Originally Posted by
apereira
Hi Dave,
The fact the piston and liner are aluminum/chrome is no surprise as it is the most used combination for piston engines, from RC to full scale aircraft piston engines, but backwards, where the piston is steel; An aluminum body is easier to manufacture and it is lighter, but I do think the grooves in the piston might be all that was needed to solve the situation you had, how many flights did you have on that pump? 600+?
I fully agree with you about the oil, I still run 23% oil and never had problems, but no Castor, castor in this pumps is a killer if you let the engine sit for a while, my engine was in a bag for over a year, and the old fuel stained the piston, now that I took the pump apart to take a picture for you is when I realized if I want to store this engines, it is better to take the pump apart completely, clean it and lube with a light oil. Personally a have been using 3 in 1 since I was a kid and started on Rc with great results. What do you think?
The 185 is identical to the 170 and it's predecessors, exact same dimensions and physical appearance, the only way to tell which is the 185 is on the pump, the reference pressure hose it is not used anymore, look at the picture I previously attached, apart from that, like with previous models it is a bolt on replacement.
Best regards
Alejandro
Less than 50 flights....and I flew the second pump perhaps 5 times because this second pump fixed the first problem but brought a second problem with it that I could not fix in spite of replacing everything there was to replace.
For the past 8 years or so I have been using Castrol synthetic motor oil for after run and storage oil. I have several engines stored in plastic bags after using a considerable amount of oil....they are still perfect after several years,
Previously, I had been using air conditioning or compressor oil which is similar and works well also but the Castrol is much easier to get at Walmart or any auto parts house.
This is not a petroleum product....I use the thinnest weight...cant remember exactly right now....but it is very similar to the oil we use in fuel.
When I get home after every session I put a considerable amount in the intake then spin the engine.....right side up.
This oil has worked better than any other oil I have tried except castor which of course as you mentioned above...will cause other problems.
Because it is synthetic there is no problem starting the engine next time out......or 2 years later.
Try it.....but use more than a few drops....I probably use an ounce after every session...it is odorless so it does not stink up the shop!
Thanks again Al.....
Dave