feetupfun Posted September 17, 2009 Report Share Posted September 17, 2009 I will also find a condenser and replace it although I don't see how that can be the problem since I'm getting spark at the plug. Any more ideas? The reason why the condenser may be the problem is that you are checking the ignition timing by measuring when the points open, while the timing of the spark at the plug can be quite different to when the points open if the condenser is not working. Reasons for why the motor may not be sucking enough air are most commonly the rubber tube between the carby and barrel gets a split, crankshaft seals leaking or blown cylinder base gasket. Quote Link to comment Share on other sites More sharing options...
motovita Posted September 17, 2009 Author Report Share Posted September 17, 2009 The reason why the condenser may be the problem is that you are checking the ignition timing by measuring when the points open, while the timing of the spark at the plug can be quite different to when the points open if the condenser is not working.Reasons for why the motor may not be sucking enough air are most commonly the rubber tube between the carby and barrel gets a split, crankshaft seals leaking or blown cylinder base gasket. I believe that is in fact my problem(the condenser). When I removed the condenser I found that the case is cracked. Now my problem is finding a suitable replacement. Does any one have a part number or application for a commonly available condenser? The local parts store is little help unless I can tell them what car I want a condenser for. Quote Link to comment Share on other sites More sharing options...
wayne_weedon Posted September 17, 2009 Report Share Posted September 17, 2009 Would depend where you are I guess. I have found these simple ignitions are not too fussy about the actual capacitance of the condensor as most are similar values. Try to find one that can be fiited easily for a start. Wayne.... Quote Link to comment Share on other sites More sharing options...
big john Posted September 18, 2009 Report Share Posted September 18, 2009 I believe that is in fact my problem(the condenser). When I removed the condenser I found that the case is cracked. Now my problem is finding a suitable replacement. Does any one have a part number or application for a commonly available condenser? The local parts store is little help unless I can tell them what car I want a condenser for. Try Hugh's Bultaco if you are in the USA http://www.bultaco.com Big John Quote Link to comment Share on other sites More sharing options...
motovita Posted September 18, 2009 Author Report Share Posted September 18, 2009 I am in the USA. The other side from Hugh's Bultaco though. I bought a common automotive condenser rated at .18-.23 mfd. The condenser I replaced was large (2 to 3 times the size of the automotive condenser I replaced it with), brass cased, and had a threaded stud rather a wire protruding from it. It is made by Mallory in the USA. and has only a #36 on the bottom of the case. The bike still will not start! I rechecked the static timing, it's fine. The spark at the spark plug gap is visibly different between the two condensers. With the new part the spark is smaller (not unreasonably so) but more consistent. With the old condenser reinstalled the spark is quite fat but seems like it might occasionally skip a beat. The engine does pop and try to fire more with the new condenser. It's Friday and the Trial is Sunday, Any suggestions would be greatly appreciated. Today I will try some ether in the intake, out of desperation. Quote Link to comment Share on other sites More sharing options...
motovita Posted September 18, 2009 Author Report Share Posted September 18, 2009 I just got off the phone with Mallory. A tech identified the old condenser as their part # 25010, which is of course, no longer available. The #36 on the bottom indicates .36 mfd. They do have a current condenser with that rating #28005a. I'll try to find one. He told me that the 25010 was popular with bike guys and that it was common for the case to crack and leak the fluid out. He said the bike guys thought that the larger condenser made the bikes easier to start. Quote Link to comment Share on other sites More sharing options...
gomey68 Posted September 18, 2009 Report Share Posted September 18, 2009 Just to add my 2 cents :-) If the bike has spark then it should fire to "some degree". if it doesnt fire then either the timing is wrong (which you have checked) or one of the other essentials is missing i.e. fuel, compression, crankcase pressure. The first thing I would check is the woodruff key on the flywheel and also the main seals on both sides of the crank. Both are easy to check. Hope i didnt repost what some else had suggested : Where on the West Coast are ya?? Quote Link to comment Share on other sites More sharing options...
wayne_weedon Posted September 18, 2009 Report Share Posted September 18, 2009 We had suggested crank seals, and I'm still rating that as a top contender for the fault. Easist way to verify it could be the problem is a thimbles worth of fuel down the plug hole and then try to start it. if it fires and runs for a second or two then its almost certain to be the seals especially if the carb has been proven to be all ok. Wayne.... Quote Link to comment Share on other sites More sharing options...
big john Posted September 18, 2009 Report Share Posted September 18, 2009 After the 19th section as I rode slowly between sections the bike died as if running out of fuel or fowling a plug, not a clean cutoff like hitting the kill switch but a brief on/off, trying to stay running before dieing for good. Yip strange indeed, every time those exact symptoms happened on my model 80, 250 Sherpa when I rode it almost every weekend in life (long time ago), those symptoms usually ended up with me changing ignition side crankcase seals! Big John Quote Link to comment Share on other sites More sharing options...
bultaco49 Posted September 18, 2009 Report Share Posted September 18, 2009 Hi - just in case you need some other theories there is a US based Bultaco forum which has a very similar thred in the index. Its here - http://forums.delphiforums.com/bultforum/m...ges/?msg=4280.1 I'm with Wayne on this one. Change the crank seals! Its an easy job (as they are in holders on the outside of the crank case) and as the bike has sat around they probably could do with changing anyhow. Quote Link to comment Share on other sites More sharing options...
stork955 Posted September 18, 2009 Report Share Posted September 18, 2009 Gday, a couple of thoughts in addition to all those above. Your .36 mfd capacitor (are you sure its mfd's not ufd's?) would be available from any electronics store - get as high a voltage one as you can (there are ones that are suitable for up to 600 v). You need an electrolytic type, but dont get a polarised version. The value is important so get as close as you can. Very cheap ($1.00) to try. Recheck your timing - were you checking in the correct direction of rotation? An easily made mistake that can put your timing out 20 degrees or more - enough to cause problems. Also try starting the bike with exhaust removed. If it runs it will be loud,but at least you will eliminate this as a possible source of your troubles. Costs nothing to try! Its important that you do one thing at a time so you know what is actually giving you trouble. If that doesnt work go back to your starting point before attempting something else. Cheers, Stork Quote Link to comment Share on other sites More sharing options...
swooshdave Posted September 19, 2009 Report Share Posted September 19, 2009 NAPA # 7-01338 Quote Link to comment Share on other sites More sharing options...
motovita Posted September 19, 2009 Author Report Share Posted September 19, 2009 (edited) Gomey68- I'm Jeff from Spokane I ride a couple of PST events a year. Last one was the PNTA at Gold bar, and yes the flywheel key is fine. I've tried the fuel down the plug hole, didn't help. My method of checking crank seals is to remove the carb and hold my hand against the intake boot while cranking. The compression stroke pulls my hand hard aginst the rubber boot and holds it there and the first part of the power stroke, before the intake port closes blows my hand off. I don't mind changing crank seals but I don't feel they are my immediate problem. Stork955- You must have much better electronics stores in Australia than we have here. A request for a .36 uf capacitor here will most often get you no more than a blank stare. I've always used uf for microfarad since that is how I've seen them marked but in the auto parts catalogs here they are using mfd. Yes I've got the rotation correct and I do have the muffler removed. So now for the latest. I decided to rewire the ignition as it has been redone in an unusual manner, (but it ran fine). While I was doing this the primary coil went open (over 2k ohms)and has stayed that way! So maybe this is good and I had a partial or intermittent problem there before, or maybe my handleing of the assembly caused the failure and I still have the original problem to deal with. In either case I will try to find a replacement. Can someone tell me the test spec. for the primary coil, so I can at least make sure I put in a good one? Thanks for all the input. Edited September 19, 2009 by motovita Quote Link to comment Share on other sites More sharing options...
wayne_weedon Posted September 19, 2009 Report Share Posted September 19, 2009 Certainly a mystery, especially as Bultaco's are most often 1 or 2 kick starters with certainty when properly setup. Did the engine not even fire when you put a little fuel down the plug hole? Wayne.... Quote Link to comment Share on other sites More sharing options...
motovita Posted September 19, 2009 Author Report Share Posted September 19, 2009 (edited) I've tried it several times. Sometimes I get a pop or two sometimes not and yes before the bike died it was a consistent two kicks cold, one kick warm starter. Also I've not mentioned that there is no rust and very little dirt under the mag cover. Today I will double check the primary coil and try to find another one to install. I found a spec. for the primary coil on another forum of 2.5 ohms(Thanks to Bultaco 49). This seems low to me can someone confirm it? Edited September 19, 2009 by motovita Quote Link to comment Share on other sites More sharing options...
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