I have made this gasifier at my beginings in wood gasification, its similar to yours, identical actualy, the only difference is there is no firetube houseing and there is a nozzle inside. No restriction. You can see the gas is wery much flamable. imagine this gasifier is your firetube.
Based on the colour of your smoke your fire zone is way to low in the firetube. It shuld be somewhere in the middle of the firetube, yours must be wery low. I dubt wood is the problem.
Allso, you light at the bottom right? This means the gasifier takes a long run time to “draw” the fire up, at wich point the burnt gases can pass the glowing charcoal bed, where the magic actualy happens.
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Thank you so much
But i didn’t understand last case(you need to insert a steel ring in the firetube, outside diameter 10cm (firetube radius), iner diameter about 5 cm.) 
yes i light the pellets exactly at the bottom of the fire tube(i light pellets Inside the basket Through the ignite pipe)
The modifications on top drawing will make flamable gas! If you insert the ring (called restriction) like seen here, your gas will allso contain much less tar! https://goo.gl/images/c6inSd
Restriction concentrates the produced temperature/gas velocity, wich in term destroy/crack/burn tar and aids to stronger, cleaner gas. Can be done eithout it thugh!
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Thank you so much 
I understood
i will repair it tomorrow
Can I use wood in this system?
Because I’m not sure about the quality of the pellet because my pellets has 10% of the stucco for pressing process
Hello mr tom collins
We research about Combustion gases in gasifier process,it is not necessary to Launching the engine.we just want to compress gas in cylinder
Yes, but the wood shuld be about cherry size, no bigger. Chips you show in the filter are too long and narrow and will not flow/fall well inside.
Idealy you want at least 2 opposite air nozzles, so that the air streems meet in the center, but start with one, you will get fire for sure!
Do not forget to fill the hearth with fine charcoal at first run! This is esential! Once you have it in, you never need to ad it again.
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If I understand your machine, I had one similar. It liked pellets and chips also worked as long as they were small. It would start fast.
Fill 1/3 to 1/2 with charcoal.
Start proper air draft
Light the top of the charcoal. All top diameter red glowing.
Place thin layer of pellets on top.
After 30 seconds to 1 minute the flat will light with proper burner.
Later I will see if I can find pictures.
You will graduate ! ! After all, we all have made it.
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Tnank you so much
Hello steve
I will certainly try your suggestions in the next few days
I hope to be successful
Thank you so much
Hi Saman , at about 36 seconds into the video you show us your condensate jar , and also a drip of what looks to be tar running down the outside of the glass , do you have a pin hole leak there ? i know for sure that sometimes the smallest of air leaks will cause it to explode with a loud bang or even not make burnable gas , can you reverse the fan and blow through the whole system before you next light it and check everywhere for air leaks with soapy water and look out for bubbles .
Dave
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Jeff says ‘‘start a proper air draft’’ and that is very important. I used and modified several fans of the type you are showing. They often do not create a proper draft. You need a water monometer in the piping close to the gasifier. You need a draft of between 5 and 10 inches of water column. TomC
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Hi dave
Yes i have to check my system again.
Especially about airtight.
Thank you
Which kind of fan do you introduce?
Capacity?cfm? etc
But it do suction good.
Thank you
First off you need to hook a clear plastic tube to the pipe line and stick the other end in a cup of water. Measure how high the water comes up out of the cup under vacuum. The closer you can put the tube to the gasifier the better. If you hook it up close to the fan you will get a reading of how much the fan is putting out but if you have any leaks in the system the vacuum can be much less at the gasifier itself.
I prefer a household or shop vac with a “light dimmer” switch wired into the feed line so I can control the vacuum. TomC
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My gasifier was an open top. If I drafted too much the charcoal would be consumed and the gas will not burn. It was not a charcoal gasifier. I do not remember the inch/water draw amount but it was low, maybe below 5. Maybe not. Easier to make excess charcoal and shake or auger it out. The oxidation zone can not leave the raw fuel. Always worked best with about 8 cm (or less) of raw fuel above the glowing oxidation zone.
You will be able to gasify just about anything for thermal use. Must be small particle size and dry.
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It also help, for my gasifier, if the charcoal I started with was made from the fuel stock that I was going to feed the gasifier. So, if wood chips I made charcoal from those wood chips, if rice husks I made rice husk charcoal. Made life easier.
Your gasifier needs a charcoal bed to start with. Then add the raw dry fuel on top.
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That statement isn’t exactly correct. If it was drafted too strong the charcoal bed will be exhausted. Remember, no charcoal - no gasification.
Looks like I’ll have to unpack an old computer in order to find those old photo, maybe a video.
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Yes this is a good way to test my system.
But i test it later.
Thanks
Hi jeff
i want to close firetube top and use the air nuzzles,And of course I use Charcoal
But i have a question?
Will I ignite the coal and then I’ll throw it in the firetube?
Or pour the charcoal and after that I ignite it through the ignite tube(air nuzzle)?
Thank you