The Unofficial 7.5cc Tunnel Thread
10-09-2011, 08:09 PM
#176
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RE: The Unofficial 7.5cc Tunnel Thread
The Dumas products are quite dated. It will cost you more money, however I'd suggest spending it and getting a much better hull. You can check out the Leecraft XT-460 and the HTB hulls if you haven't done so already.
Ryan
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10-10-2011, 03:46 AM
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RE: The Unofficial 7.5cc Tunnel Thread
i kinda thought so with the dumas products. yea the leecraft and htp hulls are nice but to expensive @ this point in time. not going to be racing just having fun and continue learning. did purchase the newer hotshot sprint for quite a reasonable price. gonna have a go @ it. also dpi hulls are on the lower side of price too. they said they might start producing the 7.5 again in the near future. we'll see.
10-26-2011, 09:21 AM
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RE: The Unofficial 7.5cc Tunnel Thread
drive it out from where the flex shaft goes also a little heat will help as the case will expand faster than the bearrings wont take alot to get them out
10-26-2011, 11:12 AM
#180
RE: The Unofficial 7.5cc Tunnel Thread
I have a little toaster oven I got from a thrift shop I set at about 275 and leave it in there for a few minutes; over 5 less than 10 if I remeber right.
The aluminum will expand before the steel bearing. You have to keep an eye on it because you don't want to warp anything.
Then I use a pair of welding gloves to hold the assembly and tap it on a wood surface, the bearing will almost fall out, if you get the timing right.
Works like a charm but it takes a little longer than you would think to get it hot enough.
When putting it back together I put the bearing in a zip lock bag and put it in the freezer for 10 minutes or so and heat up the housing for about the same.
The bearing will slide right in, no banging at all. You don't want to fool around because it will get tight kindof fast.
Hope this works out for you, I had a heck of a time replacing bearings before I read about this on the MECOA site.
The aluminum will expand before the steel bearing. You have to keep an eye on it because you don't want to warp anything.
Then I use a pair of welding gloves to hold the assembly and tap it on a wood surface, the bearing will almost fall out, if you get the timing right.
Works like a charm but it takes a little longer than you would think to get it hot enough.
When putting it back together I put the bearing in a zip lock bag and put it in the freezer for 10 minutes or so and heat up the housing for about the same.
The bearing will slide right in, no banging at all. You don't want to fool around because it will get tight kindof fast.
Hope this works out for you, I had a heck of a time replacing bearings before I read about this on the MECOA site.
10-31-2011, 06:38 PM
#182
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RE: The Unofficial 7.5cc Tunnel Thread
This may seem dumb to some,but I'm putn together my first outboard....does it matter if the carb is rotated 180 degrees???Older model and wanting to put return spring on it????
10-31-2011, 08:53 PM
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RE: The Unofficial 7.5cc Tunnel Thread
I've needed my carb swapped 180 degrees when I moved the throttle cable to the other side. This should not matter.
Ryan
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11-01-2011, 04:26 AM
#184
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RE: The Unofficial 7.5cc Tunnel Thread
Thanks Ryan,Picked up a LapCat rather cheap and hoping to get it test run Sat.Then I can start preparing for winter rebuild.
11-02-2011, 11:27 AM
#185
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RE: The Unofficial 7.5cc Tunnel Thread
hi brooooos :-) i need manual assembly the prather 32",please,I do not find it to come out mi mail is [email protected]
11-02-2011, 04:22 PM
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RE: The Unofficial 7.5cc Tunnel Thread
The manual of armed with this model,Not nothing on and I want to install an electrical engine (in-board)to him and it is not promoted and propeller can go
11-02-2011, 04:49 PM
#191
RE: The Unofficial 7.5cc Tunnel Thread
Sorry it is obvious you have problems with the english language. You pretty much have to read all the various posts.
If you see this as a lack of respect, mucho bugger brooouski
ALL the information is HERE on RCUniverse! Otherwise buy one already ready to run and copy things?
There was no manual, per se, that tells you how to completely built the lap cat, as far as I know, sorry.
I have the Dumas Hot Shot 21, Lap Cat 3 and had the Hot Shot 45 and there was a 1 page sheet sheet included in the kit, like a blueprint, with a template for drilling the holes in the transom for a K&B outboard engine, a diagram on how to fabricate a throttle cable bracket and a drawing of where to mount the turn fin.
That's it, no manual.
Look at the pictures, ask specific questions, there are a lot of great people to help but you need to ask the right questions!
Good Luck
If you see this as a lack of respect, mucho bugger brooouski
ALL the information is HERE on RCUniverse! Otherwise buy one already ready to run and copy things?
There was no manual, per se, that tells you how to completely built the lap cat, as far as I know, sorry.
I have the Dumas Hot Shot 21, Lap Cat 3 and had the Hot Shot 45 and there was a 1 page sheet sheet included in the kit, like a blueprint, with a template for drilling the holes in the transom for a K&B outboard engine, a diagram on how to fabricate a throttle cable bracket and a drawing of where to mount the turn fin.
That's it, no manual.
Look at the pictures, ask specific questions, there are a lot of great people to help but you need to ask the right questions!
Good Luck
11-02-2011, 04:57 PM
#192
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RE: The Unofficial 7.5cc Tunnel Thread
What I have is all the paperwork that originally came with a boat I purchased,already assembled but do have all paperwork...building instructions,set up,tuning prop balancing and price sheets...ALL ORIGINAL if any helps...let me know
11-02-2011, 05:29 PM
#193
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RE: The Unofficial 7.5cc Tunnel Thread
muchisimas gracias,usted con el castellano anda bien?estuve buscando y este modelo si venia con manual de instrucciones y ensamblado si estoy armando un modelo de los años 80 es obvio que no puedo comprar uno completo y actual hago lo que puedo con lo que tengo in english:yanks you, do you with the Castilian walk well? I was searching and this model if permission with manual of instructions and assembled if I am arming a model of the 80s is obvious that I cannot buy the complete and current one I do what I can with what I have
11-02-2011, 05:34 PM
#194
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RE: The Unofficial 7.5cc Tunnel Thread
It can scan it and send at mi mail,im fro argentine bro,sorry... [email protected] But it can there is no problem,I sit a lack of respect towards those who begin,(Not of you)Already I do not have enthusiasm to arm the model
11-13-2011, 01:01 PM
#195
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RE: The Unofficial 7.5cc Tunnel Thread
hey all. got my hot shot sprint 7.5 kit #1328 built and ran. wow what a difference between the older kit this new one. build turned out awesome. whats a good way to get sponson bottoms sharp. started sanding but started to round off so i quit before i got to far. sealed it up and ran it. ran great and handled well. but what rule of thumb with the sharpening of the sponsons and shaping of stumble blocks. oh yea, how do i post vids and picts? and if any of you guys can post picts of the bottoms of your hulls. got a few good minutes of footage but dont know how to post. will keep trying though youtu.be/TBLt0gLRHeo
11-20-2011, 08:12 PM
#196
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RE: The Unofficial 7.5cc Tunnel Thread
hereare a few picts of the newer hotshot sprint 7.5. took me A little over a month. i was layed off so i had some great build time.
01-17-2012, 09:44 AM
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RE: The Unofficial 7.5cc Tunnel Thread
I really don't believe you will see a large difference. Placing a tuned pipe on the engine will make the most significant difference.
Ryan
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02-17-2012, 02:34 PM
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RE: The Unofficial 7.5cc Tunnel Thread
Hi Ryan,
Thanks for the reply!! I was running a mod k&b ob the other day and lost a flywheel during a run, she took off like a rocket before back flipping and at rescue found was missing a flywheel. It was running the old heavy one but as she ran so hard without one I thought I would try the smaller k&b one that was on some 11cc engines. It still runs good and will blow over-( still needs some weight in the nose I think), but should I run the heavier or lighter flywheel?
Cheers,
Dion.
Thanks for the reply!! I was running a mod k&b ob the other day and lost a flywheel during a run, she took off like a rocket before back flipping and at rescue found was missing a flywheel. It was running the old heavy one but as she ran so hard without one I thought I would try the smaller k&b one that was on some 11cc engines. It still runs good and will blow over-( still needs some weight in the nose I think), but should I run the heavier or lighter flywheel?
Cheers,
Dion.
02-17-2012, 02:41 PM
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RE: The Unofficial 7.5cc Tunnel Thread
The lighter flywheel allows you to accelerate a bit more quickly as response time is decreased. However I enjoyed the ease of the heavier flywheel as I could launch the boat at lower RPM's. It's really a personal preference. Try both and compare. I had both to try.