KB2T,A Warning!

[Nik da Greek]

Hahaha Castrol R FTW! Dunno what they use in modern GP strokers, but they still smell just as good now! I\'m getting all nostalgic for the days of my old LC reading this thread lol

[dubber91]

On a different note, I have run very cheap scooter two stroke oil in my 12a with absolutely no problems for in excess of 10k. I have stripped an engine that has done only idle time which had heavy carbon build ups because the map was too rich. I honestly dont beleive the oil is at fault.

[Jono FD3]

Castrol R, don\'t care what it ever did to the engine because once smelt that gorgeous smell lives with you for ever :Thumbs-up:Thumbs-up:Thumbs-up

They were still using this in the F1 Circuit powerboats untill a few years ago!! & must agree...... Oh what a smell!! shure it wasn\'t very good for the health though :Giggle but MMMMMMmmmmmmmmmm :mmmm

Jono

[Bob Monkhouse]

F1 powerboats are stripped after every race, carbon build up is not an issue. I have raced two strokes and tuned them for many years and was at one time considered quite an expert on them( I had a severe head injury a number of years ago which curtailed just about everything). When Iused to use \'R\' the engines were stripped after every race and had a film of oil on everything. This was running at 25-30:1.The only experience of castor based oil in rotarys was last year as I have said. As Carl mapped the car and I regularly check it on our Sun gas analyser(a proper one,not one of these crappy gunson things) both myself and Carl are satisfied that the excessive carbon build up was due to the KB2T.Running something at 125:1 horrifies me, but thats the norm for a rotary, after all, there are no needle rollers for the oil to \'flash off\' and cause a seize. I\'m not saying don\'t use it but be aware that it does lead to carbon build up which is in excess of the recommended oil for a Mazda rotary engine. With my two stroke experience, engine oil would be the last thing I would normally put in a pre mix but then again, Mazda know a lot more about this than I do. The second to last thing I would put in a two stroke would be cheap two stroke oil. Do that in a high revving two stroke and the engine ain\'t gonna last two minutes. One last thing, the F1 power boats used to be big outboard two strokes and would run a mix of not less than 40:1 but thats a while ago. They are all now 4strokes and any \'R\' in trhe petrol would be there as a \'ucl\' to lubricate the valves and seats and would be at ratios a lot higher than 125:1

[Jono FD3]

the F1 power boats used to be big outboard two strokes and would run a mix of not less than 40:1 but thats a while ago. They are all now 4strokes and any \'R\' in trhe petrol would be there as a \'ucl\' to lubricate the valves and seats and would be at ratios a lot higher than 125:1

You ar correct there Bob, the off shore boats are all inboards (or mostly) and 4 stroke, but the circuit F1 powerboats are still using the Mercury 2.5 V6 EFi 2 strokes sound awsome but the porting has been taken to the extream now as they are machining outside the standard castings & building the block back up with some sort of chemical metal stuff!! the ports are starying anythin up to 3/4 of an inch outside of the std castings :2eek

Jono

[Bob Monkhouse]

Would that be for the transfer ports?They are probably using \'Devcon\' or something similar. I used to use it at one time but went to ally welding the casings up as it doesn\'t tend to fall out. One of the common things I used to do was weld the boost port holes up in reed valve pistons and then lap them back in for use in piston ported engines. Japanese (A.R.T) pistons are 20%silicon and don\'t tend to seize easily(unless you use the cheap .... recycled chip oil masquerading as two stroke you get at petrol stations)!! They also have 1mm -and less -rings made from cold drawn wire, you don\'t get ring flutter with them and in some of the road bikes I have done they will do 10,000miles fairly easily. Some of the kart engines I\'ve done are using a ring a race!!

[Jono FD3]

Devcon dose seem to ring a bell actualy..... Not sure where the machining was done inside the block as the power heads I worked on were fully asembled, but still needed the intake & electrical systems fitted!! the Devcon was on the inlet & exhaust side of the cylinder bore, running all the way yp to where the ports enter the combustion chamber.

Jono