Malaguti F10 Low compression

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malteser
Posts: 5
Joined: Mon Nov 13, 2017 7:03 am

Malaguti F10 Low compression

Postby malteser » Mon Nov 13, 2017 7:13 am

Hi everyone,

This might be a long post but I really could do with some help on this. I recently purchased a non running F10 1996 model. I have done the following list of things and I just can't get it to fire up at all. When I turn it over it turns over pretty well and I can hear a hissing sound from the compression but it won't fire up. I also can't see any fuel going to the cards from the fuel cock however it is my understanding that fuel will only travel when it is started due to the vacuum.

I have done the following:

completely stripped the engine
Installed new shaft seals
Complete new engine gaskets
New piston and rings. I paid attention to the bevelled side up on the rings and to have the slits set apart due to compression.
New Fuel Cock
New air filter
New clutch flywheel

I am trying to run a compression test but it's only going up to 25psi. I had tried putting some fuel in the cylinder to see if fuel is an issue but it won't fire up anyway. I tried a spark test and it seemed ok but I will buy a new plug just in case. The only thing I can think of is that when I closed the lower part of the engine case that it didn't seal perfectly at some point. I thought that the compression only came from within the cylinder part.

Any ideas as to why this won't fire up. I have run out of ideas. The only thing I want to double check is to make sure that I have installed the arrow towards the exhaust on the piston.

Many thanks in advance.

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50kFacePlant
Posts: 46
Joined: Mon Sep 23, 2013 9:36 pm

Re: Malaguti F10 Low compression

Postby 50kFacePlant » Sat Nov 25, 2017 7:39 am

check ur piston rings, may have broken one installing the piston

malteser
Posts: 5
Joined: Mon Nov 13, 2017 7:03 am

Re: Malaguti F10 Low compression

Postby malteser » Sat Nov 25, 2017 11:29 am

I just bought a new cylinder and piston. rings and pin. I will be installing them tomorrow morning all going well. I'm thinking that the cylinder might have been worn as the rings were ok, or they looked ok.

Thanks.

malteser
Posts: 5
Joined: Mon Nov 13, 2017 7:03 am

Re: Malaguti F10 Low compression

Postby malteser » Sun Nov 26, 2017 10:20 am

Ok. So I installed the new cylinder and piston and rings and the scooter fired up after a few squirts of starter fluid. I then had to suck on the vacuum line for the fuel to get fuel in and it starter everytime.

I took in round the block a few times and it felt underpowered and it was smoking a fair bit but that tended to reduce once I turned the fuel/air screw on the car. I came home and after a few hours I tried starting it again and it wouldn't fire up. Most likely it's not getting any fuel.

Do you think I can try to set the carb or find the idle, air/fuel mixture settings online?

I will get it to fire up tomorrow I'm sure but I would like it to set it up correctly.

Thanks again.

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50kFacePlant
Posts: 46
Joined: Mon Sep 23, 2013 9:36 pm

Re: Malaguti F10 Low compression

Postby 50kFacePlant » Mon Nov 27, 2017 3:14 pm

use atleast 95octane fuel.

malteser
Posts: 5
Joined: Mon Nov 13, 2017 7:03 am

Re: Malaguti F10 Low compression

Postby malteser » Mon Nov 27, 2017 4:10 pm

Hmmm. I don't have an option with the fuel. I am in Malta and I believe that there is only one type of petrol dispensed at the gas station. I didn't think about that.

I had it running again today but only when I took off the airfilter and used the starter fluid. So it starts with the fluid and then if I partially block the carb air intake it stays running sometimes.

I tried pulling off the fuel line from the carb and turning it over to see if fuel was pumping and nothing happened.

I checked the seals from the carb boot and the reed valve and they appear to be tight. I wonder if there is a vacuum leak somewhere?

I had also bought a new carb boot though recently. So there must be something wrong with the carb itself possibly.

dan v
Posts: 355
Joined: Thu Nov 05, 2009 5:45 am
Location: Grand Rapids, Michigan USA

Re: Malaguti F10 Low compression

Postby dan v » Thu Nov 30, 2017 7:41 pm

As I read this over, I see you have had it running around for a bit, but when shut down for a while it is hard starting.
Of course you checked your kill switch and made sure it is in the run position?

The hard starting sounds like a fuel issue, as it starts and runs when you cover (choke) the intake with your hand, right?

Check your fuel tap (petcock) by removing the fuel and vacuum lines from the carb. Attach an appropriate sized tube to the vacuum connection and lightly suck on it. You should have a good flow of fuel. If not, then tap is bad.

If you have good fuel flow, then clean the carb well if that has not been done.

F/A screws on the carb is usually about 1-1/2 turns out. Idle is set when the engine is warmed up.

OK then, if you can get it to start and idle (sometimes you have to crack the throttle to start, and kicking may bring it to life better than the electric start) then you can check for vacuum leaks. Using carb cleaner with a straw in the nozzle, spray the running engine in several places. Carb/intake connection, manifold/case connection. Cylinder base. Case seams. If engine speeds up you know you have a vacuum leak. Make sure your exhaust is tightened correctly to the cylinder, too.

I'm going to assume that putting a new kit on it has taken care of any compression issue. When the engine was rebuilt, it could have benefited from a leak-down test. There are threads in here as to how to build a tester and use it.

You know that you have to have air/fuel/spark for any engine to run. If you have good fuel flow from the tap and it still doesn't want to run well then further testing is needed. I can tell you that the F10 in the stock form is pretty weak, so don't expect a strong runner, but it should get you around. Hopefully this back to basics will help you get it sorted.
How many scoots is too many?

malteser
Posts: 5
Joined: Mon Nov 13, 2017 7:03 am

Re: Malaguti F10 Low compression

Postby malteser » Fri Dec 01, 2017 5:27 am

Hi Dan,

Super thanks for the reply.

Ironically I just fixed it before your message came in. I researched the carb settings as you said and that was the issue. Basically what I did was to close the fuel/air screw and the idle screw and open them both by two turns exactly. I also took out the spark plug and turned over the engine to pump out extra oil and fuel as I looked at the plug and it was soaking wet.

Turned it over and boom. It fired up. I took it for a spin and noticed it was bogging and smoking alot so I left it running and played with the air/fuel setting and reduced the idle a little and it is working perfectly. I then took it for a good 30 minute ride and it worked really well. Have to agree on the low power though. I bought this as a project bike for fun more than anything and was super happy to see this running as it has had been neglected for a few years prior to me buying it.

As you mentioned though, the screws settings was the issue.

Once again many thanks.


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