable as it can get. Drilled also two extra oil holes for axle lubrication.

Today i might choose Nomo. https://nomo.com/en
They have at least two interesting versions applicable NB2Y and NB2S

[VesaII]

Many of us have had problem with worn out valve guides. My hypothesis is valves with damaged hard chrome plating is the cause. You can harm chrome plating by sanding and have worn out guides after a few thousand km:s . No matter if guides are iron or bronze or sintered. You are better off if you change valve every time guides get worn out or any time you do any valve job. This i true especially on intake side. Exhaust shafts are of better material, maybe. Any way i only have had problems on intake side.

My heads are now at new machine shop and they have material issue with valve seat, one at least. New top quality guides and valve seats will be installed and pefect condition valves to ensure longevity, finally.

[VesaII]

We are proceeding

Old seats are like this:
41.65 x 35 x 8mm
35,65 x 29 x 8mm

Idea is to use overkill material on new seats and one alternative is sintered iron with copper
Metelli 46 x 30 / 06-S010
Metelli 36 x 21 / 06-S015

Or Dura-Bond KillerBee
https://www.dura-bondbearing.com/parts-search/

Other alternative is to make own. Material for this i found
Moldstar90
http://www.moldstar.com/newproducts.html
JM7
https://sacometal.fi/en/services/bronze ... -bearings/
Ampco 45
https://www.ampcometal.com/products/amp ... /ampco-45/

On picture you see how seats was removed with smaller valves welded fast on seats and then heated and popped out.

[VesaII]

https://specialmotorsengineering.fi/en/ hand made one beautiful set of 'hole in one' 42,5 x 34 x 9mm and 36,5 x 28 x 9mm seats of Ampco45.
This all in one week and at very affordable price. You may order valve guides of same material.

One extra goal with better valve cooling is to play with different ignition timings more safely

Some background:
https://www.prnewswire.com/news-release ... 02690.html
https://www.mobilityengineeringtech.com ... orts/43252
https://www.tomorrowstechnician.com/eng ... ts-guides/