Roto-start question
10-03-2006, 10:19 PM
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Roto-start question
So I turn my savage x stock engine off the other day, and then about a day or so after put some after-run in because I realize I wont get back to him for a while.
I try to turn a bit with the roto start drill to get the after run all over. But i get no compression or turning of the engie. I worry and pull out the engine and take off the roto-start gearbox to see if anything is noticeable wrong. (its the first time i've ever taken that off so I don't know for sure what I'm looking for, but think I would notice if it was really screwed up).
Anyway, i don't see anything, put it back on to check and the drill compresses it no problem, so i tighten to gearbox back down.
Does anyone have any ideas why it wouldn't the first time. I tried it 3 or 4 times but didn't want to do it more for fear of further damage. Is this a sign my rotostart is going out? or just a weird fluke? Any ideas would be appreciated thanks
I try to turn a bit with the roto start drill to get the after run all over. But i get no compression or turning of the engie. I worry and pull out the engine and take off the roto-start gearbox to see if anything is noticeable wrong. (its the first time i've ever taken that off so I don't know for sure what I'm looking for, but think I would notice if it was really screwed up).
Anyway, i don't see anything, put it back on to check and the drill compresses it no problem, so i tighten to gearbox back down.
Does anyone have any ideas why it wouldn't the first time. I tried it 3 or 4 times but didn't want to do it more for fear of further damage. Is this a sign my rotostart is going out? or just a weird fluke? Any ideas would be appreciated thanks
10-03-2006, 10:39 PM
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RE: Roto-start question
It may have had too much compression to turn over. With no compression, it would spin easily. The piston could also have been at or near top dead center where it is the hardest to turn. Next time, try taking the glow plug out first and see if it's easier to turn over. That usually does it.
10-03-2006, 10:45 PM
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RE: Roto-start question
It's probably the OWB (one way bearing). They tend to collect oil and will start to slip. If the engine stops with the piston at or near TDC and you have a slippy OWB then it's possable that it wont turn the engine over. OWB's slipping is a pretty common problem and a good cleaning usually fixes the problem. If the engine is older then it's posable that the OWB or maybe the shaft it rides on is wearing out but you really have to have a good bit of runtime before that becomes a problem.
On a related note, be sure that you get the clutch bell/spur gear mesh right when you reinstall the motor.
On a related note, be sure that you get the clutch bell/spur gear mesh right when you reinstall the motor.
10-03-2006, 10:57 PM
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RE: Roto-start question
actually i did take the glow plug out to try running it that way, but same result, that's when i took the engine out of the car to look at,
about the OWB, is there a good place I can go to to learn more about that, i'm not very familiar with it
about the OWB, is there a good place I can go to to learn more about that, i'm not very familiar with it
10-04-2006, 07:57 AM
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RE: Roto-start question
Well, a search here on RCU (or any other site for that matter) willl give you tons of results.
A quick overview...
Every engine that has a pull start or a powered start has a owb. Bump starts or other systems that directly turn the crankshaft don't need or use them.
A owb is a bearing that is designed to grip a round shaft when it is turned in one direction and freewheel in the other. That allows it to grab the crankshaft to start but just spin once the engine starts. The owb is usually pressed into a housing (like a hex shape) so that the starting system can grab it and and turn the engine. Owb's are usually installed w/o any lube as you want it to grip the shaft it's mounted on. They do perodically collect excess oil and dirt and start to slip. Dissassembly and cleaning will usually fix the problem. Sometimes though, the housing they are pressed into will crack and the whole bearing will have to be replaced. Also sometimes the bearing and haft will wear over time and have to be replaced.
Some people who experence chronic slipping have drilled small holes into the backplate in order to be able to spray WD-40 in to clean the bearing w/o having to remove it. Another trick to help improve grip is to lightly sand the shaft that the owb rides on with very fine grit emory paper.
Hope that helps some.
A quick overview...
Every engine that has a pull start or a powered start has a owb. Bump starts or other systems that directly turn the crankshaft don't need or use them.
A owb is a bearing that is designed to grip a round shaft when it is turned in one direction and freewheel in the other. That allows it to grab the crankshaft to start but just spin once the engine starts. The owb is usually pressed into a housing (like a hex shape) so that the starting system can grab it and and turn the engine. Owb's are usually installed w/o any lube as you want it to grip the shaft it's mounted on. They do perodically collect excess oil and dirt and start to slip. Dissassembly and cleaning will usually fix the problem. Sometimes though, the housing they are pressed into will crack and the whole bearing will have to be replaced. Also sometimes the bearing and haft will wear over time and have to be replaced.
Some people who experence chronic slipping have drilled small holes into the backplate in order to be able to spray WD-40 in to clean the bearing w/o having to remove it. Another trick to help improve grip is to lightly sand the shaft that the owb rides on with very fine grit emory paper.
Hope that helps some.
