Engine out of frame

[kitchenmatt]

Hi there. 

I am finally about to embark on a restoration of my smallframe. I have attempted it before but other things always got in the way, so its gone so long that pretty much everything needs replacing again. 

One thing I wanted to ask was is it possible to rebuild the engine out of the frame (yes of course it is) but then is it possible to test the engine out of the frame before I put it back in again. Or is this a bit of a pain in the rear end to do so? 

I just find it really annoying, as I am sure we all do, of trying to change the jets and such when its all installed

Thanks for any advice and help

Matt

[boreham]

Hi Matt, there are a lot of frames you can get hold off to build and run the engine out the frame, I got this one from SCK fr about £30 but you can knock one up simply, I’ve even seen them out of wood!

[kitchenmatt]

ah ha fantastic thanks. Nice looking engine, looks slightly more powerful than my trimmed 50cc. It will save me a few grey hairs. I remember last time I tried to tune the engine in the frame and it almost sent me to the looney bin.

Thanks for the help. Ill do I bit of a search.

All the best.

M

[boreham]

Where are you based? Your welcome to borrow this one

[jbcollier]

I vacuum/pressure test my engines before installing them. That is critical. Running the engine? Not so much, and you certainly won't be able to jet it. You need a load to judge the main and transition circuits. Admittedly jetting smallframes is a pain. That's why I routed the carb outside on my last build. It's a real treat to work on the carb now. Rain plugging the air filter is a real problem though.

[kitchenmatt]

boreham, unfortunately based in Stockholm, but thatnks so much for the offer.

jbcollier Cheers for the advice. I didnt consider that you need the load as well, makes total sense. Routing the carb sounds like a good idea, but that might be a little out of my skill level.

I tried to bump up the engine last year and I just ran into loads of problems, so im taking it back to how it would have come out of the factory ( I thill have all the old parts) and get that running, then I can start to replace the other parts one at a time.

Cheers guys,

[kitchenmatt]

boreham Just taking a look at the image you sent or your lovely engine. I can see that the carb and manifold come off the cylinder at an angle, rather than in line with the engine. How does it fit through the actual frame of the scooter?

Cheers
m

[boreham]

Jun 8, 2020 10:13:26 GMT kitchenmatt said:

boreham Just taking a look at the image you sent or your lovely engine. I can see that the carb and manifold come off the cylinder at an angle, rather than in line with the engine. How does it fit through the actual frame of the scooter?

Cheers
m

Hi, the Quattrini does angle at an acute angle, something that could be improved as per the falc etc, I understand it’s for the flow rate, it straight to work better, the downside is you have to open up the hole in the frame to quite a large oval to accommodate, and I mean quite large! Nearly double the original to prevent the reed intake bottoming onto the frame over bumps in the road.

[kitchenmatt]

boreham Yeha I can imagine you have to bore that out quite a lot. I have problems just fitting my standard reed intake in as it is now, doesnt seem to go through the hole enough so it presses against the frame when I get off it. This will be an interesting journey for me.

jbcollier One quick question. I have seen a vid where some bloke is running his engine from the frame, so do you think its a good thing just to try to get the engine starting as it should, then put it in the bike and then do fine adjustments from there?

Cheers guys

[henri]

i run all my engines up in a frame before installing in the scooter ,for many reasons .
1 you can look all around them an check for leaks/problems ,pressure testing is handy but doesnt show leaks that can develope when engine warms up an has full compression .
2 its a lot easier to set mixture an tickover , an get a rough ballpark for pilot jet , no further jetting is possible til engines under load .
3 it saves the grief of getting engine into scooter ,then having to work on it there or remove it ,especially if its a fresh build with new paint to scratch ,this is my main reason .
4 its much easier to strobe an set timing out of the scooter .
5 an i like to see n hear my engines ,its very sastifying .H

[kitchenmatt]

henri Cheers for that, been away for a few weeks so missed the reply. I think ill give it a go. I think the pros weigh out the cons. I only weight 72kilos, so cant imagine the jetting will change too much, but seems like there are a lot of things that you can do out of the frame.

Cheers