Search found 211 matches

by RManson
Fri Dec 15, 2017 5:51 am
Forum: Liquid Cooled, Motorcycle Engine & Automatics Section
Topic: Rotax 300 builld
Replies: 242
Views: 120464

Re: Rotax 300 builld

good man, and thats a very good price, we get crippled with stuff from the states, over here, import tax, im sure you will get it sorted, ive checked my stinger and its 26mm id, i might have to do an upgrade. holty I would definitely have a look at the stinger size, especially if you have a silence...
by RManson
Thu Dec 14, 2017 10:09 pm
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11767

Re: Detonation, lean seizure, or....?

Thanks Holty! As you said, it's to be expected and if I'm honest, I actually expected much worse when the time came for things to go South. Good news is top end replacement is already on the way for under $100. Will inspect the parts once they arrive but the bore looks good and the piston is new, so...
by RManson
Thu Dec 14, 2017 10:06 pm
Forum: Liquid Cooled, Motorcycle Engine & Automatics Section
Topic: Rotax 300 builld
Replies: 242
Views: 120464

Re: Rotax 300 builld

Thanks Holty, Already have a new barrel, piston and head on the way. All for under $100, bearing testament for why I went with this setup to begin with. I overlooked the importance of the stinger size and I think that was the problem. With an EGT gauge, we should have seen that. Suffice to say, I'm ...
by RManson
Thu Dec 14, 2017 8:52 pm
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11767

Re: Detonation, lean seizure, or....?

Something for holty to keep an eye on as he built his too suit you are both clever builders and it's been very informative to follow these builds and overall for what you have done engineering wise it's a small setback Agreed. This plus holty's info would make a great basis for a scootering article...
by RManson
Thu Dec 14, 2017 7:26 am
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11767

Re: Detonation, lean seizure, or....?

Darrell, I think I agree with you. At the moment, that definitely makes the most sense. The whole exhaust has been modified to suit the build and start life as a YZ 250 unit. I tried to keep the dimensions as close to stock as possible but didn’t think about the stinger diameter. I did run the numbe...
by RManson
Wed Dec 13, 2017 11:08 pm
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11767

Re: Detonation, lean seizure, or....?

As you've mentioned, it doesn't appear to have been running lean and timing doesn't seem to be off, at least at that moment. I can attest to the AFR being in the 12:1 range almost across the board (apart from closed throttle/coasting) as I tested it with an AF Meter. Timing was 24 degrees at 4,500, ...
by RManson
Wed Dec 13, 2017 10:42 pm
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11767

Re: Detonation, lean seizure, or....?

When you originaly set the piston within the barrel at bdc was the top off piston level with the transfer ports and usually 1/2mm over the exhaust port if below you would open up the exhaust port but if it was 4/5 mm over the exhaust port at bdc it get to hot on the edge that's showing in the photo...
by RManson
Wed Dec 13, 2017 7:46 pm
Forum: Liquid Cooled, Motorcycle Engine & Automatics Section
Topic: Rotax 300 builld
Replies: 242
Views: 120464

Re: Rotax 300 builld

I don't see a probe anywhere near the exhaust. Air/fuel mixture perhaps? Not ruling anything out but things looked good on the air/fuel meter before running the bike on the dyno. We were only planning on making a few pulls to get a power number, not to test and tune as they're not really set up for...
by RManson
Wed Dec 13, 2017 7:44 pm
Forum: Liquid Cooled, Motorcycle Engine & Automatics Section
Topic: Rotax 300 builld
Replies: 242
Views: 120464

Re: Rotax 300 builld

Well, things started off promising. https://farm5.staticflickr.com/4517/38304371774_3df5ec7b64_h.jpg IMG_6131 by PotvinV8 , on Flickr That looks like a decent dyno setup, who/where is it? It's the test dyno at Hot Bike Magazine here in Southern California. They use it for product testing, etc. and ...
by RManson
Wed Dec 13, 2017 7:42 pm
Forum: Liquid Cooled, Motorcycle Engine & Automatics Section
Topic: Rotax 300 builld
Replies: 242
Views: 120464

Re: Rotax 300 builld

Stampede wrote: Wed Dec 13, 2017 7:47 am Do you know the reason for the breakdown?
The verdict is still out on the cause, but I have a few suspicions and am looking into everything. Will post what I find for sure.