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Discussion Starter · #1 ·
I have a friend who has a problem with his engine. It has a TB 88cc race head and the cylinder. The other day his chain bound up by his case, he put it back on, kicked it over and it started, but then all sorts of rattling was going on. Then it shut off on him. We took the head an cylinder off and the piston and everything looks good. We put it all back together with gaskets and all and we get a good compression the 1st kick, but it won't start and when you try to kick it over again there is no compression.

We took it all apart again and same thing. So we called the Honda dealership and they said it's something wrong in the head.

Anyone know what might be going on?
 

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He probably broke the pulse pickup off the stator plate. Take off the ignition cover on the left side and assess the damages. Normally, the chain wads up on the sprocket enough to crack or shatter the inside of the ignition cover, which then bends or breaks off the pulse pickup mount, rendering the bike dead in the water.
 

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Discussion Starter · #3 ·
dirtbkr188 said:
He probably broke the pulse pickup off the stator plate. Take off the ignition cover on the left side and assess the damages. Normally, the chain wads up on the sprocket enough to crack or shatter the inside of the ignition cover, which then bends or breaks off the pulse pickup mount, rendering the bike dead in the water.


Is that the black square thing on the lower right side of the flywheel (the Ignition Pulse Generator)? Or does he have to take the flywheel off and check the Stator itself? I'm looking in the service manual.
 

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Yes, that is the little black square thing, and, when you take off the ignition cover, the pulse pickup is visible and solidly mounted. If it is hanging by the blue/white wire, you need just another stator plate, unless you damaged the pickup itself, as well. The stator plate is $26.98 from HERE.
 

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Discussion Starter · #5 ·
dirtbkr188 said:
Yes, that is the little black square thing, and, when you take off the ignition cover, the pulse pickup is visible and solidly mounted. If it is hanging by the blue/white wire, you need just another stator plate, unless you damaged the pickup itself, as well. The stator plate is $26.98 from HERE.


humm... we checked it and it's there in tack. I guess he might have to pull the flywheel off and check out everything there.

Why would this part effect the kicking over of the bike?
 

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Well, 99% of the time, when you wad the chain up around the sprocket, it breaks the pulse pickup and you have no spark. You said you checked everything out when you had the top end off, did you look to see if there was a bent valve? Any damage to the top of the piston? its possible that you bent a valve just enough to not notice it, and that's where you're losing compression.

Here's a little homemade leakdown test I use to see if the valves are seated properly. Level the head up square, and then add a 50/50 antifreeze/water mix to the combustion chamber, and use an old spark plug to fill the hole. I pour it until it "domes" up, as you can see in the pic. I let it sit for 10 minutes minimum, and, if it is still domed up, the valves are seated properly. Even a slightly bent valve will let the liquid disappear rather quickly. It's always worked for me, give it a try.



 

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Here's a picture of 1st gear missing a few teeth...







And, for those of you trying to do a headstand to figure it out, here is a picture of it rightside up...



 

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Always nice to find the problem after a head scratching search. Congrats. He'll be up and running in no time.
 
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