smokinrider
Husqvarna
A Class
I have just added a 250 xlite to the collection. it had a starter issue where the estart would crank it to TDC and not be able to overcome the compression. Started fine on the kick but hey thats not why i buy an estart bike!
Having read all the threads on starter issues, battery issues, incorrectly lined up/mismatched gears etc i was horrified to think the repair was going to be expensive. i had checked the volts and the battery was a little low 12.3v and dropped to 6v when cranking.
OK
Back to basics. With the plug removed to remove the compression i cranked it over. the starter flew round and turned the engine with ease. Interesting, so its not the starter or the gears as they all seemed to sound and work ok.
Lets check the decompresser mechanism, flicked it with a screwdriver and it all worked ok not siezed and looking in good order. HMMM
NOW check the valve clearance for the valves. inlet both ok at 0.15mm exhaust (kick start side) ok at 0.20mm generator side**************************************** wooooooo 0.36mm way to huge. so huge the decompressor lobe cannot hit the bucket and open the valve. cam caps off noting bolt locations, cam removed and lobe height checked (no wear) bucket and shim removed and replaced with 0.16 bigger shim than in it original.(advantage of a full set of hot cam shims, 3 of everything from 1.2mm to 3.5mm in .05 increments) dob of moly grease on lobes journals etc and reassemble making sure not to over tighten cap bolts (at 4ftlb it would be impossible with anything but the best torque wrench so use your noddle, 4ftlb with a 3 ft 1/2 inch drive breaker bar designed for truck wheel nuts aint gonna do it!! my 3/8 drive inch pound torque wrench only went down to 10ftlb.
Whilst cam off checked other exhaust valve and shim.
Comparing the loose tappets shim with the correct other side i noticed there was exactly 0.16mm difference between the 2 shims. it is possible someone has dropped a ball in the past and replaced shim with one way too small and not noticed. Its possible they had changed shim and it hadnt seated properly giving false reading and then over compensated? due to the design of the head some larger width feeler guages do feel tight even though they are not anywhere near the correct thickness for the clearance. think this is due to the castings of the head getting in the way and putting pressure on them.
Way hey problem solved. no expensive starter motor or gears to buy.
Its possible that with a lazy decompressor due to a large clearance on this 1 valve that this is what is knackering peoples batteries and starters by trying to wind over an engine without enough decompression.
Just a thought.
CHECK THE BASICS BEFORE STRIPPING YOUR ENGINE AND SHELLING OUT £100's on starters or gears****************************************
Check your valve clearances carefully and regually. And always measure twice or three times after engine has been wound over 2 or three times inbetween checks to ensure all is correctly seated and timed.
Anyway my bargin 10 plate te 250 with 1800 miles for less than an 04 plate!!!
Having read all the threads on starter issues, battery issues, incorrectly lined up/mismatched gears etc i was horrified to think the repair was going to be expensive. i had checked the volts and the battery was a little low 12.3v and dropped to 6v when cranking.
OK
Back to basics. With the plug removed to remove the compression i cranked it over. the starter flew round and turned the engine with ease. Interesting, so its not the starter or the gears as they all seemed to sound and work ok.
Lets check the decompresser mechanism, flicked it with a screwdriver and it all worked ok not siezed and looking in good order. HMMM
NOW check the valve clearance for the valves. inlet both ok at 0.15mm exhaust (kick start side) ok at 0.20mm generator side**************************************** wooooooo 0.36mm way to huge. so huge the decompressor lobe cannot hit the bucket and open the valve. cam caps off noting bolt locations, cam removed and lobe height checked (no wear) bucket and shim removed and replaced with 0.16 bigger shim than in it original.(advantage of a full set of hot cam shims, 3 of everything from 1.2mm to 3.5mm in .05 increments) dob of moly grease on lobes journals etc and reassemble making sure not to over tighten cap bolts (at 4ftlb it would be impossible with anything but the best torque wrench so use your noddle, 4ftlb with a 3 ft 1/2 inch drive breaker bar designed for truck wheel nuts aint gonna do it!! my 3/8 drive inch pound torque wrench only went down to 10ftlb.
Whilst cam off checked other exhaust valve and shim.
Comparing the loose tappets shim with the correct other side i noticed there was exactly 0.16mm difference between the 2 shims. it is possible someone has dropped a ball in the past and replaced shim with one way too small and not noticed. Its possible they had changed shim and it hadnt seated properly giving false reading and then over compensated? due to the design of the head some larger width feeler guages do feel tight even though they are not anywhere near the correct thickness for the clearance. think this is due to the castings of the head getting in the way and putting pressure on them.
Way hey problem solved. no expensive starter motor or gears to buy.
Its possible that with a lazy decompressor due to a large clearance on this 1 valve that this is what is knackering peoples batteries and starters by trying to wind over an engine without enough decompression.
Just a thought.
CHECK THE BASICS BEFORE STRIPPING YOUR ENGINE AND SHELLING OUT £100's on starters or gears****************************************
Check your valve clearances carefully and regually. And always measure twice or three times after engine has been wound over 2 or three times inbetween checks to ensure all is correctly seated and timed.
Anyway my bargin 10 plate te 250 with 1800 miles for less than an 04 plate!!!