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Will750 09-29-2019 07:38 AM

At withs end with this bike
 
Hey guys as most of you no i had a starting problem after the engine rebuild. It turns out the timing was off. So timing has been adjusted to a T. Carbs cleaned, plenty of fuel. Plenty of spark. Battery fully charged even tried jumping it off a freshly charged car battery and still wont start. All connections checked and rechecked. All grounds sand shiney and tightened. Still nothing. It wont even fire with starter fluid. Its cranks and cranks but just wont catch. Anyone on here got any ideas on what could cause this. Everything is working as it should. Im at breaking point with this and im close to parting it out.

TonyO 09-29-2019 10:23 AM

Are you sure about the spark? it might be good in open air but it is it good under pressure in the chamber? Do you have a way to check ignition timing?

Spockster 09-29-2019 11:23 AM

Was it the cam timing?

Agree about the spark and pressure. What color is the spark?

Maybe a compression check? Seems that with everything there, you should get at least a nice ka-boom once in a while.

No rats nest, or air filter foam, blocking the air intake?

Will750 09-29-2019 11:29 AM

Quote:

Originally Posted by TonyO (Post 1280255)
Are you sure about the spark? it might be good in open air but it is it good under pressure in the chamber? Do you have a way to check ignition timing?

Quote:

Originally Posted by Spockster (Post 1280263)
Was it the cam timing?

Maybe a compression check? Seems that with everything there, you should get at least a nice ka-boom once in a while.

No rats nest, or air filter foam, blocking the air intake?

i havo no way of checking ignition timing at all. There is only 19000 original miles on the bike and from what i can gather without a guage there is compression there. The timing is spot on 305* degrees on the rear as instructed by the service manual. How would i go about checking the ignition timing. And if all else fails i think a rebore is the last option on this.

Will750 09-29-2019 11:30 AM

Quote:

Originally Posted by Spockster (Post 1280263)
Was it the cam timing?

Agree about the spark and pressure. What color is the spark?

Maybe a compression check? Seems that with everything there, you should get at least a nice ka-boom once in a while.

No rats nest, or air filter foam, blocking the air intake?

also there is a nice strong blue spark from all plugs.

Spockster 09-29-2019 12:40 PM

Quote:

Originally Posted by Will750 (Post 1280265)
i havo no way of checking ignition timing at all. There is only 19000 original miles on the bike and from what i can gather without a guage there is compression there. The timing is spot on 305* degrees on the rear as instructed by the service manual. How would i go about checking the ignition timing. And if all else fails i think a rebore is the last option on this.

Do the thumb check on the two shallow spark plugs, put your thumb in the hole and crank it. Would be a good idea to unplug the other spark plug wire, in case it decides to fire with your thumb in there. You should see enough compression to blow your thumb off the hole, if you get nothing, or it's really weak, you'll know that's a problem.

Need a timing light to check ign. timing, but I'm not seeing many ways that could be off. A sheared key on the rotor maybe. Although .... Any chance the pickup coils are mixed up? That would definitely screw up ign. timing.

edit: Another check of the ign timing - With the shallow plug connected and grounded, put your thumb in the hole, crank it. Watch the spark plug for spark to occur at about the same time as the compression on your thumb. If this happens a long time apart, good chance the pickup coils are reversed.

Will750 09-29-2019 01:40 PM

Quote:

Originally Posted by Spockster (Post 1280271)
Quote:

Originally Posted by Will750 (Post 1280265)
i havo no way of checking ignition timing at all. There is only 19000 original miles on the bike and from what i can gather without a guage there is compression there. The timing is spot on 305* degrees on the rear as instructed by the service manual. How would i go about checking the ignition timing. And if all else fails i think a rebore is the last option on this.

Do the thumb check on the two shallow spark plugs, put your thumb in the hole and crank it. Would be a good idea to unplug the other spark plug wire, in case it decides to fire with your thumb in there. You should see enough compression to blow your thumb off the hole, if you get nothing, or it's really weak, you'll know that's a problem.

Need a timing light to check ign. timing, but I'm not seeing many ways that could be off. A sheared key on the rotor maybe. Although .... Any chance the pickup coils are mixed up? That would definitely screw up ign. timing.

edit: Another check of the ign timing - With the shallow plug connected and grounded, put your thumb in the hole, crank it. Watch the spark plug for spark to occur at about the same time as the compression on your thumb. If this happens a long time apart, good chance the pickup coils are reversed.

i will definatly try the compression and spark in a few mins as i have the starter apart to check that. It all looks good so i can rule that out. As for ignition coils beeing reversed. Highly unlikely as i havent taken them off the bike at all. I will report back once i have the starter on it. Also the bike had the ear shave done. Could this have something to do with it.

Spockster 09-29-2019 01:55 PM

Quote:

Originally Posted by Will750 (Post 1280273)
i will definatly try the compression and spark in a few mins as i have the starter apart to check that. It all looks good so i can rule that out. As for ignition coils beeing reversed. Highly unlikely as i havent taken them off the bike at all. I will report back once i have the starter on it. Also the bike had the ear shave done. Could this have something to do with it.

Not the ignition coils, but the pickup coils at the rotor/stator. Could be swapped positions or the maybe the wires mixed up. You had the engine all apart for rebuild, right? If you didn't take the two pickup coils out of the stator case, that just leaves the wires, if they can be mixed up. It's happened before, I'm just not sure in what way they were mixed up.

Earshave shouldn't be the problem, it should at least fire.

Will750 09-29-2019 04:59 PM

Quote:

Originally Posted by Spockster (Post 1280275)
Quote:

Originally Posted by Will750 (Post 1280273)
i will definatly try the compression and spark in a few mins as i have the starter apart to check that. It all looks good so i can rule that out. As for ignition coils beeing reversed. Highly unlikely as i havent taken them off the bike at all. I will report back once i have the starter on it. Also the bike had the ear shave done. Could this have something to do with it.

Not the ignition coils, but the pickup coils at the rotor/stator. Could be swapped positions or the maybe the wires mixed up. You had the engine all apart for rebuild, right? If you didn't take the two pickup coils out of the stator case, that just leaves the wires, if they can be mixed up. It's happened before, I'm just not sure in what way they were mixed up.

Earshave shouldn't be the problem, it should at least fire.

oh right i get you now. This i will definatly try as i had the wires removed during the rebuild. So currently i have a new starter rebuild kit ordered ( same thing when its apart ). And also because of pure frustration with the whole thing i ended up braking the plastic fuel elbow on the carb. Not a biggy as i will just replace them with solid brass ones. Im ordering a carb repair kit also with new jets etc. So after all said and done if it still wont start the only other thing i can think of is compression. Even tho a rebore is easy to get done i am finding to hard to get the pistons here in ireland. I cant get them in the uk either for some reason. Im hoping compression is not the issue as new oversized pistions and rings from the states is coming in at close to 300 euro (350$) for the 2. I will keep this thread updated as i go as it might help someone else in future if i ever get the demon started.

Sparkys73150 09-29-2019 09:32 PM

I know it sounds crazy but, I have a 19hp B&S engine on my wood splitter it was running fine. I welded something on it and when I tried to start it, I got nothing. I changed everything I could think of. I remembered I didn't change the spark plugs. put new plugs in and bingo!!! You might try a set of plugs.


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