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Message |
    
dave chattaway
Member
Username: dchattaway
Post Number: 8
Registered: 04-2008
| | Posted on Saturday, June 28, 2008 - 04:27 pm: | 
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I got my engine working now, but it doesnt like to idle it seems to almost die then rev its nuts off. also find its hard to start when hot and when running in gear it will fluctuate between running sweetly at half rev to idle to very fast then back to idle(without touching throttle) obviously things to check would be float and carb but these are clear and fine, so any suggestions would be appreciated.
it is extremely reliable in the sense that it hasnt died on me once (in maybe 10 hours use this year) but cant manage trottle most of the time.
p.s. is it normal for an m3 to vibrate a lot or are they generally smooth runners.
cheers |
Peter Ogborne
Senior Member
Username: peterogborne
Post Number: 264
Registered: 09-2002
| | Posted on Monday, June 30, 2008 - 06:22 pm: |
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Sounds like carburetor problems Chris .I would take it to pieces and make suer everything is OK ,all jet clear and this goes for the fuel line as well .Also check that the breather hole in the fuel tank cap is not blocked.
Your R3 engine should run very smoothly at low and maximum revs. |
dave chattaway
Member
Username: dchattaway
Post Number: 9
Registered: 04-2008
| | Posted on Tuesday, July 01, 2008 - 02:10 pm: |
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as noticed in another post, have adjusted the spark plug gap a little smaller. This has completely sorted the problem of starting when hot. it starts everytime with half a flick on the handle.
went diving under the boat with a snorkle and found a large clump of weed wrapped around the prop. Cut all that off and lo and behold, i can finally get full power and maximum revs. Woohoo.
However-it will idle in gear ok and everything in between but as soon as you put it in neutral the revs build and build till its screaming.
I can use this lovely engine ok and am getting each thing sorted, slowly but surely. just this last little niggle now!!! Phew |
dave chattaway
Member
Username: dchattaway
Post Number: 10
Registered: 04-2008
| | Posted on Tuesday, July 01, 2008 - 02:12 pm: |
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P.s.
Thanks peter, have checked all jets, line etc it is all clear. will keep trying |
frances Goble
Visitor
| | Posted on Saturday, August 02, 2008 - 08:04 am: |
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My R3M has the amal 396 carb and once warm ticks over quite smoothly . Tickover is easy to adjust with the throttle valve stop scew . As you turn this anti clockwise you can see the pivot to which the throttle valve is attached closing so decreasing revs. Check the linkages to the throttle lever are adjusted to allow this movement to occur. Spark plug gap is critical on these engines keep it as recommended around .016". Even flat out (1500rpm) its quite smooth, however I have seen a poorly installed engine shaking around pretty badly due to flimsy bearers with flex created even in the hull bottom boards.
Hope this all helps . ( I have the original instructions for the amal carb adjustments if you need a copy .) |
Kent H Smith
Member
Username: kent_smith
Post Number: 12
Registered: 10-2004
| | Posted on Sunday, August 03, 2008 - 05:41 am: |
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Frances, I have an R3M in a wooden clinker boat. The boat has solid timber engine mounts. The engine is smooth at low revs and at full throttle but some vibration at medium to 3/4 throttle. Any thoughts?
Also could you or other R3M owners tell me best spark plug for the R3M? I have been using NGK B5HS and NGK B7HS with .016 gap. They seem good on longer runs. (the B7HS better when the engine is hot and running at full throttle), but prone to fouling on short runs or on first start up. |
frances Goble
Visitor
| | Posted on Monday, August 04, 2008 - 07:25 am: |
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I find the NGKBP4HS gives excellent results. It has a longer protruding central insulated core which places the spark further into the combustion zone and according to the technical data on plugs, runs abit hotter. This with premium unleaded, modern 2 stroke oil and a mixture of up to 55:1 seems to reduce the oiling up problems quite well. I don't think you can ever eliminate this feature of the R3M , I can remember as a child 40+ years ago (same engine and boat but alot newer!) my dad on many occassions whipping out the plug to replace with a fresh clean champion plug!
Concerning the vibration at certain rpm's , a single cylinder engine with no counter balancing devices will generate vib's as harmonics reach certain points . Cruising ,I take it up to max rpm then back it off slightly, recently travelling 70kms up the Glenelg river in Victoria , Aus without any problems. |
Kent Henderson
Visitor
| | Posted on Wednesday, August 06, 2008 - 08:48 am: |
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Thanks Frances. Will try the NGK4BHS. You say it runs a bit hotter. How hot does the top of the cylinder head on your engine get on long runs? I'm never sure whether my engine is running too hot or too cold. I can touch the cylinder head near the brass dome nuts, for about a second or so when its up to full temperature.
The Stuart R3M certainly runs better when I am giving it regular long runs. Half hour or more. |
frances Goble
Visitor
| | Posted on Wednesday, August 06, 2008 - 07:16 pm: |
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Kent, the NGK plug I use is the BP4HS which in my experience is less prone to oiling up than the B5HS ( I think largely due to its slightly longer central core).
The Temperature you describe sounds normal. Running up the river recently (our winter) with the air temp. at 12C and water temp around the same the engine definately feels cooler and the outlet water temp , compared with running in summer with air temp 30C + and water temps in the low 20's. Water outlet is then almost too hot to keep hand under for long.
It doesn't seem to make any difference with the engines performance though. |
kent henderson
Visitor
| | Posted on Friday, August 08, 2008 - 06:53 am: |
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OK thanks Frances. will definitely give BP4Hs a try. Is Glenelg river worth a visit. I've been told the banks are quite steep and not many places availfor easy stopping and stepping ashore? |
David Stott
Member
Username: david_stott
Post Number: 29
Registered: 06-2005
| | Posted on Monday, August 11, 2008 - 10:11 pm: |
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Glenelg river is a great place to cruise. Deep still water, with plenty of landings, even camping areas if you want to stay overnight along the way. |
frances Goble
Visitor
| | Posted on Tuesday, August 12, 2008 - 08:56 am: |
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The Glenelg River is definately worth visiting. We've Kayaked it three times with young kids and in March 08 took our R3M powered boat for a run launching from Dry Creek ( good boat ramp ) and camping at Georges Rest for a couple of nights with trips further up from there. You need to book camps with the Nat. Parks Office at Nelson although outside school hols. you'll only see the odd fishing boat. There's several pull out points up the river if Stuart reliability is an issue and maps can be got from the Parks office. Definately worth visiting! |
