Bogging down

[hodakamax]

Taz, did you catch my edit? These things are sometimes not as simple as they first seem. This is all big fun to me because it makes us all think!

Maxie

And Merry Christmas--

[Dale]

Taz,
I think it is great that you have decided to do a rebuild. This thread has discussed break-in, jetting and piston fitment as being critical and it sounds like you plan to address those items. Also mentioned several times are the possibilities of air leaks. An air leak will kill a 2-stroke motor and to prevent one is a simple and cheap test. It is amazing what you can find leaking on these little motors after a rebuild. It is well worth the effort!

There are numerous threads here on how to perform the test and there is also a write-up in the FAQ section on the Strictly Hodaka website. That article is kind of hidden under the title of "Mini Buff"...

Dale

[taz]

Got the old ring out of the piston , nope note broke !

[Zyx]

Just for grins, slip the ring into the top of the bore, square it up with the crown of a piston, and measure the gap with a feeler. Just curious to know what it was or what it would be now. If 0.009" which I believe you said it was set to, it shouldn't have jammed. Still curious to know if the port was chamfered. Something caused lubrication to fail in that area of the exhaust port. Also, after you removed the damaged piston, where on the cylinder was the bulk of the damage, above or below the port. Or both. Just trying to get a sense of what happened so as to avoid a repeat.

[Zyx]

Another question: are we looking at the exhaust side of the piston here? It looks like the ring locating pin is just to the left side of the piston which would put the ring gap just to the right of the exhaust port. I would think that was a crazy place to put a ring locator pin. Not familiar with Wiseco pistons so just asking. Does anyone know for certain where the locator pin should be (if that's what is showing in the photo)? Is it possible the piston was put in backwards???

[taz]

Just for grins, slip the ring into the top of the bore, square it up with the crown of a piston, and measure the gap with a feeler. Just curious to know what it was or what it would be now. If 0.009" which I believe you said it was set to, it shouldn't have jammed. Still curious to know if the port was chamfered. Something caused lubrication to fail in that area of the exhaust port. Also, after you removed the damaged piston, where on the cylinder was the bulk of the damage, above or below the port. Or both. Just trying to get a sense of what happened so as to avoid a repeat.

Gap turns out to be .009 sloppy . The ports are chamfered . there was little marks above the exhaust port half way up , very minor , hone took them off with about 6 go through ! Lucky on that part !

[Zyx]

Does the piston have a cast-in or stamped arrow on top? If so, it points to the exhaust side. Take a look. Verify the piston was installed with the arrow toward the exhaust. I guess I have just never seen a 2-stroke piston with the ring gap forward. Unless it is just the photo that makes it look that way.

[racerclam]

Its important to know at what throttle position the seizure happened , such as
1/2 3/4 full throttle then you would know what circuit of the carb needs tuning. If it happened between 1/8 and 3/4 the needle position or size along with needle jet size would be where your attention should be , if it happened between 3/4 and full throtle it would indicate main jet. Also if you idle was nice and steady I wouldnt suspect an air leak.

Rich

[taz]

Does the piston have a cast-in or stamped arrow on top? If so, it points to the exhaust side. Take a look. Verify the piston was installed with the arrow toward the exhaust. I guess I have just never seen a 2-stroke piston with the ring gap forward. Unless it is just the photo that makes it look that way.

LOLOL Shorty you see it wrong , ring gap was rear off side !! all good there .. LOL and yes I had it the right way ,...

[taz]

Its important to know at what throttle position the seizure happened , such as
1/2 3/4 full throttle then you would know what circuit of the carb needs tuning. If it happened between 1/8 and 3/4 the needle position or size along with needle jet size would be where your attention should be , if it happened between 3/4 and full throtle it would indicate main jet. Also if you idle was nice and steady I wouldnt suspect an air leak.

Rich

Good advice , I believe needle but am also rebuilding bottom end any ways , might as well since I do not know the past of this bike .... Thank you ....

[Zyx]

Darned photos. When I enlarge the shots, they fuzz out, but good to know it was right side around. I hate auto focus devices.

[taz]

Ok Ok Big smiles now ! Seems yes major air leak is what it was ! Have totally rebuilt from bottom up with all new parts and 20 over ! very tight and smooth with awesome compression ! Now for some questions to my wise mentors ! For break in what main jet , pilot jet and placement for clip on needle should I start off on giving the fact that I am at an elevation of 1450 feet ... Also what would be a good fuel / oil ratio to start with ..... Once again Thank you to all the great Hodaka lords out there ..........

[Zyx]

What is your jetting now? How does it compare to the "stock" jetting for your model?

For what it is worth, I don't change jetting for a break-in. You can use a step richer oil mix of you wish, depends on what you are running generally. More important to breaking in an engine is to run it without pushing the limits. It is the time on the clock that breaks the engine parts in to a running condition. So run it modestly. How long depends on how tight you set the engine when you rebuilt it. It has to get to full running temperature, and it needs to cool fully between runs. You can run longer as you go, and push a little harder each time.

Keep in mind that if jetting is in question, it is going to be difficult to properly tune the jetting with a fresh rebuild.

[taz]

Ok bike was not running when I got it and I had to ge a carb from E bay , yes it is the correct carb for this bike , main jet in it is a 150 the needle clip was one high ( lean ) from center .. So I guess I just need a stating point of what I should have in there and so on .... Thanks

[Zyx]

http://www.strictlyhodaka.com/v/vspfile ... 94_94A.jpg


Contains all of the specs for the bike including both types of carb used.