Diary of a GP200 Engine Build

I've never built an engine before and I've no idea how successful this will be. Armed with the best advice from the Lambretta Club of Great Britain website and their Forums. The new Complete Spanners Workshop Manual for Lambretta Slimstyle Scooters by Sticky, the Home Workshop Manual & The Unofficial Lambretta Manual Update I shall do my best to build a GP200 engine.

Here's the casing.
Don't be fooled by the Innocenti markings inside and outside the casing, it's Indian made.

 

Monday 28th February Took delivery of the top end today. Stage 5 tuned Mugello 225. The crankcase transfer ports have been matched to the cylinder (including mag flange). Also included a 30mm Dellorto. (GP Race crank to follow).

 

Tuesday 1st March Tapped out all the M6 & M8 threads.

 

Tuesday 1st March chaincase studs all in place.

 

Monday 22nd March Heated up the mount flanges to insert the mounts. Even with the correct tool, the mount flanges still needed heat to make fitting easier.	Monday 22nd March Mounts fitted

Monday 14th March
Posted the exhaust off to Jahspeed to get a slip joint made.

Monday 22nd March Now showing the crank fitted, but I had hassle getting there. I had a problem fitting the main bearings and I wasn't convinced they were in right. I removed them and put a new set in. Heating the casing and freezing the bearings for a few hours and using a main bearing fitting tool made all the difference. The halite washer and oilseal plate with the oilseal went in next. I had to trim the halite washer to get it to fit right. Then the crank went in.

Monday 22nd March Front sprocket assembly is now in place. 18 tooth front sprocket

Sunday 9th April
The past weeks updates...

Fitted the nice new layshaft.

Rear brake assembly went on.

In went the gearbox (Italian LI150)	On went the endplate

 

On popped the top end	In slipped the clutch

Actually, things didn't quite "pop" or "slip into place". There's a few things that had me tearing my hair out this week. Fitting the gearbox was one. It wouldn't shim up prperly and after a whole day of farting about it transpired that part of the o-ring from the layshaft had come away and had stopped the layshaft from sitting properly. Once that was sorted the endplate went on without a hitch and shimmed up correctly.

The top end went on swimmingly well (for a fud like me anyway). I even managed to get a good measurement of squish, after using the smallest of three headgaskets supplied with the kit.

Tuesday 19th April 2005

The engine build is complete. I'm not sure it'll run, but the engine build is complete!

I've yet to wire up the stator plate wires & I'm also still waiting for the exhaust, but other than that as far as I can make out I've done everything to the best of my ability. I just hope it runs ok. I'm not sure when I'll be able to get it running.

 

Monday 15th August

Update on the engine.

I got the engine running and after an a problem with a worn kickstart reference pin that caused the piston to engage first gear, the engine is running. The jetting just needs fine tuning. currently 600 miles on the clock.