Hi I am a newbie (retired-Accountant) .... so treat me gently pls.
Was at a tipshop last week and my wife bet me I couldn't get an old mower to work .... So for $10 we lugged it home. The challenge was on.
It's a 1997 Rover Sprint 375 with a B&S.
No starter rope. Plastic bag & rope remnants around shaft. No foam air filter No sign of external oil. Blades were connected upside down (nuts to the bottom) Inside oil was very "gluggy" and very low. Been in the elements as it is a bit rusty.
So far I have : 1) Drained oil - very little came out - filled with new oil 2) Cleared the shaft & taken blade carrier & blades off. 3) Cleaned out fuel tank & new fuel 4) Checked the carby & cleaned it without dismantling 5) Governor springs appear to be connected incorrectly - Did not change anything 6) Ordered new plug, air filter & blades as a package deal.
Then tried to start it & voila, IT RAN.
BUT .....
It run like it was ready for takeoff - really. really loud & high. And plenty, plenty, plenty of white smoke !!!! I turned the mower off after one minute.
And then I checked the mower for any oil leaks (top & bottom) - No sign of any leaks around engine or underneath cam seal. I then checked the oil level & it seems below the "low" level.
So whats next ?
Is it worthwhile to continue or are the signs not good ?
If it is not terminal, I thought : Start at the carby, dismantle & new diaphragm Fit the new blades Maybe put some "Nulon Engine Oil Flush" to flush the old oil sludge.
All up, a great learning experience so far & a bit of fun.
Any ideas ......... (don't tell my wife I am getting outside assistance) ?
You got it running, game over and collect on the bet !
When you day loud is that knocking loud ? might need to adjust the governor spring tension if the throttle control isn't adjusting revs. Check the throttle cable adjustment as well. If the mower hasn't run for a long time it's not uncommon for the smoke to clear after running for 10 mins or so ( if the engine is ok ) What grade of oil did you put in ?
You got it running, game over and collect on the bet !
When you day loud is that knocking loud ? might need to adjust the governor spring tension if the throttle control isn't adjusting revs. Check the throttle cable adjustment as well. If the mower hasn't run for a long time it's not uncommon for the smoke to clear after running for 10 mins or so ( if the engine is ok ) What grade of oil did you put in ?
I never thought that "getting it to work" would be a winning bet. Put it on the wife & she has redefined the bet to be ... "Cutting the grass ..... With those fancy green stripes as well, and .... Trimming the roses as well" Nuff said.
When I got it to run, the sound was just very loud. No obvious knocking (or smashing or crashing). Just revving very high. That's why I thought the carby cleanout would be the next priority. And the governor springs.
The engine oil I put in was SAE30. Will the mower & new oil clear out the sludge by itself (via smoke) or will I need something else to flush it out ?
BTW, the mower is at my daughter's house (She has space under her house for storage/workshop), so it will be a few days before I can get pictures or do the next steps.
If there is something more sinister to the mower, what should I look for ? Oil leaks somewhere ? Knocking ? I have read that head gasket / rings / etc could be a problem but there is no way I am up to those at the moment. Just on a steep learning curve.
It seems like these old mowers are indestructible after all the poor treatment this old one has obviously taken. Research indicates this one was made in Eagle Farm, Brisbane.
Hard to win footy matches when the goal posts keep shifting. Sounds like the wife is sweating ever so slightly.
I wouldn't bother doing anything else until the revving is sorted out and go from there depending on your plans for it. Sounds like it has been tinkered with and it's not unusual for people to tip them too far onto their side resulting in some oil getting into the exhaust, hopefully that's all it is and it will burn away.
SAB, Welcome here you are on the right track. With the revving problem and the air filter off you can see the governor arm on the end of the spring and if you push the arm to the left it will decrease the revs, if you stretch the spring slightly you will see that the revs drop so you can work around that point. Did you get it started using the primer and if you did then leave the carby alone it is working fine. If you start it up and run it several times there is a good chance the smoke will clear, the problem it quite often happens
A warning; Sometimes you will find these stall after 5 minutes due to dirt in the carby/clogged pick up pipe. So don't go in and drag her out to say its running right and then have it stall 3 lines into the lawn (could be embarrassing haha).
With regard to oil flushing, if you have 50ml of the nulon you want to get rid of, use it. I have a bottle I got included with a bottle of oil at repco in a combo deal and have used 50ml in a briggs. Does ok.
I personally go down to Autobarn and get the cheapest 15w40 oil on special – the nulon or gulf western $10/5l
Run that through several times – maybe run 15 mins, change, then another 30 minutes and change. Eventually it will stay clear.
Definitely post a picture of the springs – probably the problem
Congratulations on getting it running – you are well ahead of some guys
I overheard a conversation in repco on Saturday – a newly retired guy wanted to change the oil in his car for the first time in his life. He was enlightened by the employee that the numbers on the front of the oil bottles is how thick the oil is
So I will start at : 1) Put new blades on (maybe running with no blade carrier is not so good for the engine and contributes to the high revving) 2) Governor Springs to bring revs down 3) Let it run for several minutes & observe white smoke (hopefully disappearing) 4) Few oil flushes with some year old 10W50 motor oil I have left over from last year 5) If need be, then the carby gasket/diaphragm
Wife now wondering if I can turn her old barrel vacuum cleaner magically into a Dyson stick vacuum. What have I created ?
Off topic, but the Dysons are amazing. On the first use, you will fill the 'bag' barrel in 10 seconds flat, especially if the barrel vac is over 15 years old.
Yes NormK, I found that out the hard way. I have a Masport that was given to me because it would not run, an extremely clean mower with catcher, investigating I found the carby/governor spings etc all fitted incorrectly and the key for the flywheel did not exist. One of the fisrt things I do when I bring a mower home is pressure wash it completely before taking the engine off, when pressure washing under the mower I noticed the cutting disc moved, it was cracked and when I went to have a look fell of in my hand so imagine the mower was pulled apart to find the noise. As I collect older mowers and advertise for freebies I do end up with some mowers that are not what I call collectable but too good for scrap, so have been doing them up to go to my local mens shed for them to raise funds or to donate to a worthy person. Got off the track here haven't I, anyway got the motor all back together and mounted and went to start it not once but bloody twice. my right hand was in pain for over a week lesson learned, still have not started the Masport yet as am waiting for a donor mower to get the disc off. Beech
Hi Beech, Most Masports I come across have the cracked blade carrier. I weld the crack on both sides and then weld a big washer over the center. That seems to fix the problem as none of those have given trouble again
Photos of current Governor Springs.- Any ideas pls When the mower runs (v high revs) there is no movement in the springs - They still remain completely slack.
Looking at the pictures the small spring needs to be connected to the tab and look like the linkage end, no big deal. In the pictures you can't see the linkage end inserted right through the vane arm so the arm sits in the elbow of the linkage. I have attached a couple of pics of a 450 series set up which would be very similar and you can see the end of the vane arm with the linkage through it. If the linkage isn't fitted correctly you'll need to do this first. First pic is in stop position, second full throttle. Like Tyler asked, can you move the throttle linkage from stop to full without any restriction ? Your's might be jammed ? Might pay to connect the throttle cable and adjust it then compare the pictures when you operate the throttle, looks like your pics are in stop position and the governor tab looks like it has already been bent to its lowest point.
SAB, no way that throttle will work as it is, get the quadrant to the stop position, make sure it is touching the kill switch pin, then open the throttle just away from the kill switch and see what the revs are like. At this stage I would disconnect the small spring as it is only adding to the confusion
What I did : 1) New blades onto blade carrier then onto mower - (thx normk) 2) Looked at governor springs - It appeared that the black butterfly clip was only in "full on" or "full off" positions - no freedom of movement between - Then took the top off to look at the vane - It too would only be at "full on" or "full off" - Took the vane off and cleaned & lubricated it (WD40) - there was heaps of dust/dirt around & in it. - Then reconnected to throttle/governor spring linkage - Now it has full freedom and "jiggles" around nicely. Must have been jammed somewhere (thx wce). 3) While toggling the linkage, the small governor spring broke off at the end (rust?) - I refashioned the end & reconnected - I also moved the "lug" for the idler spring back to a more upright position (thx Tyler) 4) Oil topup & started - WOW - SUCCESS !!!!! - Small amount of smoke for about 2 minutes & idleing was beautiful. No obvious knocking. 5) To get rid of the black oil, then did 3 oil changes (cheap year old 20W50) with 10 minutes static running between each change. Butterfly clip could be moved easily while running. Oil was "clearish" after the third run - Finally, put in SAE30 oil - (thx Tyler again) 6) Air Filter on, throttle cable reconnected, then mowed the 400sqm lawn (45 mins) to impress my wife. 7) All the time the low revs were beautiful and still no obvious knocking, but it would not rev to the high end. Felt it was revving about 75%. May struggle in really thick grass but not a problem for me at the moment. Checked the big governor spring & it was still slack even when throttled up fully. I will play with this big spring in my next chapter. I feel more confident in them now and might even get new ones for a few bucks. 8) No obvious problems with surging or hunting so left carby alone - Also no signs of kickback (thx normk) 9) Got standing ovation from my wife & daughter.
Still very impressed with the builds of these old mowers (23yo). If only my dishwasher, or washing machine would be the same.
All up, the learnings for me have been fantastic & all your ideas were of great assistance. Without them I would be still fumbling around, doing unneeded stuff and not doing the needed stuff. Swearing a lot, and maybe even hurting myself.
AND I WON THE BET !!!! Will collect from my wife tonight after the football.
That's great news, it's amazing how many of these nice older models can be put back into service for many years. A bit of annual maintenance is all thats required really but people think they don't need servicing because it still starts and runs ! A lot of the same folk will buy an expensive new car and have it serviced religiously at a huge expense even though modern cars have a lesser amount of service requirements than older models.
all you need to do to get your required full revs is to set the throttle lever in the full run position with the mower running ( presuming the cable is correctly adjusted ) then bend the tab that the main spring is attached to outwards until you have what you think is a good amount of revs for what you want to cut without going overboard, as you have seen, these little engines are subjected to ridiculous amounts of unnecessary pain but some how manage to cope.
Well done and collect well on the bet ! nudge, nudge, wink, wink, no need to say anymore eh Guvnor !
