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Re: lambretta 290 rotax
Posted: Fri May 18, 2018 9:52 am
by holty
RManson wrote: ↑Fri May 18, 2018 5:58 am
Looking good Holty! What kind of coolant temps are you seeing? Must be maintaining decent temps otherwise that overflow tube would be giving you quite the surprise once it got hot!
I'm running similar initial timing specs, 17 degrees BTDC, total around 24 for now. Will play with it a bit, but it seems happy there. Do you have an EGT gauge fitted? If so, what temps are you seeing? How is the exhaust working out?
hi ryan,
had no overheating at all, we havnt had very warm tempratures though and that might change things, but it stays around 50 degrees c and the very small fan does reduce it slightly when switched on, even sat at traffic lights for long periods it stays cool. ive not fitted an egt gauge yet, i might do in the future, i dont think i really need it as its been set up on the dyno. exhaust works well, ive got the scoot way overgeared its a gt200 gearbox on a 17 46 which gives 3.9 top gear ratio and it will still pull it, it has a slight flat spot just before it comes on the pipe but goes well after that
Re: lambretta 290 rotax
Posted: Sun Jul 08, 2018 10:43 pm
by holty
image by
stephen holt, on Flickr
all ready tp go to cleethorpes
when we got there just had to put the scoot on the dyno just to see what power its kicking out now with some stronger clutch springs fitted, im sure it had some clutch slip when martin set it up, also its got another 300 miles on it now and its loosened up a bit more, hope the video plays ok , it made 35 bhp
happy days
Untitled by
stephen holt, on Flickr
Re: lambretta 290 rotax
Posted: Wed Jul 25, 2018 5:44 pm
by holty
had a little ride out saturday to driffield, then went fo a ride to af rayspeed, scooter ran fine but it starting to get loud, end can needs re-packing
image by
stephen holt, on Flickr
Re: lambretta 290 rotax
Posted: Tue Oct 09, 2018 9:25 pm
by holty
Untitled by
stephen holt, on Flickr
went for a ride to rayspeed today and look who took my scoot for a test ride, non other than mr ray kemp himself, he rode up the road one way, then did a ride past the shop in the other direction while overtaking a car, awsome was the word he used to describe the experience when he got back, when asked how fast he had gone, he said " off the clock about the ton" he also said how nice it rode, very high praise from a scootering legend, wish i had videoed it, great day.
Re: lambretta 290 rotax
Posted: Tue Oct 09, 2018 10:05 pm
by Toddy
What an honour , he’s still got it then
Re: lambretta 290 rotax
Posted: Wed Oct 10, 2018 8:43 am
by holty
Toddy wrote: ↑Tue Oct 09, 2018 10:05 pm
What an honour , he’s still got it then
yes a big honour, i had to go home on it
Re: lambretta 290 rotax
Posted: Wed Oct 17, 2018 5:32 pm
by holty
well ive done a thousand miles now so thought it was time for some maintenance, gearbox oil changed, exhaust was blowing a bit so thought i had best remove it and have a look
Untitled by
stephen holt, on Flickr
turned out the exhaust had a few splits so i welded it up, then welded a patch over it as well just to re-enforce it, one of the brackets was cracked as well so i added another plate and bracket to make it stronger
Untitled by
stephen holt, on Flickr
Untitled by
stephen holt, on Flickr
i have also replaced the rubber mountings with 3 of the same type and added one to the rear can to absorb more vibrations.
i also changed the carb rubber which was fouling on my clutch cable adjuster, screwed the adjuster in and shortened the cable so it doesnt touch now, a change of plug as well, looked quite good for a 1000 miles and never been out of the engine
Untitled by
stephen holt, on Flickr
had some leaking headnuts so added some copper washers, seems to have fixed that problem, got it off my bench today kicked off first time, still very loud but does sound sweeter, test ride tonight
Re: lambretta 290 rotax
Posted: Wed Dec 19, 2018 5:07 pm
by holty
Untitled by
stephen holt, on Flickr
this little baby has arrived from the states
Untitled by
stephen holt, on Flickr
and so the work begins on a little upgrade
Untitled by
stephen holt, on Flickr
same bore size but has a powervalve and a bigger boost port
Untitled by
stephen holt, on Flickr
Re: lambretta 290 rotax
Posted: Wed Dec 19, 2018 8:23 pm
by garry inglis
it will be good to see power difference steve maybe 40bhp
Re: lambretta 290 rotax
Posted: Wed Dec 19, 2018 10:35 pm
by holty
the cylinder is off a skidoo mach 1, they are usually between 95 to 100 bhp as a twin, I have a smaller carb so I would say 40 would be a conservative estimate, the exhaust port is considerably wider than the seadoo barrel which is on now, and the boost port is wider too, ive got a few more jobs to do before I get into it, but will keep updates coming.