Help with a Tiger jet

[chalo]

Hi Guys

I have a Tiger jet new, never run still shining. My problem is that this little PJ refuses to start, just a few bangs . I`m not a novice i have a Dynajet and starts very easy with one or two shots of air from my compresor; i suspect the problem has to do with the combustion chamber/tail pipe length, this one has around of 16" and all the plans of tigerjets clearly show a combustion chamber/tail pipe length of 18.875". Still has the original reed valve and is in good shape, i also have made some more valves by myself but no difference is noted.

Has somebody made work one of these? i always see youtube videos showing working Dynajets or similar sized ones but never seen a Tiger jet working.

Any input will be appreciated



Thanks in advance
Gonzalo M

[Mark]

I have a Tiger that is 17 inches long excluding the head. I've run it on regular gasoline. The metering jet is quite fine, perhaps there could be a particle partially blocking the flow. Another thing I did was to push up each petal with a blunt rod of some sort to flex the reeds a bit in case they were too stiff. I can't think of what else to try really. Have the fuel level close to the metering jet and watch for it to advance when you puff in starting air. I had a Dynajet that I had lightly coated the reeds with oil to prevent rusting when I put it away for months. This slight bit of oil prevented it from starting. I had to take the reeds off and clean them and then it started right up. Just a little bit of oil will inhibit the fluttering.
Perhaps the tailpipe end was damaged and the tip with the flare cut off. I can't see it that clearly if there is a flare on your Tigerjet tail or not. If that is the case you might try attaching a short piece of tailpipe with a flared end about 1.5 inches long.
I think they made the TIger in two different versions or different lengths.
Here's a picture of my Tigerjet in the middle. Notice the steel ring that is threaded on the red head is much thinner than your design. I have seen both variations for sale on eBay in the past. Seems I recall someone said in the slightly shorter length Tigerjet the reeds didn't last as long.
It looks like there isn't much room left in your box for a longer jet. And again, I can't see the flare but perhaps it is there.

[Mark]

I recall with my Tigerjet I didn't really like the spark plug that came with it. Sometimes instead of arcing, electricity will crawl over to the other electrode to some extent, maybe if wet, corroded, or dirty. It may not be "the" factor, but sometimes a good spark can help, if other elements are against you. I switched mine out with a 1/4 32 rimfire plug.

[chalo]

Hi Mark

Thanks you for taking the time to share your opinion. I followed your advice and made an entire cleaning of the jet meter and the fuel lines, also i open a little the valves to help enter the fuel/air charge ; one thing i forgot to mention was that i change the original plug for a rimfire spark plug because the original was more of the glow style with filament and i`m using unleaded gas for running. Also i was checking the tail end in search of any sign of modifications and seems to be original even with the flare. Certainly i also have seen at least 2 versions of the small tigerjet, one like yours with the lock ring just like the Dynajet and the mine with a wider ring made of aluminiun with excesive play of the treads due to poor machining, i have made a gasket to seal the best i can the head with the combustion tube. Perhaps my version was a first batch with the combustion tube too short and later versions added a little more tube to make it more user friendly.

I going to try to make a telescopic tube to test diferent tail lengths starting in around 20" and reducing the lenght by 1/4" each time. If time permits, i will make the test before this year ends.

As soon i have some data i will post here

Regards

Gonzalo M.

[Mark]

Seems like your jet should start if your gasket material seals the combustion chamber. I wouldn't modify/lengthen the jet just yet since it was designed and sold to run as is. When I mentioned flexing the reeds to take some of the stiffness out, you don't want to flex them too much or bend them which would then keep them from sealing of course. Once the jet backfires a few times the heat should help make starting easier.
I've always been impressed how loud my Tigerjet is for so small and as light as it is.
Good luck.

[noclassmac1972]

Hi I would try another type of fuel the unleaded gas from the pump is very difficult to start with the little jets. The original gas they used is what we call in NZ White spirits or I think in the US coleman lighter fluid??? try this if you can?? Also the valves need to seal well. Try blowing down the tailpipe to check for leaks, should be like blowing into a wine bottle.. I also stick the head into a bucket of water to check for leaks sometimes... The tigre jet you have is the M1 while mark has the M2 I had a M1 but sold it now only have a M2

Regards
Robert Bolton ( new zealand)

[Mark]

One time on a lark I started my Tigerjet using methanol by sleeving a silicone fuel line over the starting air blowpipe fitting and injecting air in from an air compressor nozzle. As crude as the offset fueling was, it seemed to run fine. I guess if you were going to run methanol in a normal/practical manner, you would need to allow more fuel flow than what the gasoline metering diameters provide - the fuel/air ratio being different.